Abnormal Hardness in Welding Heat Affected Zones of F91 Forged Valves (Part Two)
3. Measures To improve the hardness and metallographic structure of F91 low alloy steel after welding, combined with the above welding process analysis, the following measures are proposed. (1) Welding processes According to DL/T 869-2012 "Welding Technical Regulations for Thermal Power Plants", the welding process and evaluation are compiled, and the welding operation is carried out according to the welding process; the preheating of welding and the temperature between welding...