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

5.1 PCRT Applications and Capabilities—PCRT has been applied successfully to a wide range of NDT applications in the manufacture and maintenance of metallic and non-metallic parts. Examples of anomalies detected are discussed in 1.1. PCRT has been shown to provide cost effective and accurate NDT solutions in many industries including automotive, aerospace, and power generation. Examples of successful applications currently employed in commercial use include, but are not limited to:(1) Silicon nitride bearing elements(2) Steel, iron, and aluminum rocker and control arms(3) Aircraft and industrial gas turbine engine components (blades, vanes, disks)(4) Cast cylinder heads and cylinder blocks(5) Sintered powder metal gears and clutch plates(6) Machined forged steel steering and transmission components (gears, shafts, racks)(7) Ceramic oxygen sensors(8) Silicon wafers(9) Gears, including those with induction hardened or carburized teeth(10) Ceramic matrix composite (CMC) material samples and components(11) Components with shot peened surfaces(12) Machined or rolled-formed fasteners(13) Components made with additive manufacturing(14) Aircraft landing gear, wheel, and brake components(15) Components made with metal injection molding5.2 General Approach and Equipment Requirements for PCRT via Swept Sine Input: 5.2.1 PCRT systems comprise hardware and software capable of inducing vibrations, recording the component response to the induced vibrations, and executing analysis of the data collected. Inputting a swept sine wave into the part has proven to be an effective means of introducing mechanical vibration and can be achieved with a high quality signal generator coupled with an appropriate active transducer in physical contact with the part. Collection of the part’s frequency response can be achieved by recording the signal generated by an appropriate passive vibration transducer. The software required to analyze the available data may include a variety of suitable statistical analysis and pattern recognition tools. Measurement accuracy and repeatability are extremely important to the application of PCRT.5.2.2 Hardware Requirements—A swept sine wave signal generator and response measurement system operating over the desired frequency range of the test part are required with accuracy better than 0.002 %. The signal generator should be calibrated to applicable industry standards. Transducers must be operable over same frequency range. Three transducers are typically used; one Drive transducer and two Receive transducers. Transducers typically operate in a dry environment, providing direct contact coupling to the part under examination. However, non-contacting response methods can operate suitably when parts are wet or oil-coated. Other than fixturing and transducer contact, no other contact with the part is allowed as these mechanical forces dampen certain vibrations. For optimal examination, parts should be placed precisely on the transducers (generally, ±0.062 in. (1.6 mm) in each axis provides acceptable results). The examination nest and cabling shall isolate the Drive from Receive signals and ground returns, so as to not produce (mechanical or electrical) cross talk between channels. Excessive external vibration or audible noise, or both, will compromise the measurements.5.3 Constraints and Limitations: 5.3.1 PCRT cannot separate parts based on visually detectable anomalies that do not affect the structural integrity of the part. It may be necessary to provide additional visual inspection of parts to identify these indications.5.3.2 Excessive process variation of parts may limit the sensitivity of PCRT. For example, mass/dimensional variations exceeding 5 % may cause PCRT to be unusable.5.3.3 Specific anomaly identification is highly unlikely. PCRT is a whole body measurement and differentiating between a crack and a void in the same location is generally not possible. It may be possible to differentiate some anomalies by using multiple patterns and training sets. The use of physics-based modeling and simulation to predict the resonance frequency spectrum of a component may also allow relationships between resonance frequencies and defect locations/characteristics to be established.5.3.4 PCRT will only work with stiff objects that provide resonances whose frequency divided by their width at half of the maximum amplitude (Q) are greater than 400 to 500. Although steel parts may be very stiff and perfectly reasonable to use for PCRT, steel foil would generally not be.5.3.5 While PCRT can be applied to painted and coated parts in many cases, the presence of some surface coatings such as vibration-absorbing materials and heavy oil layers may limit or preclude the application of PCRT.5.3.6 While PCRT can be applied to parts over a wide range of temperatures, it should not be applied to parts that are rapidly changing temperature. The part temperature should be stabilized before collecting resonance data.5.3.7 Misclassified parts in the teaching set, along with the presence of unknown anomalies in the teaching set, can significantly reduce the accuracy and sensitivity of PCRT.1.1 This practice describes a general procedure for using the process compensated resonance testing (PCRT) via swept sine input method for metallic or non-metallic parts to compare resonance patterns from a sample under test to reference teaching sets of known acceptable and targeted defect samples. The resonance pattern differences can be used to distinguish acceptable parts with normal process variation from parts with targeted material states and defects that will cause performance deficiencies. These material states and defects include, but are not limited to, cracks, voids, porosity, shrink, inclusions, discontinuities, grain and crystalline structure differences, density-related anomalies, heat treatment variations, material elastic property differences, residual stress, and dimensional variations. This practice is intended for use with instruments capable of exciting, measuring, recording, and analyzing multiple whole body, mechanical vibration resonance frequencies in acoustic or ultrasonic frequency ranges, or both.1.2 Units—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

