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3.1 This test method determines relative hydration resistance of magnesia grain.3.2 This test method is used in industry to evaluate grain samples and is used for specification purposes in some cases.3.3 Care must be taken in interpreting the data.1.1 This test method covers the measurement of the relative resistance of magnesia grain to hydration.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.

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ASTM E112-13(2021) Standard Test Methods for Determining Average Grain Size Active 发布日期 :  1970-01-01 实施日期 : 

4.1 These test methods cover procedures for estimating and rules for expressing the average grain size of all metals consisting entirely, or principally, of a single phase. The grain size of specimens with two phases, or a phase and a constituent, can be measured using a combination of two methods, a measurement of the volume fraction of the phase and an intercept or planimetric count (see Section 17). The test methods may also be used for any structures having appearances similar to those of the metallic structures shown in the comparison charts. The three basic procedures for grain size estimation are:4.1.1 Comparison Procedure—The comparison procedure does not require counting of either grains, intercepts, or intersections but, as the name suggests, involves comparison of the grain structure to a series of graded images, either in the form of a wall chart, clear plastic overlays, or an eyepiece reticle. There appears to be a general bias in that comparison grain size ratings claim that the grain size is somewhat coarser (1/2 to 1 G number lower) than it actually is (see X1.3.5). Repeatability and reproducibility of comparison chart ratings are generally ±1 grain size number.4.1.2 Planimetric Procedure—The planimetric method involves an actual count of the number of grains within a known area. The number of grains per unit area, NA , is used to determine the ASTM grain size number, G. The precision of the method is a function of the number of grains counted. A precision of ±0.25 grain size units can be attained with a reasonable amount of effort. Results are free of bias and repeatability and reproducibility are less than ±0.5 grain size units. An accurate count does require marking off of the grains as they are counted.4.1.3 Intercept Procedure—The intercept method involves an actual count of the number of grains intercepted by a test line or the number of grain boundary intersections with a test line, per unit length of test line, used to calculate the mean lineal intercept length, ℓ. ℓ is used to determine the ASTM grain size number, G. The precision of the method is a function of the number of intercepts or intersections counted. A precision of better than ±0.25 grain size units can be attained with a reasonable amount of effort. Results are free of bias; repeatability and reproducibility are less than ±0.5 grain size units. Because an accurate count can be made without need of marking off intercepts or intersections, the intercept method is faster than the planimetric method for the same level of precision.4.2 For specimens consisting of equiaxed grains, the method of comparing the specimen with a standard chart is most convenient and is sufficiently accurate for most commercial purposes. For higher degrees of accuracy in determining average grain size, the intercept or planimetric procedures may be used. The intercept procedure is particularly useful for structures consisting of elongated grains (see Section 16).4.3 In case of dispute, the planimetric procedure shall be the referee procedure in all cases.4.4 No attempt should be made to estimate the average grain size of heavily cold-worked material. Partially recrystallized wrought alloys and lightly to moderately cold-worked material may be considered as consisting of non-equiaxed grains, if a grain size measurement is necessary.4.5 Individual grain measurements should not be made based on the standard comparison charts. These charts were constructed to reflect the typical log-normal distribution of grain sizes that result when a plane is passed through a three-dimensional array of grains. Because they show a distribution of grain dimensions, ranging from very small to very large, depending on the relationship of the planar section and the three-dimensional array of grains, the charts are not applicable to measurement of individual grains.1.1 These test methods cover the measurement of average grain size and include the comparison procedure, the planimetric (or Jeffries) procedure, and the intercept procedures. These test methods may also be applied to nonmetallic materials with structures having appearances similar to those of the metallic structures shown in the comparison charts. These test methods apply chiefly to single phase grain structures but they can be applied to determine the average size of a particular type of grain structure in a multiphase or multiconstituent specimen.1.2 These test methods are used to determine the average grain size of specimens with a unimodal distribution of grain areas, diameters, or intercept lengths. These distributions are approximately log normal. These test methods do not cover methods to characterize the nature of these distributions. Characterization of grain size in specimens with duplex grain size distributions is described in Test Methods E1181. Measurement of individual, very coarse grains in a fine grained matrix is described in Test Methods E930.1.3 These test methods deal only with determination of planar grain size, that is, characterization of the two-dimensional grain sections revealed by the sectioning plane. Determination of spatial grain size, that is, measurement of the size of the three-dimensional grains in the specimen volume, is beyond the scope of these test methods.1.4 These test methods describe techniques performed manually using either a standard series of graded chart images for the comparison method or simple templates for the manual counting methods. Utilization of semi-automatic digitizing tablets or automatic image analyzers to measure grain size is described in Test Methods E1382.1.5 These test methods deal only with the recommended test methods and nothing in them should be construed as defining or establishing limits of acceptability or fitness of purpose of the materials tested.1.6 The measured values are stated in SI units, which are regarded as standard. Equivalent inch-pound values, when listed, are in parentheses and may be approximate.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 The paragraphs appear in the following order:Section Number  1Referenced Documents  2Terminology  3  4Generalities of Application  5Sampling  6Test Specimens  7Calibration  8Preparation of Photomicrographs  9Comparison Procedure 10Planimetric (Jeffries) Procedure 11General Intercept Procedures 12Heyn Linear Intercept Procedure 13Circular Intercept Procedures 14Hilliard Single-Circle Procedure  14.2Abrams Three-Circle Procedure  14.3Statistical Analysis 15Specimens with Non-equiaxed Grain Shapes 16Specimens Containing Two or More Phases or Constituents 17Report 18Precision and Bias 19Keywords 20Annexes:   Basis of ASTM Grain Size Numbers Annex A1 Equations for Conversions Among Various Grain Size Measurements Annex A2 Austenite Grain Size, Ferritic and Austenitic Steels Annex A3 Fracture Grain Size Method Annex A4 Requirements for Wrought Copper and Copper-Base Alloys Annex A5 Application to Special Situations Annex A6Appendixes:   Results of Interlaboratory Grain Size Determinations Appendix X1 Referenced Adjuncts Appendix X21.9 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.

