GCr15轴承钢大圆材的球化退火工艺

Spheroidizing annealing process of big size bar of bearing steel GCr15

针对GCr15轴承钢大圆材球化合格率低和沿钢材横截面球化不均等问题,进行了快速和等温球化退火工艺试验。结果表明,采用等温球化退火工艺,并适当减少奥氏体化保温时间至14 h,降低球化珠光体转变温度至680℃、延长保温时间至25 h,能够显著提高轴承钢大圆材球化合格率,同时可以获得从钢材中心到边缘较为均匀细小弥散分布的球化组织。

Different spheroidizing annealing ( fast spheroidizing and isothermal spheroidizing) were tested based on problems such as low pass rate of spheroidized microstructure inspection and inhomogeneous spheroidized structure on cross section of big size bar of bearing steel GCr 15. The results show that taking measures such as adopting isothermal spheroidizing annealing, reducing soaking time at austenitizing temperature to 14 h, lowering pearlite transformation temperature to 680℃and extending the holding time to 25 h can obviously improve the pass rate of spheroidized structure inspection, and at the same time obtain even, fine and disperse distributed spheroidized microstructure from the center to the edge of the steel.