【摘要】 设计了一类 (0 38～ 0 4 4) %C Mn Si Cr成分的贝氏体钢汽车板簧材料 ,测定了常规力学性能 ,分析了组织特征。结果表明 ,该钢奥氏体化后空冷具有贝氏体 /马氏体复相组织 ;奥氏体化后空冷 ,经中低温回火后 ,其力学性能σb≥ 180 0MPa ,σ0 2 ≥ 16 0 0MPa ,δ5≥ 7%,ψ≥ 35 %,均显著超过 6 0Si2Mn钢的性能 ,屈强比 >0 8。钢中较高的Si含量使钢的第一类回火脆性温度升高 ,但随含碳量的增加 ,出现低温回火脆性的初始温度相应降低更多还原

【Abstract】 A type of bainitic steel for automobile leaf spring with the composition of （0.38～0.44）%C-Mn-Si-Cr was designed,and their conventional mechanical properties were measured and the microstructures were observed and analyzed.The results show that bainite/martensite mixed microstructure can be obtained by air cooling after austenization of this type bainitic steel.After being austenitized,then air-cooled and tempered at low temperature,their mechanical properties σ_b,σ_0.2,δ₅ and ψ are more than 1800MPa,1600MPa,7% and 35% respectively.All properties of the designed steel are obviously more than these of 60Si2Mn steel,and the yield ratio of the designed steels is more than 0.8.The starting temperature appearing the one-step temper brittleness rises owing to the higher content of silicon in the steel,however,it will reduce with the increase of the carbon content.更多还原