微信公众号随时随地查标准

QQ交流1群(已满)

QQ群标准在线咨询2

QQ交流2群

购买标准后,可去我的标准下载或阅读

This specification covers standard requirements for welded austenitic stainless steel feedforward heater tubes including those bent, if specified, into the form of U-tubes for application in tubular feed-water heaters. All finished straight tubing or straight tubing ready for U-bending shall be furnished in the solution-annealed condition. The steel shall conform to the required chemical composition for carbon, phosphorus, chromium, molybdenum, nitrogen, and copper. The material shall also conform to tensile properties such as tensile strength, yield strength, and elongation. The steel shall undergo mechanical tests such as tension test, hardness test, reverse bend test, flattening test, flange test, pressure test, hydrostatic test, and air underwater test. Nondestructive test (electric test) shall be performed and corrosion resisting properties shall be determined for each sample tube.1.1 This specification2 covers seamless and welded austenitic stainless steel feedwater heater tubes including those bent, if specified, into the form of U-tubes for application in tubular feed-water heaters.1.2 The tubing sizes covered shall be 5/8 to 1 in. [15.9 to 25.4 mm] inclusive outside diameter, and average or minimum wall thicknesses of 0.028 in. [0.7 mm] and heavier.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

This specification covers several different types of chemical passivation treatments for stainless steel parts. The treatments are the following: immersion treatment using nitric acid solutions, immersion treatment using citric acid solution, and electrochemical treatment. Immediately after the removal from the passivating solution, the parts shall be thoroughly rinsed, using stagnant, countercurrent, or spray washes, singly or in combination, with or without a separate chemical treatment for neutralization of the passivation media. The chemical reactions of the passivating media on the surface of the stainless steel shall be stopped by rinsing of the stainless steel part, with or without a separate neutralization treatment. A chemical treatment shall be applied which will accelerate the formation of the passive film on a chemically clean stainless steel surface. The passivated parts shall exhibit a chemically clean surface and shall, on visual inspection, show no etching, pitting, or frosting. The following tests shall be performed on each lot of stainless steel parts: water immersion test, high humidity test, salt spray test, copper sulfate test, and potassium ferricyanide-nitric acid test. A free iron test shall be used for the detection of free iron on the surface of stainless steel.1.1 This specification covers several different types of chemical passivation treatments for stainless steel parts. It includes recommendations and precautions for descaling, cleaning, and passivation of stainless steel parts. It includes several alternative tests, with acceptance criteria, for confirmation of effectiveness of such treatments for stainless steel parts.1.2 Practices for the mechanical and chemical treatments of stainless steel surfaces are discussed more thoroughly in Practice A380/A380M.1.3 Several alternative chemical treatments are defined for passivation of stainless steel parts. Appendix X1 and Appendix X2 give some nonmandatory information and provides some general guidelines regarding the selection of passivation treatments appropriate to particular grades of stainless steel. This specification makes no recommendations regarding the suitability of any grade, treatment, or acceptance criteria for any particular application or class of applications.1.4 The tests in this specification are intended to confirm the effectiveness of passivation, particularly with regard to the removal of free iron and other exogenous matter. These tests include the following practices:1.4.1 Practice A—Water Immersion Test,1.4.2 Practice B—High Humidity Test,1.4.3 Practice C—Salt Spray Test,1.4.4 Practice D—Copper Sulfate Test,1.4.5 Practice E—Potassium Ferricyanide-Nitric Acid Test, and1.4.6 Practice F—Damp Cloth Test, and1.4.7 Practice G—Boiling Water Immersion Test.NOTE 1: Free iron denotes iron present on the surface of the parts, including but not limited to iron contamination, iron-tool marks, residual-iron salts from pickling solutions, iron dust, atmospheric exposure, iron deposits in welds, embedded iron, and iron oxide.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

