大热输入焊接Q460D结构钢的研制及焊接热模拟试验

Development and Welding Thermal Simulation Test of theStructural Steel Q460D for High Heat Input Welding

利用50 kg真空电炉、小型试验轧机等设备进行了大热输入焊接Q460D结构钢板的试制。试制钢板以Cu作为主要强化元素,未添加Mo、Cr元素,有效控制了钢板成本。钢板采用全Ti脱氧工艺冶炼,然后经过控轧控冷及回火热处理获得最终成品。对钢板进行了不同回火温度后的力学性能检验和焊接热模拟试验。结果表明,610℃回火热处理时,钢板本身的强韧性匹配最佳。该回火工艺处理的钢板在100～120 kJ/cm大热输入焊接条件下,焊接热影响区粗晶区(CGHAZ)-20℃低温冲击功大于100 J,CGHAZ强度不低于基材。

The structural steel Q460D for high heat input welding was trial-manufactured by using a 50 kg vacuum electrical furnace,a small-sized experimental rolling mill and other equipments.Cu,instead of Mo and Cr,was the main strengthening element of the steel plates,so the cost of plates was effectively controlled.The steel plate was smelted by using Ti deoxidation process,and then after controlled rolling,controlled cooling and tempering treatment,final products were obtained.The steel plates under different tempering temperature were studied by mechanical property tests and welding thermal simulation test.The results show that when the temperature of tempering treatment was 610 ℃,the strength and toughness of the plates match best.Under 100～120 kJ/cm high heat input welding conditions,the-20 ℃ low temperature impact energy of the welding coarse-grained heat-affected zone（CGHAZ） of the plates so produced is greater than 100 J,and the CGHAZ strength is not less than the substrate.