Methodology for Prediction of Microstructure and Mechanical Properties of the Heat-Affected Zone of a Joint of a High-Strength Steel Welded in Different Media

A technique for through prediction of microstructure and mechanical properties of metal in the heat affected-zone is suggested. It is based on calculated thermal cycles, diagrams of anisothermal decomposition of austenite and dependences of mechanical properties on the cooling time or the cooling rate. An analytical relationship between the cooling time in the specified temperature range and the cooling rate at the specified temperature is presented. The stages of the technique are considered for an example of welding of a structural steel in air and under water. Satisfactory agreement between the calculated and experimental thermal cycles and hardness distributions is demonstrated.