1980 Volume 49 Issue 1 Pages 35-38
HK-40(0.4C-25Cr-20Ni)centrifugal cast steel pipes have been used for reforming and cracking tubes in the reaction furnace for the petro-chemical industry.
The authors have studied the application of the plasma arc welding to the circumferential joint of those pipes and developed the proper programming as to the start of weld, formation of back bead, crater treatment etc. and previously reported about it.
As these pipes are used in the atomosphere under high pressure and temperature, the properties of the welded joint must show as same excellent heat resistance as base metal.
So the authors investigated properties of welded joint by this plasma arc welding and confirmed that the joint shows more excellent properties than TIG.
This time, this welding method was applied for joining of cracking tubes which were used for producing ethylene.
The joint performance in service is reported in this paper.
