1 500 MPa级铝硅镀层热成形钢的试制及质量评价

为开发1 500 MPa级铝硅镀层热成形钢,采用连退模拟器模拟了 5种退火涂镀工艺,采用拉伸试验机、金相显微镜检测样板力学性能、金相组织及镀层组织,以确定最优退火、涂镀工艺;针对试验中的漏镀缺陷,分析了其产生原因.结果表明,在带钢运行速度为80 m/min,加热温度为770℃,快冷温度为650℃的工艺下,铝硅镀层CR1...

Trial production and quality evaluation of 1 500 MPa grade Al-Si coating hot stamping steel

To develop 1 500 MPa grade Al-Si coating hot stamping steel,five kinds of annealing and coating processes were simulated by using continuous annealing simulator,and the tensile testing machine and metallographic microscope were used to detect the mechanical properties,microstructure and coating structure of the sample sheet,so as to determine the optimal annealing and coating process.Meanwhile,the causes of the plating leakage defects in the test were analyzed.The results show that the mechanical properties of CR1000/1500HS+AS steel strip with Al-Si coating are the best when the strip running speed is 80 m/min,the heating temperature is 770 ℃ and the rapid cooling temperature is 650 ℃.The low dew point temperature in the heating section of annealing furnace is the fundamental cause of plating leakage.Therefore,the problem of plating leakage was solved by adjusting the dew point of heating section to -10--20 ℃.The finished sample was taken for simulated hot stamping test,and the properties were qualified after hot stamping.The microstructure was martensite without decarburization layer,and the coating cracks did not extend to the substrate.It can meet the requirements of customers for coating quality.