Research on Welding Process for L245/S30403 Straight Clad Pipe

Investigated in the article are the factors affecting corrosion resistance of the clad pipe weld joint.Taking manufacture of the Φ508 mm×（8+2）mm×6 000 mm L245/S30403 straight weld clad pipe as an example，the main aspects concerning production of the straight clad pipe are detailed， including welding method， welding material selection，design of the welding bevel type and relevant parameters，and metallographic structure analysis and property testing of the finalized pipe.The result of the analysis reveals that the major factors affecting corrosion resistance of the clad pipe weld joint include transitional layer， penetration ratio， intergranular corrosion， and content of δ ferrite.Therefore to reduce the penetration ratio via proper control of heat input is the primary principle for welding the straight clad pipe.And furthermore，due to the difference of plastic modules between the base layer and the clad layer，in case of making the clad pipe with the expanding process，great care has to be taken，while proper stress-release methods like aging or mechanical process should be adopted.