Surface treatment technology of titanium alloy bucket welded joint

Abstract

The invention discloses a surface treatment technology of titanium alloy bucket welded joint. The surface treatment technology comprises the following steps: pre-treating a titanium alloy bucket weld joint, using ultrasonic waves to impact the weld seam, weld toe, and heat affected zone until the average particle size of the grains in the space from the surface to a depth of 160 [mu]m of the weld seam, weld toe, and heat affected zone is not more than 200 nm; and carrying out a thermal treatment. After a titanium alloy bucket welded joint is processed by the provided technology, the surface tissues of the weld joint are converted into a stable refined layer, the surface roughness is reduced, the surface hardness is increased, the transition in the weld toe zone is smooth, moreover a high residual compressive stress exists on the processed surface, and thus the plasticity, anti-fatigue performance, and ware-resistant strength of the weld joint are all greatly improved.

Description

technical field [0001] The invention belongs to the field of welding technology, in particular to a surface treatment process for welded joints of titanium alloy buckets. Background technique [0002] Now with the change of industrial structure and the development of science and technology, advanced welding structure is an effective way to reduce material consumption and reduce structural quality. Titanium and its alloys have excellent corrosion resistance, low density, high specific strength, good toughness and weldability, and are widely used in aviation, aerospace, shipbuilding, chemical and other industrial sectors. [0003] Titanium has high melting temperature, large heat capacity, large resistivity, and lower thermal conductivity than metals such as aluminum and iron, so the welding pool of titanium has a higher temperature and a larger size of the pool, and the metal in the heat-affected zone is at high temperature. Therefore, it is easy to cause the overheating ten...

AI Technical Summary

Problems solved by technology

[0003] Titanium has high melting temperature, large heat capacity, large resistivity, and lower thermal conductivity than metals such as aluminum and iron, so the welding pool of titanium has a higher temperature and a larger size of the pool, and the metal in the heat-affected zone is at high temperature. Therefore, it is easy to cause the overheating tendency of the welded joint, so that the grain becomes very coarse, the plasticity of the joint is significantly reduced, and the fatigue resistance and wear resistance performance are reduced.