A solid welding wire for steel castings of 650°C ultra-supercritical thermal power steam turbines

Abstract

The invention relates to a solid welding wire for steel castings of ultra-supercritical thermal power steam turbines at 650°C, which belongs to the field of welding materials and solves the problem that the deposited metal produced by the existing welding wire cannot meet the mechanical performance requirements of steel castings of ultra-supercritical thermal power steam turbines . The composition of the core wire of the welding wire includes: C: 0.05%‑0.12%, Mn: 0.3%‑0.9%, Si: ≤0.50%, P: ≤0.010%, S: ≤0.01%, Cr: 8.5%‑ 9.3%, Co: 2.5%‑3.5%, W: 2.5%‑3.5%, Ni: 0.05%‑0.25%, Nb: 0.02%‑0.08%, V: 0.12%‑0.32%, B: 0.002%‑0.008% , N: 0.015%‑0.025%. The invention obtains physical and chemical properties similar to the parent metal by adding trace alloy elements and moderately adjusting the content of some elements, and is especially suitable for repair welding and structural welding of ultra-supercritical steam turbine castings, especially for welding of heat-resistant steel MARBN.

Description

technical field [0001] The invention relates to the technical field of welding steel castings of 650°C ultra-supercritical thermal power steam turbines, in particular to a solid welding wire for steel castings of 650°C ultra-supercritical thermal power steam turbines. Background technique [0002] With the large demand for electricity brought about by the rapid development of the national economy in recent years, relevant departments and enterprises urgently need to improve the efficiency of power station construction and operation, reduce costs and take into account environmental protection. Under such conditions, the development of ultra-supercritical thermal power units has become the dominant direction of power station construction. The new martensitic heat-resistant steel has become the focus of development, especially the 9% Cr-3% W-3% Co series heat-resistant steel, which has excellent structural stability and durable strength in the temperature range of 620-650 ° C, ...

AI Technical Summary

Problems solved by technology

[0004] In view of the above analysis, the present invention aims to provide a solid welding wire for 650°C ultra-supercritical thermal power steam turbine steel castings to solve the problem that the deposited metal produced by the existing welding wire is difficult to meet the 650°C ultra-supercritical thermal power steam turbine steel castings. The problem of mechanical performance requirements

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