Study On Arc And Procedure Of Welding With Water

Factors, such as pipeline aging and water hammering, can cause the leakage, even detonation of water supply pipelines tube, seriously affecting people’s life and company’s production. Water supply pipeline leakage causes the waste of water, bring large economic loss to the society. Online welding repair technology can effectively repair leaking pipes, reducing pipeline leakage losses. In this paper, the low carbon steel was welded under different environment, studying on the welding arc and procedure of welding with water. Test equipments such as metallographic microscope, SEM, diffusion hydrogen determinator, mechanical testing machine, microhardness tester, data acquisition function recorder, oscilloscope, were used to search the properties such as microstructure, manufacturability, mechanical property of welded joints under different welding conditions.This paper study the effects of different welding environment on arc stability. The results show that different welding environment impact on the welding arc. The arc stability of welding in air is the best, welding in changeless running water is the second, better than welding in changing running water and welding in still water. When water pressure increases, the stability of welding arc become bad; Arc of welding in still water’s bubble grew up periodically-burst-regrowth, led to the decrease of the arc stability.Studied the conditions of welding with water, welding procedure and welding environment on the influence of the weld. Results show that Compared with welding in air when welding with water the weld deformation is poor, shallow depth of penetration. Water under the condition of low pressure, high fusion width, and penetration and reinforcement increases with the increase of welding current; With high pressure water, when welding the weld is difficult, using broken arc spot welding method to deal with the smaller leak and using the method of surfacing welding cover method to deal with the high pressure leak, able to quickly and efficiently block funnelled; Using continuous welding, broken arc spot welding and shrinking joint welding method, which can effectively repair the wide high pressure leak.With water under the condition of welding seam organization and the research results show that the performance of welded joint with water cooling rate is far higher than that of welding in air, water absorbing material on the surface of the weld and the impact of water environment will cause the higher content of hydrogen diffusion. Bring water welding joint organization obviously refined, the welding heat affected zone coarse grain zone formation of lath martensite hardened tissue, such as weld metal group is mainly composed of ferrite. Welded joint with water the highest microhardness welding heat affected zone is located in the coarse grain area, welding with water’s heat affect zone and welded joint weld hardness is higher than welding in air. With water weld penetration is shallow, bearing capacity is low, the tensile fracture is located in the weld, fracture form for ductile fracture and mixed fracture of brittle fracture.