Реферат

This specification covers the chemical, mechanical, and metallurgical requirements for two types of heavy hex structural bolts made of quenched and tempered alloy steel and having specified tensile strengths and sizes. These bolts are intended for use in structural connections, and are furnished in nominal bolt diameters M12 through M36. They are designated by type denoting chemical composition as follows: Type 1—medium carbon alloy steel; and Type 3—weathering steel. The bolts shall conform to chemical requirements as examined by heat and product analysis. The bolts shall also be tested, and shall conform accordingly to specified requirements for mechanical properties such as Brinell hardness, Rockwell hardness, microhardness, tensile strength, yield strength, elongation, reduction of area, stress area, tensile load, and proof load; metallurgical properties such as carburization and decarburization; and dimensional properties such that for the head and body, and threads. The bolts shall undergo magnetic particle inspection as well for longitudinal discontinuities and transverse cracks.

Область применения

1.1 This specification covers two types of quenched and tempered alloy steel, metric heavy hex structural bolts having a tensile strength of 1040 to 1210 MPa.

1.2 These bolts are intended for use in structural connections comparable to those covered under the requirements of the Specification for Structural Joints Using ASTM and bolts, approved by the Research Council on Structural Connections; endorsed by the American Institute of Steel Construction and by the Industrial Fastener Institute.

1.3 The bolts are furnished in nominal bolt diameters M12 to M36, inclusive. They are designated by type denoting chemical composition as follows:

TypeDescription Type 1Medium carbon alloy steel Type 2Withdrawn in 2002 Type 3Weathering steel

1.4 This specification is applicable to metric heavy hex structural bolts and alternate designs as established by the Research Council in its publication, Specification for Structural Joints Using ASTM and bolts.

1.5 For inch-pound bolts, see Specification A490.

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 The following safety hazards caveat pertains only to the Test Methods portion, Section 13, of this specification: 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.

TABLE 1 Chemical Requirements for Type 1 Bolts

Element
Heat Analysis, %
Product Analysis, %
Carbon
For sizes through M30
0.30–0.48
0.28–0.50
For size M36
0.35–0.53
0.33–0.55
Phosphorus, max
0.040
0.045
Sulfur, max
0.040
0.045 Alloying Elements → See 6.1 ←

TABLE 2 Chemical Requirements for Type 3 Bolts

Element
Heat Analysis, %
Product Analysis, %
Carbon Sizes M20 and smaller0.20–0.530.19–0.55 Sizes larger than M20.0.30–0.530.28–0.55 Manganese, min0.40 0.37 Phosphorus, max0.0350.040 Sulfur, max0.0400.045 Copper0.20–0.600.17–0.63 Chromium, min0.45 0.42 Nickel, min
or0.20 0.17 Molybdenum, min0.15 0.14