Difficulties and its counter measures on the welding of 07MnNiMoVDR steel of 2000 m~3 propylene spherical tank in winter

The 07MnNiMoVDR high-strength steel was applied the 2 000 m3 propylene spherical tank.Welding of high-strength steel is relatively complicated in winter.So effective protection measures should be taken.Based on analyzing the welding performance of 07MnNiMoVDR Steel and difficulties,effective welding procedures and counter measures such as preheating,weld head input control,interpass temperature control,elimination of hydrogen heat treatmeat after wealding,key points of welding shall be taken.Propylene spherical tank was Successfully constructed in winter.It Proved the rationality of the project and accumulated some experience for the welding of the steel in the future.