Designation:A 684/A684M –86(Reapproved 1998)
Standard Specification for
Steel,Strip,High-Carbon,Cold-Rolled 1
This standard is issued under the fixed designation A 684/A684M;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon (e )indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.
1.Scope
1.1This specification covers cold-rolled,high-carbon strip.It is furnished in the following types as specified:
1.1.1Soft spheroidized annealed high-carbon steel is in-tended for applications requiring maximum cold forming.It is normally produced to give the lowest maximum Rockwell hardness for each grade.
1.1.2Soft annealed high-carbon steel is intended for appli-cations requiring moderate cold forming.It is produced to a maximum Rockwell hardness.
1.1.3Intermediate hardness high-carbon steel is intended for applications where cold forming is slight or a stiff,springy product is needed,or both.It is produced to specified Rockwell hardness ranges,the maximum being higher than obtained for the annealed type.
1.1.4Full hard high-carbon steel is intended for flat appli-cations.It is produced to minimum Rockwell hardness require-ments,which vary with grade,microstructure and gage.Full hard can be produced with either a pearlitic or spheroidized microstructure or a mixture of both.The minimum hardness should be established between the consumer and the producer.1.2This specification is applicable for orders in either inch-pound units (as A 684)or SI units (A 684M).
2.Referenced Documents 2.1ASTM Standards:
A 370Test Methods and Definitions for Mechanical Testing of Steel Products 2
A 682Specification for Steel,Strip,High-Carbon,Cold-Rolled,Spring Quality,General Requirements for 2
A 682M Specification for Steel,Strip,High-Carbon,Cold-Rolled,Spring Quality,General Requirements for [Met-ric]2
E 3Methods of Preparation of Metallographic Specimens 33.Terminology
3.1Number 1or matte (dull)finish —finish without luster,
produced by rolling on rolls roughened by mechanical or chemical means.This finish is especially suitable for lacquer or paint adhesion,and is beneficial in aiding drawing operations by reducing the contact friction between the die and the strip.3.2Number 2(regular bright)finish —finish produced by rolling on rolls having a moderately smooth finish.It is less suitable that No.1(matte)finish for cold forming and may be applicable for certain types of plating.
3.3spheroidizing —the heating and cooling of the strip in controlled conditions (annealing)to produce a spheroidal or globular form of carbide microconstituent.
3.4stretcher strains —elongated markings that appear on the surface of the strip when dead soft (fully annealed)material is deformed beyond its yield point (see 5.2).
4.Ordering Information
4.1Orders for material under this specification shall include the following information:
4.1.1ASTM designation and date of issue,4.1.2Name,type,and steel grade number,
4.1.3Hardness (if intermediate or restricted hardness is specified),
4.1.4Decarburization (if required),4.1.5Application,4.1.6Dimensions,
4.1.7Coil size requirements,
4.1.8Edge (indicate No.1round,square,etc.),4.1.9Finish (indicate and specify),
4.1.10Conditions (specify whether material is oiled or dry),4.1.11Package (bare coils,skid,etc.),
4.1.12Cast or heat (formerly ladle)analysis report (if required),and
4.1.13Special requirements (if required).
N OTE 1—A typical ordering description is as follows:ASTM A 684dated ———Cold Rolled,High-Carb
on Soft,Strip,Spheroidized 1064,0.042in.by 6in.by coil (16in.ID by 40in.OD max),No.5Edge,No.2Finish,Oiled,Bare Skid or
“ASTM A 684dated ———Cold Rolled,High-Carbon,Soft,Strip,Spheroidized 1064,0.6mm by 200mm by coil (400mm ID by 7500mm OD max),No.3Edge,No.2Finish,Oiled,Bare Skid.”
5.Manufacture 5.1Condition :
editorialize5.1.1The strip shall be furnished cold rolled spheroidized
1
This specification is under the jurisdiction of ASTM Committee A-1on Steel,Stainless Steel and Related Alloys,and is the direct responsibility of Subcommittee A01.19on Steel Sheet and Strip.
Current edition approved Aug.29,1986.Published October 1986.Originally published as A 684–73.Last previous edition A 684–81e 1.2
Annual Book of ASTM Standards ,V ol 01.03.3
Annual Book of ASTM Standards ,V ol 03.01.
1
AMERICAN SOCIETY FOR TESTING AND MATERIALS 100Barr Harbor Dr.,West Conshohocken,PA 19428
Reprinted from the Annual Book of ASTM Standards.Copyright ASTM
annealed,soft annealed,intermediate hardness,or full hard,as specified.
5.1.2Intermediate hardness may be obtained by either rolling the strip after final annealing or by varying the annealing treatment,or both.
5.2Pinch Pass —Spheroidized annealed and annealed ma-terial may be pinch rolled after the final anneal to improve flatness,uniformly oil,modify surface,and minimize stretcher strains if required by the purchaser.