This specification covers the chemical, mechanical, and metallurgical requirements for wrought 18chromium-14nickel-2.5molybdenum stainless steel sheet and strip used for the manufacture of surgical implants. Sheet and strip shall be furnished as specified, in the annealed or cold-worked condition. Types of finish available in sheet and strip are dull cold rolled, bright cold rolled, intermediate polished, general-purpose polished, dull satin-finished, high luster finish, and mirror finish. Tensile test, hardness test, and intergranular corrosion susceptibility test shall be performed in accordance with specified requirements.1.1 This specification covers the chemical, mechanical, and metallurgical requirements for wrought 18chromium-14nickel-2.5molybdenum stainless steel sheet and strip used for the manufacture of surgical implants.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

This guide covers standard specification for precipitation-hardening stainless steel plate, sheet, and strip. The mechanical properties of these steels shall be developed by suitable low-temperature heat treatments or precipitation hardening. The steel shall conform to the required chemical composition for carbon, manganese, phosphorus, sulfur, silicon, chromium, nickel, aluminum, molybdenum, titanium, copper, and other elements. Material of types other than Type UNS S46910 shall be furnished in solution-annealed condition while Type UNS S46910 shall be furnished in cold-worked condition. The steel shall conform to the required mechanical properties such as tensile strength, yield strength, elongation, and hardness. Samples cut from the solution-annealed plate, sheet, or strip shall withstand cold bending without cracking on the outside of the bent portion. Samples cut from the solution-annealed plate, sheet, or strip shall conform to the specified mechanical properties when precipitation hardened.1.1 This specification2 covers precipitation-hardening stainless steel plate, sheet, and strip. The mechanical properties of these steels are developed by suitable low-temperature heat treatments generally referred to as precipitation hardening.1.2 These steels are used for parts requiring corrosion resistance and high strength at room temperature or at temperatures up to 600 °F (315 °C). Some of these steels are particularly suitable for moderate to severe drawing and forming in the solution-treated condition. Others are capable of mild forming only. They are suitable for machining in the solution-annealed condition, after which they may be hardened to the mechanical properties specified in this standard without danger of cracking or distortion.1.3 The values stated in inch-pound units are to be regarded as the standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

5.1 The ability of sintered powder metallurgy stainless steel parts/specimens to resist corrosion when immersed in sodium chloride solution is important to their end use. Causes of unacceptable corrosion may be incorrect alloy, contamination of the parts by iron or some other corrosion-promoting material or improper sintering of the parts (for example, undesirable carbide and nitride formations caused by poor lubricant burnoff or improper sintering atmosphere).5.2 This standard may be part of a purchase agreement between the PM parts producer and the purchaser of the parts (Method 1). It may also be used to optimize part or specimen production parameters (Method 2).1.1 These test methods cover a procedure for evaluating the ability of sintered PM stainless steel parts/specimens to resist corrosion when immersed in a sodium chloride (NaCl) solution.1.2 Corrosion resistance is evaluated by one of two methods. In Method 1, the stainless steel parts/specimens are examined periodically and the time to the first appearance of staining or rust is used to indicate the end point. In Method 2, continued exposure to the sodium chloride solution is used to monitor the extent of corrosion as a function of time.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

This specification covers stainless steel bars for compressor and turbine bucket, blade, and airfoil applications. Materials shall be produced by basic electric furnace melting process with argon-oxygen-decarburization refining or by vacuum ladle degassing. Electro-slag remelting shall also be conducted unless otherwise specified by the purchaser. Two complete heat treatments, consisting of an austenize, quench, and temper, shall be conducted. Straightening, stress relieving, and water or oil quenching shall be executed as well. Steel bars shall adhere to chemical composition and mechanical property requirements, including tensile strength, yield strength, elongation, reduction of area, impact strength, and Brinell hardness.1.1 This specification covers stainless steel bars for compressor and turbine bucket, blade, and airfoil applications.1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