1.1 This standard serves as a guide to existing standards or variations of existing standards that may be applicable to determine specific mechanical properties of materials made with an additive manufacturing process.1.2 As noted in many of these referenced standards, there are several factors that may influence the reported properties, including material, material anisotropy, method of material preparation, porosity, method of specimen preparation, testing environment, specimen alignment and gripping, testing speed, and testing temperature. These factors should be recorded, to the extent that they are known, according to Practice F2971 and the guidelines of the referenced standards.1.3 The following standards are not referred to directly in the guide but also have information that may be useful in the testing of metal test specimens made via additive manufacturing: A370, A1058, B211, B348, B557, B565, B724, B769, E3, E6, E7, E290, E467, E468, E837, E915, E1049,E1823, E1942.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 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.1.6 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 The carbon isotope analysis is designed to be an adjunct to other information in determination of biobased content, specifically the manufacturer’s records. It is also a means of verifying the authenticity of a disputed lot of material which may be manufactured by different means, from different raw materials. FTIR or other chemical analysis means will identify the molecule as being ethanol, but not give indication of the source (that is, fossil carbon versus modern carbon). The carbon isotopes will give both indication of source and the presence of a mixture of sources.4.2 Representative sampling and handling methods are clearly a prerequisite to obtaining accurate results from the radiocarbon composition determination and any other quantitative analytical method.4.3 This guide provides for accurate and complete reporting of the sample collection, handling, chain of custody, sample preparation and treatment that allows any independent party to assess the validity of the reported biobased content of the material.1.1 This guide provides a framework for collecting and handling samples for determination of biobased content of materials by means of the carbon isotope method described in Test Methods D6866. Tests for sampling adequacy based on the standard statistical tools are provided. In addition, reporting of the results, including sampling techniques and handling procedures and chain-of-custody issues are discussed.1.2 This guide is concerned with collecting representative samples within a given material or a lot, not with lot-to-lot variations such as considered in quality control schemes.1.3 Biobased materials often represent sampling problems specific to a given material, such as heterogeneity, and so forth, which require employment of material-specific sampling methods. The use of specialized sampling methods already accepted and validated by industries that manufacture and/or use the biomaterial is encouraged. However, all sampling techniques, especially non-standard techniques developed for specific materials must be reported in sufficient detail to allow critical assessment of the techniques used.1.4 Carbon isotope analysis involves thermal processing in presence of oxidants. Compatibility of any given material with Test Methods D6866 must be assessed. Special attention must be given to materials with potential for explosion hazards, such as peroxides, nitrated compounds, azides, and so forth. Examples of peroxide-forming compounds are ethers, some ketones and a number of other compounds.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 requirements prior to use.Note 1—There is no known ISO equivalent to this standard.

