超大型液化气船用国产碳锰低温钢焊接性能研究

Study on the Welding Property of Domestic Carbon Manganese Low Temperature Steel on Supersized Liquefied Gas Carrier

以实现超大型液化气船用国产低温钢应用为目的,对华菱湘钢研制的LR LTFH36(VL4-4L M36)碳锰低温钢进行了以下试验研究:(1)利用MMS-200热力模拟试验机采用膨胀法测得该试验钢的临界点温度为Ac1=747℃、Ac3=855℃并获得模拟焊接热影响区连续冷却转变曲线。(2)按劳氏船级社标准进行了平位置埋弧焊和平位置、横位置和立位置的药芯焊丝CO_(2)焊的焊接工艺评定。(3)进行了火工加热至900℃空冷、550℃以下水冷的多次火工工艺,掌握了国产低温钢的焊接加工工艺及火工加工工艺性能,可用于指导国产低温钢在超大型液化气船上的工程化应用。

To achieve domestic carbon manganese low temperature steel on supersized liquefied gas carrier is very significant.Experimental studies on carbon manganese low temperature steel LR LTFH36(VL4-4L M36)developed by Xiangtan Iron and Steel Group Co.,Ltd.were conducted as follows:(1)The thermomechanical simulator MMS-200 was employed to simulate the welding thermal cycle processes of LR LTFH36.The results show that the critical point temperature was Ac1=747℃,Ac3=855℃,and SH-CCT diagram at different cooling rates was plotted.(2)The welding procedure qualification of submerged arc welding method in the flat welding,flux-cored arc welding in the flat welding,the horizontal welding and the vertical welding were carried out according to LR classification society standard.(3)Heated to 900℃and cooled down in the air,then the steel was water cooled to 550℃by flame forming several times.