时效温度对超高锰钢组织及性能的影响

Effect of Aging Temperature on Microstructure and Properties of Ultra-high Manganese Steel

超高锰钢作为替代传统的高锰钢的耐磨材料,在高应力、高冲击工况条件下具备优异的抗磨性能,具有比传统高锰钢更高的奥氏体稳定性和水韧处理固溶能力,更快的加工硬化速率,较好的耐磨性。制定了5种不同时效温度的热处理工艺,研究时效温度对合金化超高锰钢的组织和性能的变化规律。实验结果表明:在时效温度为400〜600℃,随着时效温度的升高,碳化物数量增多,奥氏体晶粒逐渐增大。在400〜450℃,随着时效温度的升高,碳化物逐渐增多,大部分处于晶粒内部,少量位于奥氏体晶界处,在500〜600℃,500℃时碳化物逐渐析出于晶界处,到600℃时碳化物大量存在于晶界处,少量存在于晶粒内。因此硬度逐渐增加,冲击韧度先增大后减小,屈服强度、抗拉强度、断后伸长率均呈先增加后减小的趋势,时效温度为450℃时力学性能最好。

Five kinds of heat treatment processes with different aging temperatures were developed to study the effect of aging termperature on the microstructure and properties of aloyed ultra-high manganese steel.The results show that with the increasing of aging temperature at 400~600℃,the amount of carbide increases and the austenite grain gradually increases.At 400-450℃,with the increasing of aging temperature,the carbides gradually increase,most of which are located in the grain interior and a small amount at the austenite grain boundary.When aging at 500-600 ℃,carbides gradually precipitate at grain boundaries at 500℃,and a large amount of carbides exist at grain boundaries and a small amount in grains at 600 ℃.Therefore,the hardness increases gradually,the impact toughness increases first and then decreases,the yield strength,tensile strength and elongation after fracture all increase first and then decrease,and the mechanical properties are the best when the aging temperature is 450℃.