定价: 0元 / 折扣价: 0

在线阅读 收 藏

1.1 This specification covers additive manufacturing of parts manufactured via laser beam powder bed fusion (PBF-LB) processing of Grade 4340 (UNS G43400) used in transportation applications, including automotive applications. Parts made using this processing method require heat treatment to achieve maximum strength and are typically used in applications that require mechanical properties similar to wrought Grade 4340 (UNS G43400) products. Products built to this specification may require additional post-processing in the form of machining, polishing etc. to meet necessary surface finish and dimensional tolerances.1.2 This specification describes the required facility, training, equipment, and processing requirements necessary to support the production of parts with properties and associated quality metrics outlined in a part classification structure.1.3 This specification is intended for the use of purchasers or producers, or both, of PBF-LB Grade 4340 (UNS G43400) parts for defining the requirements based on classification methodology. These requirements shall be agreed upon by the part supplier and purchaser.1.4 Users are advised to use this specification as a basis for obtaining parts that will meet the minimum acceptance requirements established and revised by consensus of committee members.1.5 User requirements considered more stringent may be met by additional requirements in the purchase order.1.6 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.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

5.1 This test method (Part A) utilizes FTIR spectroscopy to determine the percent Refrigerant-114 impurity in uranium hexafluoride. Refrigerant-114 is an example of an impurity gas in uranium hexafluoride.1.1 This test method covers determining the concentrations of refrigerant-114, some other carbon-containing and fluorine-containing compounds, hydrocarbons, and partially or completely substituted halohydrocarbons that may be impurities in uranium hexafluoride when looked for specifically. The two options are outlined for this test method. They are designated as Part A and Part B.1.1.1 To provide instructions for performing Fourier-Transform Infrared (FTIR) spectroscopic analysis for the possible presence of Refrigerant-114 impurity in a gaseous sample of uranium hexafluoride, collected in a “2S” container or equivalent at room temperature. The all gas procedure applies to the analysis of possible Refrigerant-114 impurity in uranium hexafluoride, and to the gas manifold system used for FTIR applications. The pressure and temperatures must be controlled to maintain a gaseous sample. The concentration units are in mole percent. This is Part A.1.2 The method discribed in part B is more efficient because there isn’t matrix effect. FTIR spectroscopy identifies bonds as C-H, C-F, C-Cl. To quantify HCH compounds, these compounds must be known and the standards available to do the calibration.After a screening, if the spectrum is the UF6 spectrum or if the other absorption peaks allow the HCH quantification, this test method can be used to check the compliance of UF6 as specified in Specifications C787 and C996. The limits of detection are in units of mole percent concentration.1.3 Part A pertains to Sections 7-10and Part B pertains to Sections 12-16.1.4 These test options are applicable to the determination of hydrocarbons, chlorocarbons, and partially or completely substituted halohydrocarbons contained as impurities in uranium hexafluoride (UF6). Gases such as carbon tetrafluoride (CF4), which absorb infrared radiation in a region where uranium hexafluoride also absorbs infrared radiation, cannot be analyzed in low concentration via these methods due to spectral overlap/interference.1.5 These test options are quantitative and applicable in the concentration ranges from 0.003 to 0.100 mole percent, depending on the analyte.1.6 These test methods can also be used for the determination of non-metallic fluorides such as silicon tetrafluoride (SiF4), phosphorus pentafluoride (PF5), boron trifluoride (BF3), and hydrofluoric acid (HF), plus metal-containing fluorides such as molybdenum hexafluoride (MoF6). The availability of high quality standards for these gases is necessary for quantitative analysis.1.7 These methods can be extended to other carbon-containing and inorganic gases as long as:1.7.1 There are not any spectral interferences from uranium hexafluoride’s infrared absorbances.1.7.2 There shall be a known calibration or known “K” (value[s]) for these other gases.1.8 The values stated in SI units are to be regarded as the standard.1.9 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.

