氮对冷轧辊材料组织与热处理的影响

 研究了四种冷轧辊材料的热处理特性，采用TEM、XRD以及氧氮分析仪分析氮对冷轧辊材料组织的影响。结果表明，氮的加入形成热力学性质非常稳定的细小弥散的M(C、N)型碳、氮化物，奥氏体化时能够钉扎晶界，阻滞了晶粒的长大。冷轧辊材料引入适量氮后，淬火温度能提高20-30℃而不会使晶粒显著粗大。同时，固溶在基体中的氮能够增加冷轧辊材料的淬透性，降低临界冷却速度，但是也会略微降低Ms点。

Effect of Nitrogen on Microstructure and Heat Treatment of Cold Forged Roll Materials

Heat treatment characteristics and microstructure of four cold forged roll materials were studied using TEM, XRD and oxygen-nitrogen analyzer. The results showed that, the introduction of nitrogen formed thermal-stable and fine M(C、N) carbonnitrides, which pinning in the grain boundary during austenitizing and blocking the growth of austenitic grains. Comparing with common materials, the cold forged roll material with nitrogen can increase the quenching temperature for 20-30℃ without obvious grain coarsening. Meanwhile, nitrogen which dissolved in matrix can improve the hardenability and reduce the critical cooling speed of cold forged roll. Ms point is decreased either due to the solid solution of nitrogen.