Welding material and a method of producing welded joint

An iron based alloy welding composition consisting essentially of, by mass %:

• at most about 0.20% of C;
• from about 6.0 to about 16.0% of Cr;
• from about 6.0 to about 16.0% of Ni;
• at most about 1.0% of Si;
• at most about 2.5% of Mn;
• at least one of (a) at most about 4.0% of Mo and (b) at most about 1.0% of Nb;
• balance Fe and inevitable impurities,
• wherein the composition has a martensitic transformation starting temperature in a range of at least about 0° C. and less than about 170° C.

A method of producing a welded joint, in which materials to be welded are welded to each other using a welding material so as to form a welded joint, comprising the steps of:

• employing a low alloy steel material as a material to be welded;
• forming a weld metal by welding;
• and
• adjusting composition and welding conditions of the welding material, according to the composition of the material to be welded, such that the weld metal is an iron alloy composition containing at most about 0.20 mass % of C, from about 3.0 to about 13.0 mass % of Cr, from about 3.0 to about 13.0 mass % of Ni and has a martensitic transformation starting temperature in about a range from about 50° C. to less than 360° C.

A welded joint, in which materials to be welded are welded to each other by using a welding material, comprising:

• a low alloy steel material as material to be welded;
• and
• a weld metal formed by welding,
• wherein the weld metal is an iron alloy composition containing at most about 0.20 mass % of C, from about 3.0 to about 13.0 mass % of Cr, from about 3.0 to about 13.0 mass % of Ni and has a martensitic transformation starting temperature in range of at least 50° C. and not more than 360° C., and the weld metal is a composition which exhibits a temperature-elongation curve in which the weld metal is in an expanded state, at room temperature, as compared with a state thereof when martensitic transformation started.