ASTM B215-2015 Standard Practices for Sampling Metal Powders《用于金属粉末取样的标准实施规程》.pdf

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1、Designation: B215 10B215 15Standard Practices forSampling Metal Powders1This standard is issued under the fixed designation B215; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses in

2、dicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 These practices cover sampling methods used to collect a small quantity

3、of metal powder that is as representative of theentire starting material as possible, and details the procedures that are recommended for reducing this quantity into smaller testportions on which chemical, physical, and mechanical property data may be determined.1.2 These practices describe two proc

4、edures for obtaining samples of metal powders for subsequent testing:Several samplingpractices are described, depending on their applicability to the conditions of storage and transport of the sampled powders:1.2.1 Practice A1A (Described in Section 6)For powders Applicable to sampling moving powder

5、s, as when beingtransferred from blenders or storage tanks.one container to another or to a process stream; or when falling from a conveyor; or ina moving process stream. This is the preferred practice for obtaining the several increments that are combined to form the grosssample.1.2.2 Practice B1B

6、(Described in Section 7)For powders already packaged in containers.Applicable to sampling powdersthat have already been packaged for transport, as in a bag or drum. A hollow tubular slot sampler is the recommended way tosample these packaged powders to obtain the increments (7.1.1). Alternatively, w

7、hen other methods are not possible or available,a procedure specified here (7.1.2) may be used to randomly scoop samples from the powder, using a scoop of specified materialand configuration.1.2.3 Practice 2 (Described in Section 8)Applicable to obtaining test portions from the composite sample. For

8、 largerquantities of powder, a chute splitter is generally used, while a spinning riffler is used for smaller quantities.1.3 These practices apply to particulate materials or mixtures of particulates with particle sizes generally less than onemillimetre and include mixtures containing lubricant, wit

9、h or without other non-metallic additives, that are ready for compacting.1.4 These practices do not cover the sampling of flake powders or pastes. For procedures on the sampling and testing of flakemetal powders and pastes, refer to Test Methods D480.1.5 The values stated in inch-pound units are to

10、be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityo

11、f the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B243 Terminology of Powder MetallurgyD480 Test Methods for Sampling and Testing of Flaked Aluminum Powders

12、 and Pastes3. Terminology3.1 DefinitionsDefinitions of powder metallurgy terms can be found in Terminology B243.Additional descriptive informationis available in the Related Materials section of Vol 02.05 of the Annual Book of ASTM Standards.1 These practices are under the jurisdiction of ASTM Commi

13、ttee B09 on Metal Powders and Metal Powder Products and are the direct responsibility of SubcommitteeB09.02 on Base Metal Powders.Current edition approved Dec. 1, 2010Oct. 1, 2015. Published March 2011October 2015. Originally approved in 1946. Last previous edition approved in 20082010 asB215 08.B21

14、5 10. DOI: 10.1520/B0215-10.10.1520/B0215-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is

15、 not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropr

16、iate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States

17、13.2 Definitions of Terms Specific to This Standard:3.2.1 See Fig. 1. for the terms hereinafter defined.3.2.2 composite sampleblended entire gross sample.3.2.3 incrementquantity of powder obtained by a sampling device at one time from a single lot.larger quantity of powder.3.2.4 gross sampletotal qu

18、antity of powder adequate for the tests to be performed, intended purpose(s), consisting of all theincrements taken from a single bined.3.2.5 test samplequantity of powder taken from the composite sample for determining a single property or for preparing thetest pieces. It should normally be taken b

19、y splitting the composite sample.3.2.5 test portiondefined quantity of powder (generally taken from the test samplecomposite sample) on which the test isperformed, or from which a test pieces arepiece is produced.4. Significance and Use4.1 Specifications and test methods for metal powders and metal

20、powder products require the sampling, testing, andperformance evaluation of small samples taken from large quantities of powder. The sampling procedure is equally as importantas the testing and evaluation; the sampling methods used must include every precaution to ensure that the samples obtained wi

