摘要
通过对20CrMaTi 钢不同温度的预固溶热处理、析出处理和 TEM 分析,研究了沉淀相 TiC的析出行为。发现经1200℃高温固溶热处理后,TiC 在预析出温度分别为810℃和930℃时析出量多而且细小;同时钢的奥氏体晶粒度级别增大,淬透性随预析出温度的提高,呈下降趋势,1000 ℃左右达到最低点,而后又有所提高。这一结果表明,可以通过预先热处理工艺措施,改变 TiC 的析出行为,以达到控制钢的奥氏体晶粒度和淬透性的目的。
The precipitation behaviour of TiC in 20CrMnTi steel after presoluted and precipitated treatment at various temperatures,has been investigated with TEM.The results are discovered:TiC phase is precipitated in large amount and thin in size at 810℃ or 930℃ after solution heat treatment at 1200 ℃.In the meantime,the grain size of austenite is increased,and the harden- ability is decreased with the increasing of precipitated temperature,and there is a minimum value at 1000℃,there after increased slightly.These above results indicate that changing precipitation behaviour of TiC can control auste- nite grain size and hardenability of the steel by appropriate preheat treatment technology.
关键词
TiC相
奥氏体
淬透性
渗碳钢
20CrMnTi
TiC
austenite grain size
hardenability
