2507双相不锈钢高温物理性能研究

Physical properties of 2507 duplex stainless steel at high temperature

采用综合热分析仪、热膨胀分析仪、激光导热仪和热/力模拟试验机分别对2507双相不锈钢进行了综合热分析试验、热膨胀试验、激光导热试验和高温力学试验,以控制连铸坯表面凹陷、裂纹等缺陷。结果表明:2507双相不锈钢的固相线温度为1469.5℃,液相线温度为1446.2℃;温度在100~750℃时,2507不锈钢平均线膨胀系数为16.6061×10^(-6)K^(-1),温度在750~1020℃之间的平均线膨胀系数为14.9162×10^(-6)K^(-1),温度在1020~1400℃时平均线膨胀系数为20.4751×10^(-6)K^(-1);在降温过程中,平均线膨胀系数为-22.6903×10^(-6)K^(-1);2507不锈钢的密度随温度升高而降低;温度从650℃升至1150℃,2507不锈钢的热扩散系数增大了25%;导热系数随温度升高而增大,在1000℃时导热系数达到最大值34 W/(m·K);温度超过1200℃之后,抗拉强度均小于20 MPa。温度在1000~1200℃时,试样的断面收缩率均大于60%,塑性较好,属于高温塑性区。

In this paper,to control the defects such as surface depression and crack of continuous casting billet of 2507 duplex stainless steel,through comprehensive thermal analyzer,thermal expansion analyzer,laser thermal conductivity tester and thermal/mechanical simulation testing machine respectively,2507 duplex stainless steel were have done the comprehensive thermal analysis test,thermal expansion test,laser thermal conductivity test and high-temperature mechanical test were done.The results show that the solidus temperature of 2507 duplex stainless steel is 1469.5℃,and the liquidus temperature is 1446.2℃.When the temperature is between 100℃and 750℃,the average linear expansion coefficient of 2507 stainless steel is 16.6061×10^(-6)K^(-1),between 750℃and 1020℃is 14.9162×10^(-6)K^(-1),and between 1020℃and 1400℃is 20.4751×10^(-6)K^(-1).During the cooling process,the average linear expansion coefficient is-22.6903×10^(-6)K^(-1),the density of 2507 stainless steel decreases with the increase of temperature.The thermal diffusivity of 2507 stainless steel increases by 25%when the temperature increases from 650℃to 1150℃.The thermal conductivity increases with the increase of temperature,and it reaches the maximum value of 34 W/(m·K)at 1000℃.When the temperature exceeds 1200℃,the tensile strength is less than 20 MPa.When the temperature is 1000~1200℃,the reduction of area of the samples is more than 60%,and the plasticity is good,which belongs to the high-temperature plastic zone.