定价: 0元 / 折扣价: 0

在线阅读 收 藏

5.1 This test method provides a simple quantitative measure of water absorption by coated wood or wood based products.5.2 This test method has demonstrated utility for wood or wood based products ranging in thickness from approximately 6 to 25 mm (1/4 to 1 in.).5.3 Conditioning of substrate, coated sample preparation, application method, dry film thickness, cure conditions, and number of replicate specimens should be agreed upon between the purchaser and the supplier of the coating material.5.4 Such measurements are used as indicators or predictors of the anticipated performance of coated wood or wood based products during exterior exposure. They may be used for developmental evaluation of coatings, substrates, or both. They may also be useful for quality control or monitoring of the production of coated wood and wood based products.1.1 This test method is intended to serve as a means for measurement of liquid water that passes through a wetted paint film, and which is subsequently absorbed and retained by the underlying wood or wood-based substrate. Alternative techniques for the use of the “Cobb Ring” apparatus are described.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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 and health practices and determine the applicability of regulatory limitations prior to use.

定价: 515元 / 折扣价: 438 加购物车

在线阅读 收 藏

1.1 This specification covers additively manufactured cobalt-28 chromium-6 molybdenum alloy components with similar chemical composition to UNS R30075 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 cast or 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 cobalt-28 chromium-6 molybdenum alloy 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 than requirements in Sections 1–22 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–S14.1.5 The values stated in SI units are to be regarded as the standard. Other units are included only for informational purposes.1.6 The chemical composition requirements in this specification for cobalt-28 chromium-6 molybdenum alloy components are similar to Specification F1537 Alloys 1 and 2 for wrought cobalt-28 chromium-6 molybdenum and Specification F75 for cast cobalt-28 chromium-6 molybdenum.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

