Study on Effect of Tempering Temperature on Microstructure and Properties of Super Martensitic Stainless Steel Welded Joints

Abstract The ultra-martensitic stainless steel ZG06Cr13Ni4Mo, due to its excellent corrosion resistance, good tensile property and weldability, is widely used in many occasions of hydropower, thermal power, nuclear especially as the preferred material for pump impeller. This type has weldability low carbon content, but content reversed austenite weld will lead poor plastic toughness welded joint. effect different tempering processes on microstructure transformation mechanical properties joints was studied. 20 mm thick test plate MIG welding then tempered at 560 °C, 600 640 °C 2 h. results show that after increasing temperature, gradually decreases from base metal transforms lath martensite sorbite; When finest, size grain 0.274 μm. highest 9.39%; In joint, compared with untempered hardness joint area tempering, strength first increases. yield elongation increase.