强化机制对钢的冷脆特性的影响

Effect of Hardening Mechanism on Cryogenic Brittleness of Steel

本文研究了在沉淀强化和细晶强化两种机制分别作用的处理条件下低碳钢系列温度断裂行为阐明了不同强化机制对钢件塑一脆转变特性的影响。结果表明,沉淀强化不影响材料解理特征应力 S_(c0),钢的冷脆特征温度 T~*_c 增高系由屈服极限σμ的提高引起。而在细晶强化条件下σ_y和 S_(c0)均得到提高且后者提高的幅度大于前者,故使 T~*_c 降低。

The fracture behavior of mild steels was investigated at different temper- atures using specimens heat-treated under conditions of precipitation and grain-refining.The effect of hardening mechanism on ductile-to-brittle transition of steel was studied.The results indicate that.with precipitation hardening,cleavage--characteristic stress of the material,S_(C0),keeps unaffected, and thus,elevation of the cryogenic arittleness-characteristic temperature Tc~* is due to an increase in yield strength σ_y.With grainrefining hardening, both σ_y and S_(C0) are elevated,and the elevation range of the latter is larger than that of the former,as a result,it makes T_c~* descend.