5.1 PCRT Applications and Capabilities—PCRT PTI examination has been applied successfully to a wide range of parts in manufacturing and maintenance environments. Examples of manufacturing processes, repair processes, and in-service damage mechanisms evaluated with PTI are discussed in 1.1. PCRT has been shown to provide cost effective and accurate PTI-based NDT, process monitoring, and life monitoring in many industries including automotive, aerospace, and power generation. Examples of successful applications currently employed in commercial use include, but are not limited to:(1) Heat treatment operations:(a) Aerospace gas turbine engine components (blades, vanes, disks)(b) Additively manufactured components(c) Steel mechanical components(d) Industrial gas turbine blades(2) Induction hardening and carburization (both case-hardened and through-hardened parts):(a) Gears(b) Ballnuts(3) Hot Isostatic Pressing (HIP):(a) Gas turbine engine components (blades, vanes, disks)(b) Additively manufactured components(4) Shot peening:(a) Steel mechanical components(5) In-service thermal history, aging, creep damage, fatigue:(a) Gas turbine engine components (blades, vanes, disks)(b) Industrial gas turbine blades(c) Aircraft landing gear wheels(6) Maintenance repair/rejuvenation processes:(a) Gas turbine engine components (blades, vanes, disks)(b) Industrial gas turbine blades(c) Aircraft landing gear wheels.5.2 General Approach and Equipment Requirements for PCRT via Swept Sine Input: 5.2.1 PCRT systems comprise hardware and software capable of inducing vibrations, recording the component response to the induced vibrations, and analyzing the data collected. Inputting a swept sine wave into the part has proven to be an effective means of introducing mechanical vibration and can be achieved with a high-quality signal generator coupled with an appropriate active transducer in physical contact with the part. Collection of the part’s resonance response is achieved by recording the signal received by an appropriate passive vibration transducer. The software required to analyze the available data may include a variety of suitable statistical analysis and pattern recognition tools. Measurement accuracy and repeatability are extremely important to the application of PCRT.5.2.2 Hardware Requirements—A swept sine wave signal generator and response measurement system operating over the desired frequency range of the test part are required with accuracy better than 0.002 %. The signal generator should be calibrated to applicable industry standards. Transducers must be operable over same frequency range. Three transducers are typically used; one Drive transducer and two Receive transducers. Transducers typically operate in a dry environment, providing direct contact coupling to the part under examination. However, noncontacting response methods can operate suitably when parts are wet or oil-coated. Other than fixturing and transducer contact, no other contact with the part is allowed as these mechanical forces dampen certain vibrations. For optimal examination, parts should be placed precisely on the transducers (generally, ±0.062 in. (1.6 mm) in each axis provides acceptable results). The examination nest and cabling shall isolate the Drive from Receive signals and ground returns, so as to not produce (mechanical or electrical) cross talk between channels. Excessive external vibration or audible noise, or both, will compromise the measurements.5.3 Constraints and Limitations: 5.3.1 PCRT cannot separate parts based on visually detectable anomalies that do not affect the structural integrity of the part. It may be necessary to provide additional visual inspection of parts to identify these indications.5.3.2 Excessive variation in part geometry or base material properties may limit the sensitivity of PCRT PTI examination.5.3.3 A direct measurement of a single geometric dimension of a region undergoing a material state change, such as the case depth (in centimeters or inches) of an induction hardened region, is generally not possible with PCRT PTI. The frequency changes are dependent on the total volumetric effect of the process that causes the material state change. With accurately trained acceptability limits, however, PCRT PTI is very effective at screening populations of components for acceptable and unacceptable processing.5.3.4 PCRT will only work with stiff objects that provide resonances whose peak quality factor (Q) values are greater than 500. Non-rigid materials or very thin-walled parts will not yield useful Q values.5.3.5 While PCRT can be applied to painted and coated parts in many cases, the presence of some surface coatings such as vibration absorbing materials and heavy oil layers may limit or preclude the application of PCRT.5.3.6 While PCRT PTI examination can be applied to parts over a wide range of temperatures, it cannot be applied to parts that are rapidly changing temperature. The part temperature should be stabilized before collecting resonance data.5.3.7 Misclassified parts in the teaching set, along with the presence of unknown anomalies in the teaching set, can significantly reduce the accuracy and sensitivity of PCRT.1.1 This practice covers a general procedure for using the Process Compensated Resonance Testing (PCRT) via swept sine input method to perform Part-to-Itself (PTI) examination on populations of newly manufactured and in-service parts. PCRT detects resonance pattern differences in metallic and non-metallic parts. Practice E2534 for Defect Detection with PCRT and Practice E3081 for Outlier Screening with PCRT cover the development and application of PCRT sorting modules that inspect a part at a single point in time. These methods use the resonance frequency spectra recorded from test parts and perform different statistical analyses to compare test parts to reference populations. These comparisons include, and must compensate for, the normal geometric, material, and processing variations present in any population of parts. In many applications, however, the user may need to evaluate the effects of a single processing step or in-service load in isolation from other sources of variation. For example, a manufacturer may want to perform process monitoring and control on a heat treatment or hardening process. A maintainer may want to evaluate the effect of service cycles in an engine. A PCRT PTI examination measures the resonance frequency spectrum of a part at two points in time, such as before and after a manufacturing process step, and calculates the change in resonance frequencies to evaluate the effect of the intervening process. Control limits can be set on the frequency change to field a PTI PASS/FAIL inspection capability. The limits may be based on training populations of parts with acceptable and unacceptable levels of change, model predictions of the effects of part changes, or criteria derived from process control practices. Manufacturing processes and in-service loads that can be evaluated with a PCRT PTI inspection include, but are not limited to heat treatment, hot isostatic pressing (HIP), shot peening, induction hardening, carburization, coating, thermal history changes, residual stress changes, creep, plastic deformation, corrosion, and fatigue. This practice is intended for use with instruments capable of exciting, measuring, recording, and analyzing multiple, whole body, mechanical vibration resonance frequencies in acoustic or ultrasonic frequency ranges, or both.1.2 Units—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

