Marine engineering large thick steel plate submerged arc welding process method in low-temperature environment

Abstract

The invention belongs to the field of welding, in particular to a process method applicable to marine engineering large thick steel plate submerged arc welding in low-temperature environment, which comprises a welding method, welding material selection, a welding order, a welding process and the selection and control of various welding process parameters. The method renders with carbon dioxide gas protection welding, and fills and faces through an automatic submerged arc welding; stops welding when the welding reaches more than two thirds of the thickness of a large groove during the welding process, clears chips on the back side and completes the welding of the other side; finally completes the welding of the first side; strictly controls all relevant process parameters of the welding during the welding process, and solves the problems of poorer anti-crack toughness of welding seams and heat affected zones caused by too high cooling speed of the welding seams and too high temperature; can ensure good anti-crack toughness of a welding seam connector without heat treatment after welding; and can meet the requirements of welding of an E36 plate with the thickness of 35 to 77mm under the working environment at the temperature of above -30DEG C, simplifies the production process, shortens the production cycle and reduces the cost.

Description

Technical field: [0001] The invention belongs to the field of welding, and in particular relates to a submerged-arc welding process for large-thick steel plates in marine engineering in low-temperature environments. Background technique: [0002] At present, with the continuous development of offshore oil development to cold seas and deep seas, the application of domestic E36 thick steel plates in the offshore shipbuilding industry is becoming more and more widely used, and the applicable temperature for welding products is also getting lower and lower. Traditional thick plate welding During the process, welded joints tend to generate more residual stress, which affects the performance of the weld. In order to eliminate the residual stress after welding, the common process is to perform post-weld heat treatment on the weld, but post-weld heat treatment consumes a lot of manpower and material resources, and the construction period is long. , high cost; according to the standa...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the problem that the existing large thick steel plate weld seam needs to carry out post-weld heat treatment to cause the production cost to increase, and to provide a kind of process method suitable for submerged arc welding of large thick steel plate in low temperature environment ocean engineering. , welding materials, using reasonable welding specifications, strictly controlling the welding process, no need for post-weld heat treatment, to obtain welded joints with excellent performance, passed the CTOD test at -30 °C, and obtained good test results. Working temperature at -30 °C The above 35-77mm E36 grade thick plate can completely adopt this process, eliminating the need for post-weld heat treatment on the weld, improving production efficiency and saving production costs

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