21、llshow the true nature and condition of the large powder quantity that they represent.4.2 The primary objective of any sampling procedure is to obtain a small quantity of material that is truly representative of thelarger amount from which it is taken, a condition that is readily comprehended but di

22、fficult to define, quantify, and prove. Certaincriteria are desirable to meet this condition:34.2.1 Every sampling increment should have a non-zero probability of being selected.4.2.2 All increments should have an equal probability of being selected.3 Pierre M. Gy, Sampling of Heterogeneous and Dyna

23、mic Material Systems. Elsevier: New York, NY, 1992FIG. 1 Scheme of SamplingB215 1524.2.3 The sampling procedure should not alter the material (for example, by changing the particle size or chemicalcomposition).4.3 Sampling a moving powder helps to satisfy these criteria; therefore, Practice 1Ashould

24、 be used whenever possible to obtainthe composite sample. Similarly, Practice 2 should be used to obtain the test portions; use of a spinning riffler is preferred whenpossible and practicable.4.4 Although not always meeting all the criteria of 4.2.1 4.2.3, the other sampling practices described in t

25、his standard arebased on time-proven experience in the PM industry in sampling granular metal powders. These practices have been shown toproduce samples that give reliable and representative evaluation data.4.5 Since many tests are performed using very small amounts of powder, powder meant to repres

26、ent much larger quantities, itis most important that the test portions be obtained in a standardized manner. The practices described here take into account thepossibility of segregation of the metal powder during and after filling of containers.PRACTICE AFOR POWDERS BEING TRANSFERRED FROM BLENDERS O

27、R STORAGE TANKS4.6 Sample quantities of metal powder are used for chemical analysis and to determine the physical characteristics of thepowder. These data are used for production control and quality inspection of finished lots.4.7 Green compacts produced from powder samples are used to evaluate the

28、compactability properties of metal powders,information that is important to the use of these powders in the manufacture of PM bearings and structural parts.4.8 Test specimens produced from metal powder samples are compacted and sintered and used to measure physical andmechanical properties of solid

29、PM materials. The data obtained are included in PM material specifications to assist with materialselection for PM applications.4.9 Solid PM articlesstructural parts, bearings, etc.are produced from metal powder samples to evaluate powderperformance in the manufacturing and end use of such articles.

30、5. Apparatus5.1 Rectangular Receptacle, capable of being moved completely across thea stream of flowing powder at a constant speed andhaving a length and width greater than the stream of powder. It must be large enough so that no overflow of powder occurs whencollecting the sample.5.2 Small Blender.

31、 BlenderOf sufficient capacity to blend the entire gross sample, consisting of all the increments combined.5.3 Commercial Sampling DeviceMany powder transfer systems are closed for dust control, but there are commercial devicesavailable that can be inserted into a section of a pipe to collect powder

32、 increments while maintaining the flowing stream.5.4 Sample Splitter, Powder SamplerA slot or tube sampler with an auger point that can be screwed to the bottom of a filledcontainer and is designed to collect powder at one (single-level) or more (multi-level) depths, see Fig. 2 and Fig. 3.5.5 Powder

33、 ScoopA non-magnetic stainless steel scoop with a sharp edge and high sides, of a size and capacity capable ofobtaining the desired powder increment. See Fig. 4.5.6 Chute SplitterOf sufficient size and capacity to split the required amount of powder into two approximately-equalportions, see Fig. 5.

34、Several different sizes of splitter may be necessary throughout the sampling process, depending on the samplesize at each step. The size of the chute openings should be at least three times the largest particle size to be sampled, and the chuteangle should be at least 45. The smallest of the chute s

35、plitters are often referred to as “micro splitters.”5.7 Charging PanA pan that is the same width as the chute splitter and large enough to contain the sample to be split.5.8 Spinning Riffler, RifflerOf sufficient size and capacity to split the required amount of powder into at least eightapproximate

36、ly-equal portions, see Fig. 36. Several different sizes of riffler may be necessary throughout the sampling process,depending on the sample size at each step. The smallest of these are often referred to as “micro rifflers.”PART 1OBTAINING THE COMPOSITE SAMPLE6. ProcedurePactice 1ASampling a Moving P

