Development of Techniques for Controlling Warpage and Residual Stresses in Welded Structures

摘要

The document represents a series of experimental studies performed to determine the feasibility of alleviating warpage and residual stresses in welded aluminum structures applicable to the Saturn program. The studies were performed by altering the thermal pattern during the welding operation using local applications of cryogenic liquids and auxiliary heat to counterbalance thermal stresses produced by welding. Results of the work have definitely demonstrated that such control is possible. For some welded samples, warpage has been reduced to zero, and residual stresses have been reduced to values as low as 5 percent of those present in conventionally welded samples. Sufficient data has not yet been accumulated for establishing optimum thermal patterns for specific weldments, but such patterns should be established in relatively short time. (Author)