摘要
以NM400耐磨钢为研究对象,应用Gleeble-1500热模拟机分别研究了静态下和动态下冷却速度对NM400耐磨钢组织的影响。结果表明:在静态下冷速为5℃/s时得到的组织为铁素体+贝氏体,随着冷速的增加贝氏体转变范围增加,当冷速为30～50℃/s时得到的组织为贝氏体+马氏体组织;而动态下冷却速度为0.5～1.0℃/s时组织为多边形铁素体+粒状贝氏体;冷速为5～15℃/s时粒状贝氏体组织转变为板条贝氏体组织,冷却速度在20℃/s以上,组织主要是贝氏体+马氏体。通过动态连续冷却组织的分析,建议直接淬火工艺为:冷却速度应该大于15℃/s以便得到贝氏体组织或者贝氏体和马氏体的混合组织,冷却开始温度应该在800～850℃,而冷却结束温度在400～450℃。
The influences of cooling rate on microstructure of NW400 wear-resistant steel at static and dynamic state were studied by Gleeble-1500.The results show that the bainitic-ferrite microstructure can be gotten at 5 ℃/s cooling rate in the static state.The bainictic transformation range increases with the cooling rate increasing.The bainite-martensite can be obtained when the cooling rate is from 30 ℃/s to 50 ℃/s.Whereas,the polygonal ferrite ＋ granular bainite can be gotten when the cooling rate is from 0.5 ～1.0 ℃/s in the dynamic state,when the cooling rate is from 5 ℃/s to 15 ℃/s,the granular bainite transforms into lathe bainite.When the cooling rate is above 20 ℃/s,the microstructure is mainly bainite-martensite.By microstructure analysis of dynamic continuous cooling,the proposed direct quenching process is that the cooling rate should be greater than 15 ℃/s to obtain bainite or banite-martensite,as well the cooling starting temperature should be around 800 ℃～850 ℃,the cooling end temperature should be 400 ℃～450 ℃.
出处
《热加工工艺》
CSCD
北大核心
2012年第10期4-6,共3页
Hot Working Technology
基金
唐山市科学技术及发展计划项目(10110204A)
关键词
耐磨钢
冷却速度
组织
wear-resistant steel
cooling rate
microstructure
