High toughness high hardenability spring steel material

Abstract

A spring steel suitable for plate spring contains C (0.48-0.55 wt.%), Si (0.17-0.37), Mn (0.7-1.0), Cr (0.8-1.1), B (0.001-0.004), Ni (0-0.35), Cu (0-0.25), P (0-0.03), S (0-0.03) and Fe (rest). Its advantages are high strength, high toughness and high hardenability.

Description

technical field [0001] The invention belongs to the field of preparation of spring steel in functional materials, and is suitable for manufacturing steel materials of elastic elements with large cross-section and high strength and toughness, especially suitable for manufacturing steel materials of leaf springs with thickness ≥ 20 mm and ≤ 36 mm. Background technique [0002] At present, the commonly used large-section spring steel materials mainly include 60CrMnBA, 50CrVA, and SUP9 (equivalent to 55CrMnA in GB1222-92), of which 60CrMnBA only has high hardenability and high strength, but does not have high toughness. During the quenching process, due to the large heat treatment stress, the tendency of quenching cracking is large, so that it is basically out of use in the domestic leaf spring industry; 50CrVA has good strength and toughness, high hardenability, but with There is a big gap in the hardenability of 60CrMnBA, and because it contains relatively expensive alloying e...

AI Technical Summary

Problems solved by technology

[0002] At present, the commonly used large-section spring steel materials mainly include 60CrMnBA, 50CrVA, and SUP9 (equivalent to 55CrMnA in GB1222-92), of which 60CrMnBA only has high hardenability and high strength, but does not have high toughness. During the quenching process, due to the large heat treatment stress, the tendency of quenching cracking is large, so that it is basically out of use in the domestic leaf spring industry; 50CrVA has good strength and toughness, high hardenability, but with There is a big gap in the hardenability of 60CrMnBA, and because it contains relatively expensive alloying element vanadium V, the cost is high; while the price of the Japanese brand SUP9 (equivalent to 55CrMnA in GB1222-92) is slightly lower, regardless of hardenability , or the strength and toughness are obviously low, and it is not an ideal large-area spring steel material.

[0003] Due to the above-mentioned several commonly used large-section spring steels, whether it is the material in the national standard GB1222-92 or the Japanese brand SUP9 material that is widely used in China at present, they cannot have the comprehensive properties of high strength, toughness and high hardenability at the same time.