定价: 0元 / 折扣价: 0

在线阅读 收 藏

This specification establishes the requirements for additive manufacturing of stainless steel alloy (UNS S31603) components by means of laser and electron beam-based full melt powder bed fusion processes. The components produced by these processes are typically used in applications that require mechanical properties similar to machined forgings and wrought products. Components manufactured to this specification are often, but not necessarily, post processed via machining, grinding, electrical discharge machining (EDM), polishing, and so forth to achieve desired surface finish and critical dimensions.1.1 This specification covers additive manufacturing of UNS S31603 components by means of laser and electron beam-based full melt powder bed fusion processes. The components produced by these processes are used typically in applications that require mechanical properties similar to machined forgings and wrought products. Components manufactured to this specification are often, but not necessarily, post processed via machining, grinding, electrical discharge machining (EDM), polishing, and so forth to achieve desired surface finish and critical dimensions.1.2 This specification is intended for the use of purchasers or producers, or both, of additively manufactured UNS S31603 components for defining the requirements and ensuring component properties.1.3 Users are advised to use this specification as a basis for obtaining components that will meet the minimum acceptance requirements established and revised by consensus of the members of the committee.1.4 User requirements considered more stringent may be met by the addition to the purchase order of one or more supplementary requirements, which may include, but are not limited to, those listed in Supplementary Requirements S1–S16.1.5 The compositional requirements specified in this specification do not meet the compositional requirements for surgical implant grade UNS S31673.1.6 The values stated in SI units are to be regarded as the standard. Other units are included only for informational purposes.1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

This specification covers the standard for stainless and heat-resisting chromium-nickel steel plate, sheet, and strip. The steel shall conform to the requirements as to chemical composition in carbon, manganese, phosphorus, sulfur, silicon, chromium, nickel, and molybdenum. The material shall also conform to the mechanical properties such as tensile strength, yield strength, elongation, and hardness.1.1 This specification covers stainless and heat-resisting chromium-nickel steel plate, sheet, and strip.1.2 The values stated in inch-pound units are to be regarded as the standard.Note 1—Grades that were previously covered in both Specifications A 167 and A 240/A 240M have been removed from this specification and may now be supplied and purchased in compliance with Specification A 240/A 240M. The chemical and mechanical property requirements of these grades were identical in Specifications A 167 and A 240/A 240M at the time of removal from Specification A 167.

定价: 0元 / 折扣价: 0

在线阅读 收 藏

This specification covers age-hardening stainless steel forgings for general use. Materials for forgings shall consist of billets or bars and shall either be forged, rolled, or cast or a section cut from an ingot. The steel specimens shall be solution annealed and age hardened and shall conform to the required values of tensile strength, yield strength, elongation, reduction of area, hardness and impact Charpy-V. The steel materials shall conform to the required chemical compositions of carbon, manganese, phosphorus, sulfur, silicon, chromium, nickel, aluminum, molybdenum, titanium, copper, nitrogen, columbium, and tantalum.1.1 This specification2 covers age-hardening stainless steel forgings for general use.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.3 Unless the order specifies an “M” designation, the material shall be furnished to inch-pound units.NOTE 1: Bar products are covered by Specification A564/A564M.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

4.1 Insulations that are used as a part of the thermal insulation system in contact with austenitic stainless steels have the potential to become contaminated with water soluble corrosive ions which, in turn, if permitted to reach the stainless steel surface, are possible to contribute to external stress corrosion cracking (ESCC). Therefore, it is important to reduce the exposure of such insulating materials to water-soluble corrosive ion compounds at all stages of manufacture, handling, shipping, storage, and application. During manufacture, precautions shall be taken to minimize water soluble corrosive ion content, both in the material and as surface contamination. Once the manufacture is complete, care must be exercised during handling, transporting, shipping, storage, receiving, and application to avoid contamination with corrosive ions that can be transported by water through the insulation materials onto the stainless steel surface. This practice presents criteria which, if followed, will minimize the risks of ESCC associated with the application of insulation materials. It must be emphasized, however, that because of the many variable factors present, complete freedom from ESCC can not be assured under all circumstances, even when following the guidance of this practice.4.2 Continued protection of the insulation and the stainless steel surface from moisture and contamination after the insulation system is installed and over its entire service life is of significant importance. In-service contamination has the potential to occur from many sources; for example, from airborne contaminates, rain or salt spray, periodic fire sprinkler system tests, wash-downs, or process leakage. Weather barrier jacketing systems and proper application shall be chosen to provide long-term protection in the intended use environment.4.3 The entire insulation system shall be periodically inspected and maintained. Insulation that is suspected of contamination shall be retested or immediately replaced. Wash down of insulated pipe and equipment shall be avoided. Whenever possible, protective coatings or finishes shall be applied directly to the stainless steel surface as the primary source of corrosion protection.1.1 This practice is intended to provide guidance and direction in the handling, transporting, shipping, storage, receiving, and application of thermal insulating materials to be used as a surface treatment or as part of the thermal insulation system in contact with austenitic stainless steel.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 515元 / 折扣价: 438 加购物车

