PREDICTION OF COOLING TIME FOR FERRITE-AUSTENITE TRANSFORMATION IN DUPLEX STAINLESS-STEEL

Study has been carried out aimed at predicting the cooling time from 1 200 to 800 degrees C (t(12/8)) of are welds in stainless steel using an existing heat flow model and direct measurement of the weld thermal cycle. The properties of welds in austenitic-ferritic duplex stainles s steel depended on the delta (delta) ferrite content of the weld meta l (WM) and the heat affected zone (HAZ). The t(12/8) was the major coo ling parameter relating to the delta-ferrite content. It was shown tha t the travel speed and the distribution of the heat source had negligi ble effect on the value of t(12/8) in a practical welding situation. T he proposed equation predicted t(12/8) With an error of approximately 15% relative to experimental measurement.