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5.1 The shear strength of a specimen depends on the method of shearing, soil type, vertical consolidation stress, time of consolidation, rate of strain, and prior stress history of the soil.5.2 In this test, the shear strength is measured under constant volume conditions that are equivalent to undrained conditions for a saturated specimen; hence, the test is applicable to field conditions wherein soils have fully consolidated under one set of stresses, and then are subjected to changes in stress without time for further drainage to take place.5.3 The constant volume (undrained) strength is a function of stress conditions. In this test method, the strength is measured under plane strain conditions and the principle stresses continuously rotate due to the application of shear stress. This simple shear stress condition occurs in many field situations including zones below a long embankment and around axially loaded piles.5.4 The state of stress within the simple shear specimen is not sufficiently defined nor uniform enough to allow rigorous interpretation of the results. Expressing the data in terms of the shear stress and vertical effective stress on the horizontal plane is useful for engineering purposes, but should not be confused with the effective stress parameters derived from other shear tests having better defined states of stress.5.5 The values of the secant shear modulus can be used to estimate the initial settlements of embankments built on saturated cohesive soils due to undrained shear deformations.5.6 The data and the rate of consolidation from the consolidation portion of this test are comparable to results obtained using Test Methods D2435 provided that the more rigorous consolidation procedure of Test Methods D2435 is followed.5.6.1 When using wire reinforced membranes the vertical displacements measured from Test Methods D2435 are somewhat smaller than for the direct simple shear test because the direct simple shear (DSS) specimen's lateral confinement is less rigid.5.6.2 The estimated preconsolidation pressure is comparable provided the specimen is loaded sufficiently into the normally consolidated range.1.1 This test method defines equipment specifications and testing procedures for the measurement of constant volume strength and stress-strain characteristics of cohesive soils after one-dimensional consolidation using a constant rate of simple shear deformation mode of loading. The constant volume condition is equivalent to the undrained condition for saturated specimens.1.2 This test method is written specifically for devices that test rectangular parallelepiped or cylindrical specimens. Other more general devices, such as the torsional shear hollow cylinder, may be used to perform consolidated constant volume simple shear tests but are beyond the scope of this test method.1.3 This test method is applicable to testing intact, laboratory reconstituted, and compacted soils, however, it does not include specific guidance for reconstituting or compacting test specimens.1.4 It shall be the responsibility of the agency requesting this test to specify the magnitude of the vertical consolidation stress prior to constant volume shear and, when appropriate, the maximum vertical consolidation stress, which will result in an overconsolidated specimen.1.5 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method.1.5.1 In the engineering profession it is customary practice to use, interchangeably, units representing both mass and force, unless dynamic calculations (F=Ma) are involved. This implicitly combines two separate systems of units, that is, the absolute system and the gravimetric system. It is scientifically undesirable to combine two separate systems within a single standard. This test method has been written using SI units; however, inch-pound conversions are given in the gravimetric system, where the pound (lbf) represents a unit of force (weight). The use of balances or scales recording pounds of mass (lbm), or the recording of density in lb/ft3 should not be regarded as nonconformance with this test method.1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.6.1 The procedures used to specify how data are collected/recorded or calculated in this test standard are regarded as the industry standard. In addition, they are representative of the significant digits that should generally be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this test standard to consider significant digits used in analysis methods for engineering design.1.6.2 Measurements made to more significant digits or better sensitivity than specified in this standard shall not be regarded a nonconformance with this 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, 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.

