热处理温度和冷速对DP980钢烘烤硬化性能的影响  

Effects of Heat Treatment Temperature and Cooling Rate on Bake-Hardening Properties of DP980 Steel

作　　者：刘香茹[1] 周旭东[2] 李俊[3] 王健[3] 

机构地区：[1]河南科技大学物理工程学院,洛阳471023 [2]河南科技大学材料科学与工程学院,洛阳471023 [3]宝山钢铁股份有限公司研究院,上海201900

出　　处：《机械工程材料》2017年第3期54-57,共4页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(51575162)

摘　　要：采用Gleeble-1500D型热力模拟试验机对DP980钢在不同温度(750,850,950℃)下保温2min,然后以不同的冷速(10,20,50℃·s^(-1))进行冷却,之后进行变形量为0.2%和2%的预应变,再进行170℃×20min的烘烤硬化处理,研究了热处理温度和冷速对DP980钢烘烤硬化性能的影响。结果表明:DP980钢具有较高的烘烤硬化性能,烘烤硬化处理后,铁素体中析出很多尺寸为10～20nm的析出相;当热处理温度为750℃和850℃时,烘烤硬化值随冷速的增加先减小后增大;当热处理温度为950℃时,烘烤硬化值随冷速增加而先增大后减小;在相同的冷速下,烘烤硬化值受热处理温度的影响很大,且冷速越大,影响也越大;当热处理温度为850℃、冷速为50℃·s^(-1)时,烘烤硬化值最高,此时的组织为细小的马氏体板条和铁素体。With the help of Gleeble-1500D thermomechanical simulator, the effects of heat treatment temperature and cooling rate on bake-hardening properties of DP980 steel were studied. The steel was treated at different temperature （750 ℃, 850 ℃and 950 ℃） for 2 rain, and followed by cooling with cooling rates of 10, 20, 50℃.s -1 after that, pre-strains were carried out at deformation amounts of 0.2% and 2%, at last the bake- hardening aging process was completed at 170℃ for 20 min. The results show that, DP980 steel has higher bakehardening property because there are a lot of precipitates with size of 10-20 nm in ferrite after bake-hardening treatment; when heat treatment temperature was 750%（2 and 850 ℃, the bake-hardening value firstly decreased and then increased as the cooling rate increased. But When the heat treatment temperature was 950 ℃, the hake- hardening value exhibited the comrary trend. At the same cooling rate, the bake-hardening value is greatly affected hy the heat treatment temperature, and the influence on the bake-hardening value would be greater when the cooling rate more faster. When the heat treatment temperature was 850℃ and the cooling rate was 50 ℃ · s -1 , the highest bake-hardening could be obtained, and the microstructure of the steel was fine martensite laths and ferrite.

关 键 词：DP980钢 烘烤硬化 热处理 

分 类 号：TG161[金属学及工艺—热处理]