Online process for improving impact toughness of welding heat affected zone

Abstract

The invention relates to an online process for improving the impact toughness of a welding heat affected zone. The online process adopts the technical scheme that the compressed gas is directly blown at the position of a welding joint which is 20-1200 mm away from a welding electric arc in the welding process of a steel product; the blowing time is 2-120 s; and the distance between the position of the blown welding joint and the welding electric arc is kept unchanged and synchronously moves forwards along with the welding electric arc. The compressed gas is air, the pressure of the compressedgas is 0.5-3.0 MPa; the flow rate of the compressed gas is 5-30 L / min; the steel product is one of low carbon steel, medium carbon steel, low alloy steel, medium alloy steel and high alloy steel; andthe welding joint is one of welding points formed by welding methods of electric arc welding, submerged-arc welding, gas shielded welding and argon tungsten-arc welding. The online process has the characteristics that the online process is simple, is convenient to operate, has low cost and requires no additionally-arranged special equipment. With the adoption of the process, the impact toughness of the welding heat affected zone can be improved by 60-525 percent.

Description

technical field [0001] The invention belongs to the technical field of welding. Specifically, it relates to an online process for improving the impact toughness of a welding heat-affected zone. Background technique [0002] With the rapid development of the global economy, the demand for large-scale equipment construction is increasing, and high-strength steels, even ultra-high-strength steels, are continuously invented, developed and produced, such as oil storage tanks, offshore platforms, oil and gas High-strength steel for pipelines, as well as fine-grained high-strength steel and ultra-high-strength steel. These high-strength steels and ultra-high-strength steels will play a great role in the construction of large-scale equipment and in reducing construction costs. However, after the high-strength grade steel and ultra-high-strength steel produced by advanced smelting technology, perfect rolling process and heat treatment process are welded, embrittlement occurs in the...

AI Technical Summary

Problems solved by technology

[0006] The method of developing new steel types requires a solid theoretical foundation, and a large number of experiments are carried out on this basis to realize it. The cost is high and the research and development cycle is long; the use of special processing methods requires special processing equipment and requires secondary processing. One-time labor, increased labor intensity, increased process time, and increased production costs; using water-cooled forced cooling, the gas-electric vertical welding equipment used is expensive, and its price is 6-10 times that of ordinary welding machines, and can only be used for one time. A specific welding method and a vertical welding position, so it is highly restrictive and cannot be widely used

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