Practice of JCO Welding Process for Cr-Mo Series Heat-resistant Pearlite Steel Pipe

Analyzed is the welding performance of the Cr-Mo series heat-resistant pearlite steel.Addressing the problem of the said steel，i.e.a serous trend to clod crack and reheat crack，the automatic JCO 2-side，3-wire SAW manufacturing process that suits the Cr-Mo series heat-resistant steel pipe is discussed，and the microstructure of the welding joint of the ASTM A 387/A 387M—2006a Class 2 Grade 11（Gr11-Cl2）heat-resistant pipe is analyzed.The analysis result leads to the conclusion that the above mentioned cold crack as developed during welding operation，and the SR cracks as occurred in the welding HAZ and after heat treatment can be prevented by means of techniques namely，using the welding agent as combining the H08CrMoA weld wire and HJ350 flux，properly controlling welding heat input，and keeping the pre-heating temperature for welding as 150℃，the post-heating temperature as 250～300℃，the holding time as 30 minutes，and the post-welding heat treatment temperature as 690～710℃，etc.