Abstract: The curves of hardenability of 07MnCrMoR hydropower steel plate are tested, and the 100 mm thick tested steel plate is quenched and tempered by heat treatment furnace and quenching equipment, and the structure of and mechanical properties of test steel are observed and measured. The results show that with increasing the distance from cooling end the microstructure of tested steel transforms from martensite to granular bainite, and transforms to ferrite and granular bainite microstructure at 50 mm from the water-cooled end. The lath bainite + granular bainite + pre-eutectoid ferrite are obtained in test steel plate after quenching by queching equipment, then transforming into ferrite + granular bainite after tempered ,and a large number of carbides precipitating at ferrite matrix and grain boundary. The most reasonable heat treatment process of the test steel is water-cooled quenching at 930 ℃ for 30 min and air-cooled at 660℃ for 60 min.

Key words: Ultea-thick, 07MnCrMoR, Hydropower Steel, Quenched and Tempered, End Quenching Test

摘要： 对07MnCrMoR水电钢板的淬透性曲线进行了测定,利用淬火机和热处理炉对100 mm厚试验钢板进行了淬火和回火试验,并对试验钢进行了组织观察和力学性能测定。结果表明,随着试验钢距水冷端的距离增大,淬火组织由马氏体转变为粒状贝氏体,距离端部50 mm处转变为铁素体和粒状贝氏体的混合组织。试验钢板利用淬火机淬火后得到板条贝氏体+粒状贝氏体+先共析铁素体,回火后转变为铁素体+粒状贝氏体,同时大量的碳化物在铁素体基体和晶界处析出。试验钢最合理的热处理工艺为930℃ 30min水冷淬火,660℃ 60min空冷回火。