6.Chemical Requirements
6.1Cast or Heat Analysis —The heat or cast analysis shall conform to that specified in Specification A 682or A 682M for the steel grade ordered;or to such other limits as may be specified using the standard ranges in Specification A 682or A 682M.
7.Metallurgical Structure
7.1Pearlite is the normal structure of cold rolled high-carbon strip unless it has had an intermediate anneal.
7.2Annealed is mostly a spheroidized structure,but may contain some vestiges of pearlite.
7.3Spheroidize annealed is essentially free of pearlite.7.4At least one specimen shall be taken from each lot (see Specification A 682or A 682M)for microexamination.
7.4.1The specimens shall be prepared for microscopical examination in accordance with Methods E 3.8.Mechanical Requirements 8.1Hardness :8.1.1Spheroidized Annealed and Annealed Types —When furnished spheroidized annealed or annealed,the hardness of the strip shall not exceed the maximum values specified in Fig.1and Fig.2for the applicable carbon range and type.
8.1.2Intermediate Hardness Type —When furnished as in-termediate hardness,the hardness of the stri
p shall conform to the range specified on the purchase order.The maximum hardness limit and the corresponding minimum shall be speci-fied by the purchaser.If the maximum temper is under Rockwell B 100(15T93or 30T82),that scale should be used exclusively.If the minimum temper is over Rockwell C 20(15N69.5or 30N41.5),that scale should be used exclusively.For accuracy in testing,the hardness scales should not overlap.On either hardness scale,a range of ten points arithmetic difference is required.Refer to Table 1for appropriate scale testing requirements.
8.1.3Full hard is specified to a minimum hardness value.Refer to Table 1for appropriate scale testing requirements.8.1.4At least one specimen shall be taken from each lot (see Specification A 682or A 682M).
8.1.5The sample shall be tested in accordance with Test Methods and Definitions A 370.8.2Bend Test :
8.2.1The steel strip produced as spheroidized,or the annealed type shall meet the cold bend requirement in Table 2.Any visible cracking on the tension side of the bend portion shall be cause for rejection.
8.2.2At least one specimen shall be taken from each lot (see Specification A 682or A
682M).
FIG.1Approximate Relationship Between Carbon Designations and the Maximum Hardness Limit of Soft Type Annealed Cold Rolled
High Carbon Steel
Strip
8.2.3The specimen shall be the full thickness and shall be taken transverse to the rolling direction as described in Test Methods and Definitions A 370.The edges of the bend test specimens shall be rounded and free of burrs;filing or machining is permissible.9.Finish and Edges
9.1Surface —The strip shall be furnished with a No.2Regular Bright or No.1Matte (Dull)finish,as specified.9.2Oiling —The strip shall be furnished oiled or dry,as specified.
9.3Edges —The strip shall be furnished with a No.1round or Square,No.2Mill,No.3Square Slit,No.4Approximately Round,No.5Approximately Square Burr Free,or No.6Approximately Square Edge,as specified.
10.General Requirements
10.1Material furnished under this specification shall con-form to the applicable requirements for the current edition of either Specification A 682or A
682M.
FIG.2Approximate Relationship Between Carbon Designations and the Maximum Hardness Limit of Spheroidized Annealed Cold
Rolled High Carbon Steel Strip TABLE 1Rockwell Hardness Testing Ranges for Cold-Rolled
High-Carbon Steel Strip
Rockwell “B”and “T”Scales Rockwell “C”and “N”Scales Thickness Scale Thickness Scale Over 0.030in.[over 0.8mm]B Over 0.040in.[over 1.0mm]C 0.020to 0.030in.[0.5to 0.8mm]30T 0.025to 0.040in.[0.6to 1.0mm]30N Under 0.020in.[under 0.5mm]
15T
Under 0.025in.[under 0.6mm]
15N
TABLE 2Cold Bending Requirements A ,B for Spheroidized,Annealed,and Soft-Annealed Cold-Rolled Carbon Steel Strip
Type
Degree of Bend Inside Radius to Thickness
Relation of Bend Test Specimen to Rolling Direction Annealed Spheroidized
180°180°
3t 2t
transverse C transverse C
A
Up to 0.100in.[2.5mm],incl,thickness maximum.When bend radius for thickness is over 0.100in.[2.5mm]the producer should be consulted.These ratios apply to bending performance of the test specimen.B
These bend tests apply to the bending performance of test specimens only.Where material is to be bent in fabricating operations a more liberal bend radius may be required and should be based on prior experience or consultation with the steel producer,or both.C
If finished strip width prohibits taking a transverse bend test specimen,
a longitudinal specimen may be substituted,except the bend radius shall be reduced by 1t .
The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard.Users of this standard are expressly advised that determination of the validity of any such patent rights,and the risk of infringement of such rights,are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed everyfive years and if not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters.Your comments will receive careful consideration at a meeting of the responsible technic
al committee,which you may attend.If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards,100Barr Harbor Drive,West Conshohocken,PA19428.

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