37、owder6.1 The preferred method for sampling powders is always when the powder is in motion, as, for example, when beingtransferred from a blender or a storage tank, or falling from a conveyor, or in a moving process stream (pipeline).6.2 Equal powder increments should be taken at random intervals ove

38、r the life of the flow.6.3 The number of increments that make up the gross sample should be agreed upon between the parties concerned.B215 153FIG. 42 Keystone SamplerMulti-Level Slot Sampler with AugerPoint(Keystone Sampler)FIG. 3 Spinning Riffler-SchematicSingle-Level Tube Sampler with Auger Point

39、(Full View and Close-Up of Point) SchematicB215 1546.4 Pass the rectangular receptacle at a constant speed completely through the stream of flowing powder, starting immediatelyupon flow. Repeat at random intervals until the agreed-upon number of increments is obtained, taking the last increment near

40、 theend of the flow.6.5 Alternatively, use a commercial sampling device to collect the agreed-upon number of increments, starting immediatelyupon flow, and taking the last increment near the end of the flow.6.6 Pass the rectangular receptacle at a constant speed completely through the stream of flow

41、ing powder. If the entire contentsof one lot of powder are being packed in a single container, take increments when the container is 14 , 12 , and 34 filled. If severalFIG. 54 Alternative Sampling DeviceStainless Steel Scoop for Sampling Metal PowderFIG. 25 Sample SplitterChute Splitter SchematicB21

42、5 155containers are to be filled by one lot of powder, take the first increment when the first container is 12 filled, the second incrementin the middle of the run, and the third increment near the end of the run. Additional increments may be agreed upon by the partiesconcerned. The total amount fro

43、m all increments shall be adequate for the tests or evaluations to be performed. CombineNOTE 1To investigate within-lot and sampling variability, individual increments may be tested rather than being combined to form a compositesample. the increments to obtain the gross sample.NOTE 1To investigate w

44、ithin-lot variability, individual increments may be tested rather than being combined to form a composite sample.6.7 Combine the increments to form the gross sample.6.8 Blend the gross sample in a small blender for 10 to 15 revolutions to form ato form the composite sample.6.3 Pass the composite sam

45、ple through a sample splitter or spinning riffler to obtain the test samples.6.4 Obtain the test portion from the test sample by use of a sample splitter, or a sample spinning riffler.NOTE 1Reprinted with permission from the International Journal ofPowder Metallurgy, 1997, Volume 33, Number 8, Page

46、40, Figure 6,APMI International, 105 College Road East, Princeton, New Jersey, USA.FIG. 6 Spinning Riffler SchematicB215 1567. Frequency of Increments7.1 Take at least three increments for each lot of powder. The actual number depends on the size of the lot and the powderinvolved and shall be agreed

47、 upon by the parties involved.PRACTICE BFOR POWDERS ALREADY PACKAGED IN CONTAINERS8. Apparatus8.1 Keystone Sampler, see Fig. 4; or other appropriate sampling devicesee Fig. 5.8.2 Small Blender.8.3 Sample Splitter, see Fig. 2.8.4 Spinning Riffler, see Fig. 3.7. Procedure Practice 1BSampling a Station

48、ary Powder7.1 Obtain Although sampling a powder increment from the container using either of the following devices:moving powder isalways preferred, it is not always possible to do so with powders that have already been packaged for shipment (for example, indrums, pails, or bags). Such stationary po

49、wders must then be sampled using either a tube (slot) sampler or a simple scoop, asspecified in the following sections.7.1.1 Keystone Sampling a Stationary Powder Using a Slot or Tube SamplerInsert the Keystone sampler, in the closedposition,Using a hollow tubular multi-level slot sampler (Fig. 2 into the powder at a point about 70 % of the distance from thecenter of the cross-section to the periphery and straight down ) to remove powder from several depths of the container is therecommended way to sample packaged powder. A