加热工艺对780MPa级双相高强钢奥氏体晶粒和析出相的影响
EFFECT OF HEATING PROCESS ON AUSTENITE GRAIN AND PRECIPITATES IN 780 MPa GRADE DUAL PHASE HIGH STRENGTH STEEL
高江涛 1武冠华 1杜秀珍 1吴云哲 1汪云辉 1蒋昭阳1
作者信息
- 1. 唐山钢铁集团有限责任公司,河北唐山 063016
- 折叠
摘要
双相高强钢成分中含有Nb、V、Ti等多种合金元素,加热温度和加热时长对钢中奥氏体晶粒尺寸、合金元素的溶解和析出及再结晶均有影响,从而对产品的最终组织和性能也产生较大影响.本文通过金属材料模拟软件Jmatpro对780 MPa级双相高强钢中的析出相进行了计算.由计算结果可知,在950～1 600 ℃范围内,试验钢中主要存在MN、M(C,N)和MB2三种平衡析出相,MN的析出温度为1 460 ℃,M(C,N)的析出温度为1 108 ℃,MB2的析出温度为1 147 ℃.退火试验表明:加热温度对780 MPa级双相高强钢奥氏体晶粒尺寸影响较为显著.当加热时长为30 min时,1 200～1 300 ℃为加热温度安全区间,在该温度范围内晶粒尺寸适宜且均匀,低于该范围混晶现象较重,高于该范围则晶粒粗化;加热温度为1 250 ℃时,780 MPa级双相高强钢奥氏体晶粒尺寸随加热时长增加而增加,但加热时长对奥氏体晶粒尺寸的影响效果较弱.
Abstract
The composition of dual-phase high-strength steel contains many alloying elements such as Nb,V and Ti.The heating temperature and heating time have an effect on the austenite grain size,the dissolution,precipitation and recrystallization of alloying elements in the steel,which also have a great impact on the final structure and properties of the product.In this paper,metal material simulation software Jmatpro was used to calculate the precipitated phase in 780 MPa grade dual-phase high-strength steel.According to the calculation results,there are mainly three equilibrium precipitated phases of MN,M(C,N)and MB2 in the test steel in the range of 950～1 600 ℃,and MN begins to precipitate at 1 460 ℃.M(C,N)begins to precipitate at 1 108 ℃.MB2 begins to precipitate at 1 147℃.The annealing test shows that the heating temperature has a significant effect on the austenite grain size of 780 MPa dual-phase high-strength steel.When the heating time is 30 min,1 200～1 300 ℃ is the safe temperature range,the grain size is appropriate and uniform within the temperature range,below the range of mixed crystal phenomenon is serious,above the range of grain coarsening;When the heating temperature is 1 250 ℃,the austenite grain size of 780 MPa dual-phase high-strength steel increases with the increase of heating time,but the effect of heating time on the austenite grain size is weak.
关键词
双相高强钢/加热温度/加热时间/奥氏体/晶粒尺寸/析出相Key words
dual phase high-strength steel/heating temperature/heating duration/austenite/grain size/precipitates引用本文复制引用
出版年
2024
NETL
NSTL
万方数据