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5.1 Duplex grain size may occur in some metals and alloys as a result of their thermomechanical processing history. For comparison of mechanical properties with metallurgical features, or for specification purposes, it may be important to be able to characterize grain size in such materials. Assigning an average grain size value to a duplex grain size specimen does not adequately characterize the appearance of that specimen, and may even misrepresent its appearance. For example, averaging two distinctly different grain sizes may result in reporting a size that does not actually exist anywhere in the specimen.5.2 These test methods may be applied to specimens or products containing randomly intermingled grains of two or more significantly different sizes (henceforth referred to as random duplex grain size). Examples of random duplex grain sizes include: isolated coarse grains in a matrix of much finer grains, extremely wide distributions of grain sizes, and bimodal distributions of grain size.5.3 These test methods may also be applied to specimens or products containing grains of two or more significantly different sizes, but distributed in topologically varying patterns (henceforth referred to as topological duplex grain sizes). Examples of topological duplex grain sizes include: systematic variation of grain size across the section of a product, necklace structures, banded structures, and germinative grain growth in selected areas of critical strain.5.4 These test methods may be applied to specimens or products regardless of their state of recrystallization.5.5 Because these test methods describe deviations from a single, log-normal distribution of grain sizes, and characterize patterns of variation in grain size, the total specimen cross-section must be evaluated.5.6 These test methods are limited to duplex grain sizes as identifiable within a single polished and etched metallurgical specimen. If duplex grain size is suspected in a product too large to be polished and etched as a single specimen, macroetching should be considered as a first step in evaluation. The entire macroetched cross-section should be used as a basis for estimating area fractions occupied by distinct grain sizes, if possible. If microscopic examination is subsequently necessary, individual specimens must be taken to allow estimation of area fractions for the entire product cross-section, and to allow determination of grain sizes representing the entire cross-section as well.5.7 These test methods are intended to be applied to duplex grain sizes. Duplex grain structures (for example, multiphase alloys) are not necessarily duplex in grain size, and as such are not the subject of these methods. However, the test methods described here for area fraction estimation may be of use in describing duplex grain structures.1.1 These test methods provide simple guidelines for deciding whether a duplex grain size exists. The test methods separate duplex grain sizes into one of two distinct classes, then into specific types within those classes, and provide systems for grain size characterization of each type.1.2 Units—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 standard may involve hazardous materials, operations, and equipment. 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.

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This specification deals with continuous grain flow carbon and alloy steel crankshaft forgings intended for medium speed diesel and natural gas engines. The steel used in the manufacture of the forgings is required to be vacuum degassed. Heat treatment, which may be done either before or after rough machining, shall consist of normalizing followed by tempering at a subcritical temperature, or austenitizing, liquid quenching and subcritical tempering. Charpy impact and tensile tests, which shall be performed at a frequency of one test per heat treatment load, shall be used to evaluate tensile strength, yield strength, elongation, reduction of area, and Brinell hardness requirements of forgings. Chemical composition requirements shall also be examined by heat analysis. Grain size tests and non-destructive magnetic particle examinations shall be conducted as well. When required by the purchaser, crankshafts may be surface hardened in designated areas for the purposes of enhanced wear resistance and fatigue strength.1.1 This specification covers continuous grain flow forged carbon and alloy steel crankshafts for medium speed diesel and natural gas engines.1.2 The steel used in the manufacture of the forgings is required to be vacuum degassed.1.3 The choice of steel composition grade for a given strength class is normally made by the forging supplier, unless otherwise specified by the purchaser.1.4 Provision is made for treatment of designated surfaces of the crankshaft to provide enhanced fatigue strength, or wear resistance, or both.1.5 Except as specifically required in this specification, all provisions of Specification A788/A788M apply.1.6 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound units.1.7 The values stated in either inch-pound units or SI (metric) units are to be regarded separately as standard. Within the text and tables 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.1.8 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.

