Weld joint and weld material thereof

Abstract

A weld joint, characterized in that both of a base material and a weld metal have a chemical composition that C: 0.01 to 0.45%, Si: more than 1 % and not more than 4 %, Mn: 0.01 to 2 %, P: 0.05 % or less, S: 0.01 % or less, Cr: 15 to 35 %, Ni: 40 to 78 %, Al: 0.005 to 2 %, N: 0.001 to 0.2 % and Cu: 0.015 to 5.5 %, Ti: a content satisfying the following formula (1): {(Si - 0.01) / 30} + 0.01Cu <= Ti <= 5 (1) wherein an element symbol in the formula (1) means the content (mass %) of the element, and the balance: Fe and impurities. The base material and the weld metal may further contain one or more of Co, Mo, Ta, W, V, Zr, Nb, Hf, B, Ca, Mg and REM.

Description

technical field [0001] The invention relates to a welded joint of a component used in a high-temperature corrosive environment and its welding material. Examples of components used in high-temperature corrosive environments include containers, reaction tubes, and parts used in heat-exchange hydrocarbon reformers and waste heat recovery devices in GTL facilities such as petroleum refineries and petrochemical facilities. . Background technique [0002] Heat exchange for recovering waste heat is often used in order to improve energy efficiency in reforming equipment in petroleum refining and petrochemical facilities, ammonia production equipment, and hydrogen production equipment using petroleum as a raw material. On the other hand, it is conceivable that the demand for clean energy such as hydrogen and methanol gas will increase significantly in the future, and the reformer that is indispensable for their manufacture is required to be large-scale, high in thermal efficiency, ...

AI Technical Summary

Problems solved by technology

[0010] The welded joint disclosed in Patent Document 1 has a low Si content, so it is difficult to use it in an environment where metal powdering occurs

In the welded joint disclosed in Patent Document 2, when a minimum amount of Si is added to ensure metal powdering resistance, weld solidification cracks occur, making it difficult to ensure excellent weldability