Q355ME耐低温角钢边宽冲击韧性分布和显微组织研究

Study on mircostructure and impact toughness along the edge width of Q355ME low-temperature resistant angle steel

针对Q355ME耐低温角钢整体性能均匀的要求,采用金相显微镜、扫描电子显微镜以及冲击试验研究了Q355ME耐低温角钢沿边宽不同位置的组织和性能。结果表明,从端部到根部,不同位置显微组织均为铁素体+珠光体,但铁素体体积分数和晶粒尺寸大小有明显差别。沿边宽不同位置的冲击试样低温(-40℃)冲击功为148~203J,从端部到根部呈先减小后升高的趋势。角钢端部的冲击功最大,在靠近根部1/3位置的冲击功为最小值,根部冲击功接近标准取样位置的冲击值。Q355ME耐低温角钢沿边宽不同位置冲击性能和显微组织存在差别,但性能均满足标准要求。

Aiming at the requirement of uniform performance of Q355ME low-temperature resistant angle steel,the microstructure and performance of Q355ME low-temperature resistant angle steel at different positions along the edge width were studied using metallographic microscope,scanning electron microscope and impact test.The results show that from the end to the root,the microstructures at different positions are ferrite+pearlite,but the volume fraction of ferrite and grain size are obviously different.The impact energy of samples at different positions along the edge width at low temperature(-40℃)is 148~203J,which firstly decreases and then increases from the end to the root.The impact energy at the end of the angle steel is the largest,the impact energy near the root 1/3is the minimum,and the root impact energy is close to the impact value at the standard sampling position.Q355ME low-temperature resistant angle steel has different impact performance and microstructure at different positions along the edge width,but the performance meets the standard requirements.