对于φ>200mm 的大型零件,如高硬冷轧辊、轧槽块、发电机和汽轮机转子等进行淬火处理,是使距工件表面一定的层深获得马氏体组织,即获得一定的淬硬层,以满足零件的服役要求。但是,由于零件截面大、质量大,相变潜热大,加之受钢的淬透性、散热与淬火介质的限制,往往淬不上火,硬 For φ> 200mm large parts, such as high hardness cold roll, rolling block, generator and steam turbine rotor quenching process is to get a certain depth from the surface of the workpiece to obtain martensite, that is, to obtain a certain hardened layer To meet the service requirements of the parts. However, due to large parts cross-section, mass, large latent heat of phase change, combined with the hardenability of the steel, heat and quenching medium, often quenching does not get angry, hard