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This test method covers the procedures for the standard practice of performing magnetic particle examination of continuous grain flow crankshaft forgings intended for medium speed diesel engines. Crankshafts shall be divided into four zones of decreasing operational stress, each of which have been designated its own set of acceptance criteria. Zone 1, which consists of the major critical areas, includes the crankpin journals, main bearing journals, and oil holes. Zone 2, which consists of the minor critical areas, includes the balance of the fillet radii of the crankpin and main bearing journals not included in Zone 1. Zone 3, which comprises the journal running surfaces, includes the remainder of the crankpin and main bearing journal surfaces not covered by Zones 1 and 2. Finally, Zone 4 comprises all other remaining areas, including the crankpin web surfaces, and flange faces and periphery. Dimpling technique may be used to remove unwanted visual or magnetic particle indications.1.1 This specification covers the magnetic particle examination of forged continuous grain flow (CGF) crankshafts intended for medium speed diesel engines.1.2 For the purpose of magnetic particle indication assessment, the crankshaft is divided into four zones of decreasing operational stress. Acceptance criteria have been set for each zone.1.3 The engines to which these crankshafts are fitted are commonly used for diesel electric locomotives, marine propulsion, and power generation. Engines fueled by natural gas also fall into this medium speed category.1.4 Specification A983/A983M is a product specification that covers the manufacture of CGF crankshafts.1.5 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.1.6 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.

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5.1 This practice provides a way to estimate the average grain size of polycrystalline materials. It is based on EBSD measurements of crystallographic orientation which are inherently quantitative in nature. This method has specific advantage over traditional optical grain size measurements in some materials, where it is difficult to find appropriate metallographic preparation procedures to adequately delineate grain boundaries.1.1 This practice is used to determine grain size from measurements of grain areas from automated electron backscatter diffraction (EBSD) scans of polycrystalline materials.1.2 The intent of this practice is to standardize operation of an automated EBSD instrument to measure ASTM G directly from crystal orientation. The guidelines and caveats of E112 apply here, but the focus of this standard is on EBSD practice.1.3 This practice is only applicable to fully recrystallized materials.1.4 This practice is applicable to any crystalline material which produces EBSD patterns of sufficient quality that a high percentage of the patterns can be reliably indexed using automated indexing software.1.5 The practice is applicable to any type of grain structure or grain size distribution.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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, 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.

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5.1 The microstructure and grain growth of cemented tungsten carbides affect the material's mechanical and physical properties. The grain size and distribution will affect the material's wear resistance and fracture toughness. Abnormally large grains as compared to the background may introduce an area of weakness in a sintered part.5.2 This test method may be used in acceptance testing of cemented tungsten carbide materials or the tungsten carbide powder used in their manufacture. The specified grain size used for the E-Rating is to be agreed upon between purchaser and supplier.1.1 This test method describes a procedure for measuring abnormally large grains and the frequency of those grains in cemented tungsten carbides (hardmetals).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.

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4.1 The test method is designed to measure the force required to crack the grain of leather by steady hydraulic pressure on a diaphragm of definite diameter applied to the flesh side of the specimen to form a sphere. The cracking of the grain is a result of failure under elongation or stretch. The elongation or stretch of the leather can be measured at different loads or at the failure of the grain to determine if the stress leather will withstand under lasting conditions. Cuts, scratches, and other defects will cause considerable variation in the results by concentration of the applied force to the weak points. This test method is excellent for manufacturing control, specification acceptance, and service evaluation in the lasting property of leather. This test method may not apply when the conditions of the test employed differ widely from those specified in the test method.1.1 This test method covers the determination of the resistance of leather to grain cracking and for measuring the extension of the leather. It is limited to light leathers such as shoe uppers, garment, gloves, and upholstery. This test method does not apply to wet blue or wet white.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.

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The apparent size and distribution of tungsten carbide grains in cemented carbides affects the material’wear resistance and fracture. For a given chemical composition, an increase in the average grain size will result in increased toughness and decreased wear resistance. This practice illustrates representative micro-structures for a wide range of tungsten carbide-cobalt grades. This is not intended to be used as a specification for carbide grades; producers and users may use the micrographs and the grain size chart as a guide in developing their own specifications.1.1 This practice for the visual comparison and classification of the apparent grain size and distribution of cemented tungsten carbides is limited to cemented tungsten carbides that contain approximately 6, 10, and 18 % cobalt.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.

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5.1 The grain stability of calcined petroleum coke determines the resistance to breakdown of + 4 mm particles used in the manufacture of carbon anodes for use in the reduction process of aluminum.5.2 Calcined petroleum cokes have to be relatively easy to grind for fines production but strong enough to withstand forming pressures and thermal stresses occurring when the anodes are used in the reduction process.1.1 This test method covers a laboratory vibration mill method for the determination of the grain stability of calcined petroleum coke for the manufacture of carbon products used in the smelting of aluminum. Calcined petroleum coke with poor mechanical strength may become degraded during mixing. Poor grain stability will affect the grain size and may result in poor quality of baked blocks.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 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.

