METHOD FOR JOINING DISSIMILAR METAL PARTS FOR IMPROVED WELDABILITY, WELD QUALITY, MECHANICAL PERFORMANCE

摘要

A method that improves the weldability, weld quality and mechanical performance of components involving concentric parts or non-concentric parts with closed weld seams of dissimilar metals and uses a temperature differential concept on one of the parts or both of the parts to be joined is proposed. This method results in improved weldability, prevents weld cracking both during and after welding, and significantly improves structural performance in terms of static, fatigue, and dynamic strengths. For dissimilar metal joints that are prone to formation of intermetallics, the differential temperature technique can significantly reduce the detrimental effects of intermetallics on mechanical performance of joints, as a result of favorable stress state generated by the temperature differential.

主权项

1. A method of joining dissimilar metal parts with a closed bond line or a closed weld seam, the method comprising:
providing a first member; providing a second member being positioned relative to the first member; preheating the first member to a first temperature that is less than a temperature that results in predetermined degradation of material properties in the first member; maintaining the second member at a second temperature to maintain a predetermined temperature differential (ΔT) between the second temperature and the first temperature; and welding the first member and the second member together while the temperature differential is maintained.