Optimization of the content of retained austenite in Fe-(0.01-0.045)C-14Cr-(4-9)Ni weld metals for strength-ductility balance

Retained austenite in Fe-(0.01-0.045)C-14Cr-(4-9)Ni weld metals affects strength and ductility, but the two impacts are usually opposite-generally negative impact on strength and positive impact on ductility, although anomalies were found at some low temperatures. The optimum content of retained austenite, therefore, should be determined from the balance of strength and ductility. The strength (yield strength and tensile strength) and ductility, in terms of elongation, of the Fe-(0.01-0.045)C-14Cr-(4-9)Ni weld metals with different contents of retained austenite were investigated in detail within the temperature range of 353-77 K. It was found that elongation improvement is significant at 77 K as well as strength-ductility balance. From the experimental elongation and yield strength, a diagram that determines the optimum content of retained austenite was drawn.