在线阅读 收 藏

This specification covers stainless steel forgings for compressor and turbine bucket, blade, and airfoil applications. The stainless steel shall be made by the melting process and either the closed impression die or the open die forging processes may be utilized. Two complete heat treatments, consisting of an austenize, quench, and temper, are permitted. When heat treatment for mechanical properties is followed by straightening, a stress-relieving heat treatment is required. The forgings shall be subjected to tension, impact, hardness, and non-destructive tests. All forgings shall be free of cracks, seams, laps, shrinkage, and similar discontinuities.1.1 This specification covers stainless steel forgings for compressor and turbine bucket, blade, and airfoil applications.1.2 This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract specifies the applicable M designation (SI units), the inch-pound units shall apply. The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 515元 / 折扣价: 438 加购物车

在线阅读 收 藏

This specification covers hot isostatically-pressed, powder metallurgy, stainless steel piping components such as flanges, fittings, valves, and similar parts, for use in pressure systems and temperature service applications. The specification includes several grades of martensitic, austenitic, age hardening, and austenitic-ferritic stainless steels. Compacts shall be manufactured by placing a single powder blend into a can, evacuating the can, and sealing it. The powder shall be prealloyed and made by a melting method (such as but not limited to air or vacuum induction melting, followed by gas atomization) to produce the specified chemical composition for carbon, manganese, phosphorus, sulfur, nickel, chromium, molybdenum, columbium, tantalum, copper, tungsten, and nitrogen. Other manufacturing requirements including compact homogeneity, microstructure, and can material removal are given. Heat treatment requirements, such as austenitizing or solutioning, cooling, quenching, tempering, and ageing, and structural integrity requirements, such as density, hydrostatic tests, and ultrasonic tests are detailed as well. Mechanical properties include tensile strength, yield strength, elongation, and hardness. Product analysis shall conform to the chemical requirements.1.1 This specification covers hot isostatically-pressed, powder metallurgy, stainless steel piping components for use in pressure systems. Included are flanges, fittings, valves, and similar parts made to specified dimensions or to dimensional standards, such as in ASME specification B16.5.1.2 Several grades of martensitic, austenitic, age hardening, and austenitic-ferritic stainless steels are included in this specification.1.3 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply only when specified individually by the purchaser in the order.1.4 This specification is expressed in both inch-pound units and in SI units. Unless the order specifies the applicable “M” specification designation (SI units), however, the material shall be furnished to inch-pound units.1.5 The values stated in either inch-pound units or SI units are to be regarded separately as the standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.6 The following safety hazards caveat pertains only to test methods portions 8.1, 8.2, 9.5 – 9.7, and Section 10 of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 646元 / 折扣价: 550 加购物车

在线阅读 收 藏

This specification covers the chemical and mechanical requirements for stainless steel and nickel alloy bolts, hex cap screws, and studs intended for use in applications where resistance to heat and the effects of high temperature are to be considered. Three types of materials covered in this specification are: Type I—heat resisting alloys for continuous service applications; Type II—heat resisting alloys for continuous and intermittent service applications; and Type III—high temperature alloys for continuous and intermittent service applications. Type I is classified further into Class A—austenitic grades, Class B—martensitic grades, and Class C—ferritic grades. Type III is also classified further into Class A—nickel based alloy, Class B—precipitation hardened alloy, and Class C—precipitation hardened alloy. The products shall be subject to: chemical analysis; mechanical tests to determine yield strength, wedge tensile strength, or axial tensile strength; and corrosion resistance tests to determine freedom from precipitated carbides.1.1 This specification covers the chemical and mechanical requirements for stainless steel and nickel alloy bolts, hex cap screws, and studs, 1/4 in. diameter and larger, intended for use at temperatures up to 1800°F (982°C), and in applications where resistance to heat and the effects of high temperature are to be considered. See Appendix X1 for Service Application. A wide variety of materials are covered in this specification which can be used at high temperatures as a function of the specific alloy properties, as well as environmental requirements including corrosive environments.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

