摘要
对于航天用超高强高韧C300马氏体时效钢来说,热加工过程中获得等轴细小的再结晶晶粒是实现该钢强韧性最佳匹配的关键环节。采用Gleeble-3800热模拟试验机在温度为850～1 150℃、应变速率为0.01～10 s^(-1)的条件下,对超高强高韧C300马氏体时效钢进行高温轴向压缩变形试验,获得了高温流变曲线,并观察变形后的金相组织。结果表明:C300马氏体时效钢的流变应力和峰值应变随着变形温度的升高和应变速率的降低而减小;试验钢在真应变为0.92、应变速率为0.01～10 s^(-1)的条件下,随着变形速率的提高,其发生完全动态再结晶的温度也逐渐升高,最佳热变形温度区间为1 050～1 150℃;测得试验钢的热变形激活能Q值为391.2 kJ/mol,建立了其热变形本构方程。结果能为C300马氏体钢的数值模拟和热加工工艺的制定提供理论基础。
For C300 maraging steel with super high strength and toughness used for aerospace,the key to achieve the best matching of strength and toughness is to obtain equiaxed fine recrystallized grains during hot working.With the temperature of 850-1 150 ℃ and the strain rate of 0.01-10 s^-1,the Gleeble-3800 thermal simulator is used to test C300 with super high strength and toughness.The high temperature axial compression deformation test of C300 maraging steel is carried out,the high temperature rheological curve is obtained,and the metallographic structure after deformation is observed.The results show that flow stress and peak strain of C300 maraging steel decrease with the increase of the deformation temperature and the decrease of the strain rate.With true strain of 0.92 and the strain rate of 0.01-10 s^-1,as the deformation rate increases,the temperature at which complete dynamic recrystallization occurs gradually increases.The optimum hot deformation temperature range is 1 050 -1 150 ℃ and the thermal deformation activation energy Q of the tested steel is 391.2 kJ/mol.The constitutive equation of the hot deformation is established.The results can provide theoretical basis for the numerical simulation of C300 martensitic steel and the formulation of the hot working process.
作者
李辉
鹿启栋
张大伟
黄顺喆
LI Hui;LU Qidong;ZHANG Dawei;HUANG Shunzhe(Shanghai Spaceflight Precision Machinery Institute,Shanghai 201600,China;General Institute of Iron and Steel Research,Beijing 100044,China)
出处
《上海航天》
CSCD
2019年第2期111-117,共7页
Aerospace Shanghai
关键词
马氏体时效钢
金相组织
流变应力
热变形激活能
maraging steel
metallographic structure
flow stress
thermal deformation activation energy
