Hot ductility, as revealed the values of reduction in area at the fracture surface tested at high temperatures on the weld thermal cycles, was studied on austenitic stainless steel weld metals by means of a reproducing apparatus of weld thermal cycles.
Five weld metals, including type 308L, 347 and 316, were tested in this study. A round bar tensile specimen made from multiple pass weld, was heated rapidly up to the peak temperature of 1350°C and then broken at each temperature of 800, 1000, 1100, 1200 and 1300°C both on heating and cooling along the thermal cycle, respectively.
From the tests, hot ductility curves, expressed as percent reduction in area at fracture as a function of the testing temperatures were obtained for each weld metal.
From the values of reduction in area as measured both on heating and cooling at 1200°C, hot ductility rating about these weld metals was determined as the following order.
On heating-308L [347(A), 347(B), 316] 347(C)
On cooling-308L [347(A), 347(B)] 316, 347(C)
Among the test weld metals, the hot ductility of type 308L was the most superior, while that of type 347(C) containing no ferrite was the poorest on the contrary.
Furthermore, the comparison was made between hot ductility and Fisco cracking test results for the test weld metals. A close relationship was found between the two, then the hot ductility was assured to be effective extensively as a measure of hot cracking susceptivility of austenitic stainless electrodes.
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