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4.1 If not properly qualified, chemicals and chemical processes can attack metals used during aircraft maintenance and production. It is important to qualify only processes and chemical formulas that do not have any deleterious effects on aircraft metallic skins, fittings, components, and structures. This test procedure is used to detect and measure intergranular attack or pitting depth caused by aircraft maintenance chemical processes, hence, this test procedure is useful in selecting a process that will not cause intergranular attack or end grain pitting on aircraft alloys.4.2 The purpose of this practice is to aid in the qualification or process conformance testing or production of maintenance chemicals for use on aircraft.4.2.1 Actual aircraft processes in the production environment shall give the most representative results; however, the test results cannot be completely evaluated with respect to ambient conditions which normally vary from day to day. Additionally, when testing chemicals requiring dilutions, water quality and composition can play a role in the corrosion rates and mechanism affecting the results.4.2.2 Some examples of maintenance and production chemicals include: organic solvents, paint strippers, cleaners, deoxidizers, water-based or semi-aqueous cleaners, or etching solutions and chemical milling solutions.1.1 This practice covers the procedures for testing and measuring intergranular attack (IGA) and end grain pitting on aircraft metals and alloys caused by maintenance or production chemicals.1.2 The standard does not purport to address all qualification testing parameters, methods, critical testing, or criteria for aircraft production or maintenance chemical qualifications. Specific requirements and acceptance testing along with associated acceptance criteria shall be found where applicable in procurement specifications, materials specifications, appropriate process specifications, or previously agreed upon specifications.1.3 Units—The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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.

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4.1 The presence of large grains has been correlated with anomalous mechanical behavior in, for example, crack initiation, crack propagation, and fatigue. Thus there is engineering justification for reporting the ALA grain size.4.2 These methods shall only be used with the presence of outlier coarse grains, 3 or more ASTM grain size numbers larger than the rest of the microstructure and comprising 5 % or less of the specimen area. A typical example is shown in Annex A1 as Fig. A1.1.4.3 These methods shall not be used for the determination of average grain size, which is treated in Test Methods E112. Examples of microstructures that do not qualify for ALA treatment are shown in Annex A1 as Fig. A1.2, Fig. A1.3, and Fig. A1.4.4.4 These methods may be applied in the characterization of duplex grain sizes, as instructed in the procedures for Test Methods E1181.1.1 These test methods describe simple manual procedures for measuring the size of the largest grain cross-section observed on a metallographically prepared plane section.1.2 These test methods shall only be valid for microstructures containing outlier coarse grains, where their population is too sparse for grain size determination by Test Methods E112.1.3 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

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This specification covers the detailed requirements for specified grades of flat-rolled, grain-oriented, fully processed low-carbon silicon-iron electrical steels, whose low core loss and high permeability in the direction of rolling have been achieved by appropriate metallurgical processing. These steels are primarily used in transformer cores operating at moderate to high magnetic flux densities at commercial power frequencies. These steels may be acquired in any of four conditions a.) conventional grain-oriented tested at 15 kG (1.5 T), b.) conventional grain-oriented tested at 17 kG (1.7 T), c.) high-permeability grain-oriented tested at 17 kG (1.7 T) and d.) laser-scribed high-permeability grain-oriented tested at 17 kG (1.7 T). These steels can be purchased in a number of combinations of material form and surface type or treatment. This specification explains in detail, the available forms, thicknesses and magnetic performance.1.1 This specification covers the detailed requirements to which the specified grades of flat-rolled, grain-oriented, fully processed electrical steels shall conform. These steels are used primarily in transformer cores operating at moderate to high magnetic flux densities at commercial power frequencies (50 and 60 Hz).1.2 These grain-oriented electrical steels are low-carbon, silicon-iron alloys with a silicon content of approximately 3.2 % in which low core loss and high permeability in the direction of rolling have been achieved by appropriate metallurgical processing.1.3 The electrical-steel grades described in this specification include (1) conventional grain-oriented electrical steel tested at 1.5 T (15 kG) in accordance with Test Method A343/A343M, (2) conventional grain-oriented electrical steel tested at 1.7 T (17 kG) in accordance with Test Method A343/A343M, (3) high-permeability grain-oriented electrical steel tested at 1.7 T (17 kG) in accordance with Test Method A343/A343M, and (4) laser-scribed high-permeability grain-oriented electrical steel tested at 1.7 T (17 kG) in accordance with Test Methods A804/A804M.1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to customary (cgs-emu and inch-pound) units which are provided for information only and are not considered 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 and health 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

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