铝氮比对轿车用渗碳钢晶粒混晶的影响

摘要

在转炉长流程生产工艺条件下，研究了铝含量、氮含量和铝氮比对轿车用20MnCr5渗碳钢晶粒度混晶的影响。结果表明，在规定的热处理工艺条件下，20MnCr5渗碳齿轮钢产生混晶的主要原因是钢中氮含量偏低。当20MnCr5钢中铝含量≥00．25％且铝氮比≥3时，可以达到轿车渗碳钢对奥氏体晶粒度的要求。%It is researched the influence of contents of aluminum and nitrogen and their proportion on mixed grain size of 20MnCr5 carburizing steel for cars in long process of converter.The result shows that under the specified heat treatment process, the main reason for mixed grain in 20MnCr5 carburizing gear steel is too low nitrogen content in steel.The demand of car carburizing steel for austenite brain size can be met if the a-luminum content not being lower than 0.025%and aluminum-nitrogen proportoi n notb eing smallert han 3.