This practice covers the standard recommendations and precautions for cleaning, descaling, and passivating of new stainless steel parts, assemblies, equipment, and installed systems. Consideration shall be given in the design of parts, equipment, and systems that will require cleaning to minimize the presence of areas in which dirt, or cleaning solutions might become trapped, and to provide for effective circulation and removal of cleaning solutions. Materials shall be precleaned. Scales shall be removed through chemical descaling, acid pickling, and mechanical descaling. Degreasing and general cleaning shall be accomplished by immersion in, swabbing with, or spraying with alkaline, emulsion, chelate, acid, solvent, or detergent cleaners or a combination of these; by vapor degreasing; by ultrasonics using various cleaners; by steam, with or without a cleaner; or by high-pressure water-jetting. Recommended cleaning practices shall be followed for welds and weld-joint areas, specially critical applications, installed systems and post-erections. The following shall be used as the basis for cleanness acceptability: Visual inspection; wipe tests; residual pattern; water-break test; free iron test such as water-wetting or drying; high-humidity test; and copper sulfate test. Precision inspection shall be performed by solvent-ring test, black light inspection, atomizer test, and ferroxyl test. Precaution shall always be practiced to minimize iron contamination, in reuse of cleaning and pickling solution, in water rinsing, in circulation of cleaning solutions and rinse water, in protection of cleaned surfaces, for safety, and disposal of used solutions and water.1.1 This practice covers recommendations and precautions for cleaning, descaling, and passivating of new stainless steel parts, assemblies, equipment, and installed systems. These recommendations are presented as procedures for guidance when it is recognized that for a particular service it is desired to remove surface contaminants that may impair the normal corrosion resistance, or result in the later contamination of the particular stainless steel grade, or cause product contamination. The selection of procedures from this practice to be applied to the parts may be specified upon agreement between the supplier and the purchaser. For certain exceptional applications, additional requirements which are not covered by this practice may be specified upon agreement between the supplier and the purchaser. Although they apply primarily to materials in the composition ranges of the austenitic, ferritic, martensitic, and duplex stainless steels, the practices described may also be useful for cleaning other metals if due consideration is given to corrosion and possible metallurgical effects.1.1.1 The term passivation is commonly applied to several distinctly different operations or processes relating to stainless steels. In order to avoid ambiguity in the setting of requirements, it may be necessary for the purchaser to define precisely the intended meaning of passivation. Some of the various meanings associated with the term passivation that are in common usage include the following:1.1.1.1 Passivation is the process by which a stainless steel will spontaneously form a chemically resistant surface when exposed to air or other oxygen-containing environments. It was at one time considered that an oxidizing treatment was necessary to establish this passive metal oxide film, but it is now accepted that this film will form spontaneously in an oxygen-containing environment providing that the surface has been thoroughly cleaned or descaled.1.1.1.2 Passivation is removal of exogenous iron or iron compounds from the surface of a stainless steel by means of a chemical dissolution, most typically by a treatment with an acid solution that will remove the surface contamination but will not significantly affect the stainless steel itself. This process is described in a general way in 6.2.11 and defined precisely in 6.4 with further reference to the requirements of Annex A2 and Part II of the table on acid cleaning of steel. Unless otherwise specified, it is this definition of passivation that is taken as the meaning of a specified requirement for passivation. (See also Specification A967/A967M.)1.1.1.3 Passivation is the chemical treatment of a stainless steel with a mild oxidant, such as a nitric acid solution, for the purpose of enhancing the spontaneous formation of the protective passive metal oxide film. Such chemical treatment is generally not necessary for the formation of the passive metal oxide film.1.1.1.4 Passivation does not indicate the separate process of descaling as described in Section 5, although descaling may be necessary before passivation can be effective. Depending on the application, chemical descaling (acid pickling) as described in 5.2.1 may provide sufficient passivation as defined in 1.1.1.2.1.2 This practice does not cover decontamination or cleaning of equipment or systems that have been in service, nor does it cover descaling and cleaning of materials at the mill. On the other hand, some of the practices may be applicable for these purposes. While the practice provides recommendations and information concerning the use of acids and other cleaning and descaling agents, it cannot encompass detailed cleaning procedures for specific types of equipment or installations. It therefore in no way precludes the necessity for careful planning and judgment in the selection and implementation of such procedures.1.3 These practices may be applied when free iron, oxide scale, rust, grease, oil, carbonaceous or other residual chemical films, soil, particles, metal chips, dirt, or other nonvolatile deposits might adversely affect the metallurgical or sanitary condition or stability of a surface, the mechanical operation of a part, component, or system, or contaminate a process fluid. The degree of cleanness required on a surface depends on the application. In some cases, no more than degreasing or removal of gross contamination is necessary. Others, such as food-handling, pharmaceutical, aerospace, and certain nuclear applications, may require extremely high levels of cleanness, including removal of all detectable residual chemical films and contaminants that are invisible to ordinary inspection methods.NOTE 1: The term “iron,” when hereinafter referred to as a surface contaminant, shall denote free iron.1.4 Attainment of surfaces that are free of iron, metallic deposits, and other contamination depends on a combination of proper design, fabrication methods, cleaning and descaling, and protection to prevent recontamination of cleaned surfaces. Meaningful tests to establish the degree of cleanness of a surface are few, and those are often difficult to administer and to evaluate objectively. Visual inspection is suitable for the detection of gross contamination, scale, rust, and particulates, but may not reveal the presence of thin films of oil or residual chemical films. In addition, visual inspection of internal surfaces is often impossible because of the configuration of the item. Methods are described for the detection of free iron and transparent chemical and oily deposits.1.5 This practice provides definitions and describes practices for cleaning, descaling, and passivation of stainless steel parts. Tests with acceptance criteria to demonstrate that the passivation procedures have been successful are listed in 7.2.5 and 7.3.4, and can also be found in Specification A967/A967M.1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (For more specific safety precautions see 7.2.5.3, 7.3.4, Section 8, A1.7, and A2.11.)1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 646元 / 折扣价: 550 加购物车

