Welding material for austenitic heat-resistant steel, and welded metal and welded joint each using same

Abstract

Disclosed is a welding material for austenitic heat-resistant steel, which has a chemical composition that contains more than 0.05% but 0.18% or less of C, 0.5% or less of Si, 1.5% or less of Mn, 40-50% of Ni, 20-25% of Cr, more than 8.0% but 13.0% or less of W, 0.01-0.2% of Ti, more than 0.03% but 0.20% or less of N and 0.01% or less of Al, and additionally if necessary, less than 0.60% of Nb, with the balance made up of Fe and impurities, while controlling O, P and S contained as impurities to 0.02% or less, 0.008% or less, and 0.005% or less, respectively. The welding material for austenitic heat-resistant steel exhibits excellent high-temperature cracking resistance during the welding. A welded metal that has high-temperature cracking resistance during the welding, stress relaxation cracking resistance when in use for a long period of time at high temperatures, and good creep strength can be provided using the above-described welding material. In addition, a welded joint can be provided, using the above-described welding material, from a base that has excellent creep strength at high temperatures and a welded metal that has high-temperature cracking resistance during the welding, stress relaxation cracking resistance when in use for a long period of time at high temperatures, and good creep strength.

Description

technical field [0001] The invention relates to a welding material for austenitic heat-resistant steel, a welding metal and a welding joint using the welding material. Specifically, it relates to a welding material suitable for welding austenitic heat-resistant steel, which is used in boilers for power generation, etc. Austenitic heat-resistant steels in equipment used at high temperatures. Background technique [0002] In recent years, from the viewpoint of reducing the environmental load, the operating conditions of power generation boilers and the like have been increased to high temperature and high pressure globally, and materials used in power generation boilers and the like have been required to have more excellent high temperature strength. [0003] As a material satisfying this requirement, for example, Patent Document 1 proposes an austenitic heat-resistant steel that has excellent creep strength in a high-temperature range of 700°C or higher by including a large ...

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