Welding method for prolonging service life of high-strength metal shell

Abstract

The invention discloses a welding method for prolonging service life of a high-strength metal shell, which adopts high-strength anti-wearing steel CiNiMo as a welding substrate. The welding method comprises the following steps of: preparing before welding, carrying out tack welding, pre-heating a welding piece, carrying out welding construction, polishing and carrying out nondestructive testing. The welding method disclosed by the invention is suitable for welding a large-sized piece of low-middle carbon alloy high-strength steel; the welding production rate is high and the anti-cracking performance is good; the welding deformation is small; the welding method has the advantages that selected materials are reasonable and have higher strength; welding current is controlled in a certain range and the occurrence possibility of crack defects is reduced; and with the adoption of the welding method disclosed by the invention, hydrogen removing treatment is carried out after the welding, residual hydrogen in a welding connector is dispersed and escaped in time, and the generation of delaying cracks is reduced.

Description

Technical field [0001] The invention relates to a welding method, in particular to a welding method for prolonging the service life of a high-strength metal shell. Background technique [0002] With the continuous improvement of the domestic comprehensive coal mining mechanization level, the reliability requirements for high-power shearers are also getting higher and higher, especially for the materials and mechanical properties of the coal mining box body and rocker arm shell. Claim. However, the existing high-power shells (rocker arms) mostly use ZG25MnNi and ZG270-500 ordinary strength steel. Although the comprehensive mechanical properties of these two materials are relatively good, their normalizing hardness is relatively low, and the strength is also Not high, the current high-strength coal mining and harsh working conditions are becoming more and more unsuitable, especially the shell welding part is prone to cracks, water leakage, oil leakage soon after use, and serious s...

AI Technical Summary

Problems solved by technology

However, most of the existing high-power shells (rocker arms) use ZG25MnNi and ZG270-500 ordinary strength steel. Although the comprehensive mechanical properties of these two materials are relatively good, their normalizing hardness is relatively low, and their strength is also low. Not high, in the current high-intensity coal mining and harsh working conditions are becoming more and more unsuitable, especially the welded parts of the shell are prone to cracks, water leakage, and oil leakage soon after use. Arm) parts even have quality problems such as deformation and ear twisting off, which greatly shorten the service life of the shearer shell

[0003] In addition, the welding process parameters used in the past are not good, the strength of welding consumables is not enough, the welding current is too large, etc., which often cause defects such as weld cracks, slag inclusions, and undercuts.

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