在线阅读 收 藏

This specification covers the passivation by electropolishing of stainless steel alloys in the 200, 300, and 400 series, as well as precipitation-hardened alloys. Basis materials shall be free of clearly visible defects, and if necessary, shall undergo preparatory cleaning procedures prior to electropolishing. Post-coating procedures such as post dip and final rinsing shall be performed as well. The performance of the specimens during passivation shall be evaluated by one or more of the following procedures: water immersion test; humidity test; salt spray test; copper sulfate test; and modified ferroxyl test for free iron.1.1 This specification covers the passivation of stainless steel alloys in the 200 (UNS2XXXX), 300 (UNS3XXXX), and 400 (UNS4XXXX) series, and the precipitation-hardened alloys, using electropolishing procedures.NOTE 1: Surface passivation occurs simultaneously with electropolishing under proper operating conditions. The quality of passivation will depend on the type of stainless steel, the formulation of the electropolishing solution, and the conditions of operation. Free iron on the surface of the stainless steel is removed resulting in improved corrosion resistance. Surface smoothing obtained by electropolishing will also improve corrosion resistance. Electropolishing will also remove heat tint and oxide scale.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This specification may involve hazardous materials, operations, and equipment. This specification does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 515元 / 折扣价: 438 加购物车

在线阅读 收 藏
156 条记录,每页 15 条,当前第 1 / 11 页 第一页 | 上一页 | 下一页 | 最末页  |     转到第   页