Q690D-QT高强钢材的高温动态拉伸力学性能
Tensile mechanical properties of Q690D-QT at high temperatures and high strain rate
陈素文 1魏鑫纳 2李国强1
作者信息
- 1. 同济大学土木工程防灾减灾全国重点实验室,上海 200092;同济大学土木工程学院,上海 200092
- 2. 同济大学土木工程学院,上海 200092
- 折叠
摘要
为了研究温度20～700 ℃下国产Q690D-QT高强钢的拉伸力学性能,开展了系列高温准静态和动态拉伸力学性能试验.试验结果表明:准静态拉伸下随温度上升,弹性模量和名义屈服强度f0.2、f0.5(其中f0.2取为应力-应变曲线和应变0.2％比例偏移线交点的应力,f0.5取应变为0.5％时对应的应力)不断下降,而名义屈服强度f1.0、f1.5、f2.0(其中f1.0、f1.5、f2.0分别取应变为1.0％、1.5％和2.0％时对应的应力)和抗拉强度在200～300 ℃间先略有上升,后不断下降;动态拉伸下屈服强度在室温下应变率效应不明显,在700℃时应变率效应明显.进一步地,采用多项式拟合给出了准静态弹性模量、屈服强度和抗拉强度的高温折减系数预测公式;并标定了可有效描述温度20～700 ℃、应变率1 000 s-1下Q690D-QT高强钢拉伸力学性能的 Johnson-Cook 模型参数(A=760 MPa,B=402 MPa,n=0.534,C=0.004,m=0.966).
Abstract
Through the steady-state test and high-temperature SHTB test of domestic high-strength steel Q690D-QT,the quasi-static and dynamic tensile mechanical properties of the steel at 20-700 ℃ were investigated.The steady-state test results show that the elastic modulus and the nominal yield strength f0.2 and f0.5(f0.2 is the intersection point of the stress-strain curve and the proportional line offset by 0.2％strain,f0.5 is determined from the intersection of the stress-strain curve and vertical line at 0.5％strain)decrease continuously with the increase of temperature,while the nominal yield strength f1.0,f1.5,f2.0(f1.0,f1.5 and f2.0aredetermined from the intersection of the stress-strain curve and vertical line at 1.0％,1.5％,and 2.0％strain)and ultimate strength first increased slightly between 200-300 ℃ and then decreased continuously.The dynamic test results show that the strain rate effect of tensile yield strength at 700 ℃is more significant than that at room temperature.With polynomial fitting,prediction formulae were obtained for the elastic modulus,yield strength,and ultimate strength reduction coefficient.The Johnson-Cook model parameters(A=760 MPa,B=402 MPa,n=0.534,C=0.004,m=0.966)were determined to describe the high-temperature dynamic tensile mechanical properties of Q690D-QT high-strength steel at temperature ranging from 20 ℃ to 700 ℃and at a strain rate of 1 000 s-1.
关键词
高强钢/高温/准静态试验/动态试验/拉伸力学性能Key words
high-strength steel/elevated temperature/quasi-static test/dynamic test/tensile mechanical property引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
维普
万方数据