Active Standard ASTM A304 | Developed by Subcommittee: A01.15
Book of Standards Volume: 01.05
Historical (view previous versions of standard)
This specification covers carbon and alloy steel bars subject to end-quench hardenability requirements. The methods for estimating the hardness value of the material are presented. Method A is the minimum and maximum hardness values at any desired distance, Method B is the minimum and maximum distances at which any desired hardness value occurs, Method C is the two maximum hardness values at two desired distances, Method D is the two minimum hardness values at two desired distances, and Method E is any minimum hardness plus any maximum hardness. The heat analysis shall conform to the requirements as to chemical composition. The fine austenitic grain size requirements of the steel material are presented in details. The end-quench hardenability shall conform to the requirements specified on the purchase order. The test specimen requirements indicates that, the number and location of test specimens shall be in accordance with the manufacturers standard practice and shall adequately represent the hardenability of each heat, also, all forged or rolled hardenability test specimens must be normalized prior to testing. The grain size and end-quench hardenability test methods are presented in details.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
1.1 This specification covers hot-worked alloy, carbon, and carbon-boron steels in a variety of compositions and sizes, which may attain specified depth of hardening in the end quench test. These steel compositions are identified by the suffix letter “H” added to the conventional grade number.
1.2 This specification provides for analyses other than those listed under Tables 1 and 2. Special hardenability limits are also permissible when approved by the purchaser and manufacturer.
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.
TABLE 2 Chemical Requirements of Carbon H-SteelsA
|UNS DesignationB||Grade Designation||Chemical Composition, %|
|H 10380||1038 H||0.34–0.43||0.50–1.00||0.040||0.050||0.15–0.35|
|H 10450||1045 H||0.42–0.51||0.50–1.00||0.040||0.050||0.15–0.35|
|H 15220||1522 H||0.17–0.25||1.00–1.50||0.040||0.050||0.15–0.35|
|H 15240||1524 H||0.18–0.26||1.25–1.75||0.040||0.050||0.15–0.35|
|H 15260||1526 H†||0.21–0.30||1.00–1.50||0.040||0.050||0.15–0.35|
|H 15410||1541 H||0.35–0.45||1.25–1.75||0.040||0.050||0.15–0.35|
|H 15211C||15B21 HC||0.17–0.24||0.70–1.20||0.040||0.050||0.15–0.35|
|H 15351C||15B35 HC||0.31–0.39||0.70–1.20||0.040||0.050||0.15–0.35|
|H 15371C||15B37 HC||0.30–0.39||1.00–1.50||0.040||0.050||0.15–0.35|
|H 15411C||15B41 HC||0.35–0.45||1.25–1.75||0.040||0.050||0.15–0.35|
|H 15481C||15B48 HC||0.43–0.53||1.00–1.50||0.040||0.050||0.15–0.35|
|H 15621C||15B62 HC||0.54–0.67||1.00–1.50||0.040||0.050||0.40–0.60|
|†Correction made editorially|
A Standard H Steels can be produced with a lead range of 0.15–0.35 %. Such steels are identified by inserting the letter “L” between the second and third numerals of the grade designation, for example, 15L22 H. Lead is generally reported as a range of 0.15–0.35 %.
B New designations established in accordance with Practice E527 and SAE J 1086, Recommended Practice for Numbering Metals and Alloys (UNS).
C These steels can be expected to have 0.0005 % min boron content.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
A29/A29M Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements for
A108 Specification for Steel Bar, Carbon and Alloy, Cold-Finished
A255 Test Methods for Determining Hardenability of Steel
E112 Test Methods for Determining Average Grain Size
E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)
ICS Number Code 77.140.60 (Steel bars and rods)