Non-preheating strength gradient matched welding technology for low-alloy high-strength steel with yield strength of 800MPa

Abstract

The invention provides a non-preheating strength gradient matched welding technology for low-alloy high-strength steel with the yield strength of 800MPa, which belongs to the field of the non-preheating welding technology for the low-alloy high-strength steel. The welding technology mainly adopts welding wires with the tensile strength of 500MPa for backing welding and welding wires with the tensile strength of 800MPa for padding and cosmetic welding. The technology mainly solves the technical problem that in the background art, as backing welded joints in a high restraint-intensity welding structure have higher tensile strength, cracks can not be thoroughly eliminated under a non-preheating condition. The technology is used for the non-preheating high-quality welding for the low-alloy high-strength steel with the yield strength of 800MPa.

Description

technical field [0001] A non-preheating strength gradient matching welding process for low-alloy high-strength steel with a yield strength of 800 MPa belongs to the field of low-alloy high-strength steel non-preheating welding technology, and in particular involves the use of welding wire with a tensile strength of 500 MPa for bottom welding and a tensile strength of 800 MPa. Filler and cap welding. Background technique [0002] With the rapid development of the machinery industry, welded structures are becoming larger and lighter. Due to its good weldability, excellent formability and low manufacturing cost, low-alloy high-strength steel is widely used in pressure vessels, vehicles, bridges, construction, engineering machinery, mining machinery, agricultural machinery, textile machinery, marine It has become one of the most important structural materials in large-scale welded structures in the fields of structures, ships, electric power, petrochemicals, military products, ...

AI Technical Summary

Problems solved by technology

The traditional low-strength matching welding process can reduce the welding preheating temperature of low-alloy high-strength steel, but it is necessary to increase the weld reinforcement to ensure the strength requirements of the overall structure. This method not only easily causes stress concentration at the weld toe, but also makes manufacturing difficult. increase and change the geometric dimensions of the welded structure at the same time, how to control the geometric dimensions of the weld reinforcement has become a bottleneck in production

[0006] For low-alloy high-strength with a yield strength of 800MPa, low-strength matching can solve the problem of low-alloy high-strength non-preheating to a certain extent. Usually, the tensile strength of the bottom welding wire is higher, such as the tensile strength of 600MPa or 700MPa. In welded structures with high hardness, this kind of root welding cannot completely eliminate cracks without preheating.

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