Metallurgical Considerations in the Manufacture of Clad Heads
Manufacture of clad pressure vessels frequently requires elevated temperature forming of heads. For some clad metal combinations, there are conflicts between the ideal hot metal working parameters for the cladding metal and base metal. Further, bi-metal interactions of some metal combinations at elevated temperatures can result in significant deterioration of interface strength and ductility. Improper forming conditions can result in loss of cladding metal corrosion properties, inappropriate base metal mechanical properties, and/or clad separation. NobelClad has extensive experience with the conventional clad metal combinations and has established forming parameters which result in reliable corrosion resistance of the cladding metal, Code compliant base metal, and absence of interface problems. Critical issues and concerns are discussed and case histories and test results from representative clad head forming projects are presented.