1.1 This specification covers additive manufacturing of parts via full-melt laser beam powder bed fusion (PBF-LB) processing of maraging steel alloys. Parts made using this processing method are typically used in applications that require mechanical properties similar to wrought products, either as fabricated or heat treated. Products built to this specification may require additional post-processing in the form of machining, polishing, etc., to meet necessary surface finish and dimensional requirements.1.2 Maraging steel (MS) is a class of precipitation hardened steel, where aging heat treatment is used to form precipitates and, consequently, achieve significantly increased hardness and strength. This specification focuses specifically on 300 grade maraging steel, which corresponds to UNS K93120 and EN1.2709. MS grade 300 has higher concentrations of cobalt and titanium than lower grades.1.3 This specification is intended for the use of purchasers or producers, or both, of additively manufactured maraging steel parts for defining the requirements and ensuring part properties.1.4 Users are advised to use this specification as a basis for obtaining parts that will meet the minimum acceptance requirements established and revised by consensus of committee members.1.5 User requirements considered more stringent may be met by the addition to the purchase order of one or more supplementary requirements, which include, but are not limited to, those listed in Supplementary Requirements in Sections S1 to S3.1.6 The values stated in SI units are to be regarded as standard. All units of measure included in this guide are accepted for use with the SI.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 cumene (isopropylbenzene) manufactured via a zeolite catalyst process. Cumene shall conform to the following requirements: purity weight percent, alpha-methylstrene, benzene, cumene hydroperoxide, diisopropylbenzenes, ethylbenzene, i-butylbenzene, n-butylbenzene, s- butylbenzene, t- butylbenzene, phenols, n-propylbenzene, sulfur, toluene, total butylbenzenes, total cymenes, total non-aromatics, total GC unknowns, bromine index, appearance, and color.1.1 This specification covers cumene (isopropylbenzene) manufactured using a zeolite catalyst process.1.2 The following applies to all specified limits in this specification: for purposes of determining conformance with this specification, an observed value or a calculated value shall be rounded off “to the nearest unit” in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E29.1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 Consult current OSHA Regulations and Supplier’s Safety Data Sheets, and local regulations for all materials used in this specification.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: 515元 / 折扣价: 438 加购物车

在线阅读 收 藏

1.1 This specification covers additive manufacturing of parts manufactured via laser beam powder bed fusion (PBF-LB) processing of niobium-hafnium alloy used in spaceflight applications. Parts made using this processing method are typically used in applications that require mechanical properties like wrought products. Products built to this specification may require additional post-processing in the form of machining, polishing etc. to meet necessary surface finish and dimensional tolerances.1.2 This specification is intended for the use of purchasers or producers, or both, of PBF-LB R04295 parts for defining the requirements based on classification methodology. These requirements shall be agreed upon by the part supplier and purchaser.1.3 Users are advised to use this specification as a basis for obtaining parts that will meet the minimum acceptance requirements established and revised by consensus of committee members.1.4 User requirements considered more stringent may be met by the addition to the purchase order.1.5 Units—The values stated in SI units are to be regarded as the standard. Other units are included only for informational purposes.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, 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: 590元 / 折扣价: 502 加购物车

在线阅读 收 藏

3.1 The tendency of a jet fuel to resist the formation of deposits at elevated temperature is indicative of its oxidative thermal stability. This practice provides a technique for the simultaneous determination of deposit formation and oxygen consumption during the thermal oxidation of jet fuels and other hydrocarbon liquids. The practice can be used to evaluate the thermal stability of fuels and to determine the efficacy of additives in inhibiting deposition or slowing oxidation, or both. A test temperature of 140 °C and run length up to 16 h has been found to be effective for the relative evaluation of fuels and fuel additives. This practice has also been employed for other hydrocarbon liquids, such as gasoline and diesel fuels, but additional safety issues may need to be addressed by the user.1.1 This laboratory practice covers the quantitative determination of surface deposits produced during the thermal oxidation of gas turbine fuels by monitoring the oscillation frequency of a quartz crystal during thermal exposure. In this practice, “thermal oxidative stability” refers to the tendency of a fuel to resist surface deposit formation during heating.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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
25 条记录,每页 15 条,当前第 1 / 2 页 第一页 | 上一页 | 下一页 | 最末页  |     转到第   页