Реферат

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.

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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-Steels^A

UNS Designation^B
Grade Designation
Chemical Composition, %
Carbon
Manganese
Phosphorus,
max
Sulfur,
max
Silicon
H 10380 1038 H0.34–0.430.50–1.00 0.0400.0500.15–0.35 H 10450 1045 H0.42–0.510.50–1.00 0.0400.0500.15–0.35 H 15220 1522 H0.17–0.251.00–1.50 0.0400.0500.15–0.35 H 15240 1524 H0.18–0.261.25–1.75 0.0400.0500.15–0.35 H 15260 1526 H†0.21–0.301.00–1.50 0.0400.0500.15–0.35 H 15410 1541 H0.35–0.451.25–1.75 0.0400.0500.15–0.35 H 15211^C15B21 H^C0.17–0.24 0.70–1.200.0400.050 0.15–0.35 H 15351^C15B35 H^C0.31–0.39 0.70–1.200.0400.050 0.15–0.35 H 15371^C15B37 H^C0.30–0.39 1.00–1.500.0400.050 0.15–0.35 H 15411^C15B41 H^C0.35–0.45 1.25–1.750.0400.050 0.15–0.35 H 15481^C15B48 H^C0.43–0.53 1.00–1.500.0400.050 0.15–0.35 H 15621^C15B62 H^C0.54–0.67 1.00–1.500.0400.050 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.