耐候钢JNS高温力学性能研究

Research on High Temperature Mechanical Property of Weathering Steel JNS

采用Gleeble热／力模拟试验机，对耐候钢JNS连铸坯进行了高温力学性能测试，得到了在600～1300℃范围内的应力应变曲线，塑性、强度和硬化系数。测试结果表明，JNS钢断面收缩率均在60％以上，塑性比较好。在塑性曲线上存在两个低塑性区，一个在700℃以下，另一个在二次脆性区800～950℃内。抗拉强度和屈服强度随着温度升高是降低的，在1200℃以上强度很低，受力易产生裂纹。高温段的平均硬化系数较低，变形能力较差，出现裂纹的倾向较高。为避开二次脆性区，矫直点前铸坯的温度应控制在1000℃以上，以防止裂纹的出现。

The cure of Strain-Stress, and hot ductility, the strength, and hardening coefficient of weathering steel JNS slab with temperature were measured in the temperature rang of 600℃-1300℃ by the hot tensile test technique with Gleeble-1500D system. The results showed that its reduction of area is over 60% in the temperature rang, and the ductility of steel JNS is well. There are two areas of low ductility, one is below 700℃, and another is in the brittleness temperature II 800℃-950℃. Tensile strength and yield strength in the temperature range decreased with increasing test temperature, and the slab is easy to produce crack with the little strength over 1200℃. The hardening coefficient is low over 1150℃, the slab is bad on distortion, and its easy to produce crack. In order to keep away from brittleness temperature II, the temperature is over 1000℃ before the point of strengthening, it avoid to produce crack.