回火温度对5.5Ni低温钢组织和力学性能的影响

发布时间：2018-09-12 13:55

【摘要】：用XRD,SEM及TEM等手段表征5.5Ni钢在不同回火温度下逆转变奥氏体的含量、形貌和尺寸等的变化,研究了回火温度对5.5Ni钢力学性能的影响规律。结果表明:在580-600℃回火后5.5Ni钢的抗拉强度和屈服强度变化不明显;在620℃回火后抗拉强度小幅度提高,屈服强度却大幅度降低,延伸率持续升高;在580-620℃回火,随着回火温度的提高5.5Ni钢中的逆转变奥氏体体积分数虽逐渐增加,冲击功却不断降低。稳定程度高且细小均匀弥散分布的片层状逆转变奥氏体,是在580℃回火后冲击功高达148 J的主要原因。钢中有两类逆转变奥氏体,一类是片层状的,宽度为20 nm,长度不一,有利于提高钢的低温韧性;另一类是块状的,呈团簇状分布,尺寸约为200 nm,对钢的低温韧性有害。
[Abstract]:The changes of austenite content, morphology and size of 5.5Ni steel at different tempering temperatures were characterized by means of XRD,SEM and TEM. The effect of tempering temperature on the mechanical properties of 5.5Ni steel was studied. The results show that the tensile strength and yield strength of 5.5Ni steel do not change obviously after tempering at 580-600 鈩，

本文编号：2239210