scope:

A multitask experimental study was conducted to provide the petroleum industry with solutions to recurring incidents of cracking in the application of welded 1¼Cr-½Mo steel for hydrogen processing equipment. The principal objective was to develop recommendations for the elimination of cracking that occurred during fabrication or early in operating life, was associated with repairs or was found after extended service exposure at elevated temperature. Vessel and equipment experience has shown that the majority of weld cracking problems have occurred at temperatures in excess of 850°F. Further, little or no problems have been found for operation at temperatures below 800°F. Thus, a cutoff temperature of 825°F has been suggested for invoking the precautions, considerations and recommendations regarding the potential for coarse grained weld HAZ (CGHAZ) cracking in 1¼Cr-½Mo steels. The objectives of this research report were to: determine what compositional and other material issues influence cracking; evaluate controlled deposition repair techniques; determine the suitability of low carbon filler materials; and understand the role of fabrication and welding practices on susceptibility to cracking. Publication of this document - WRC Bulletin No. 411 was sponsored by The Welding Research Council. The work presented in this document was sponsored by the Materials Properties Council, Inc., and the the American Petroleum Institute