| 摘要 |
PROBLEM TO BE SOLVED: To provide a weld joint recovering the corrosion resistance of the area heated at high temperature of approx. 1,100°C or higher as the highest arrival temperature in the weld heat affected zone formed by welding a duplex stainless steel, and having excellent corrosion resistance in a corrosive environment.SOLUTION: A weld joint comprises the duplex stainless steel material which contains 20 mass% or more of Cr and 0.1 mass% or more of N in a chemical composition, comprises two phases of ferrite and austenite, and satisfies the expression: 0.0092×Q/h≤L≤0.029×Q/h-1, when defining the board thickness of the duplex stainless steel material as h (mm), and defining the distance between the melting boundaries of re-welded metal and initial weld joint after re-welding the welded metal with the heat input amount Q (J/mm) as L (mm).SELECTED DRAWING: Figure 3 |
