Welding process of Q345E steel plate suitable for low-temperature environment in polar region

Abstract

The invention provides a Q345E steel plate suitable for a low-temperature environment in the polar region and a welding process thereof. The impurity content and the grain size of Q345E steel are controlled so that the steel can have good low-temperature impact energy at minus 50 DEG C. During welding, the metallographic structures and the grain sizes of a simulation sample under different linear energy conditions are determined through a welding heat simulation method, and the mechanical property is judged and determined according to the metallographic structures and the grain sizes, so that the appropriate welding linear energy range is determined; then a welding material with the mechanical property indexes meeting the use requirements in the low-temperature environment in the polar region is selected; the test plates are welded by using the selected welding material within the determined welding linear energy range; samples are cut off from the test plates, and the mechanical properties of the samples are detected; and when the mechanical property test result meets the use requirement in the low-temperature environment in the polar region, the welding parameters of the Q345E steel plates suitable for being used in the low-temperature environment in the polar region are determined, and finally welding is conducted according to the determined parameters. The welding joint of the Q345E steel plates welded by the welding process meets the use requirement in the low-temperature environment in the polar region.

Description

technical field [0001] The invention relates to the technical field of mechanical processing; in particular, it relates to a Q345E steel plate welding process suitable for use in polar low-temperature environments. Background technique [0002] The drilling rig components used in the polar low temperature environment are welded by Q345E steel plate. The Q345E steel plate itself has the performance to be used in the low temperature environment of -40°C, but it cannot be used in the polar environment of -50°C. Technological measures need to be taken to improve its low temperature. performance, so that it meets the requirements for use in the polar -50°C environment. At the same time, compared with the original Q345E steel plate, the metallographic structure and mechanical properties of the welded joint will change after the steel plate is welded, and the low-temperature performance will decline to a certain extent. It is necessary to study the welding process of the welded joi...

AI Technical Summary

Problems solved by technology

To determine the appropriate welding process for a certain steel plate, the traditional method is to pre-determine different welding heat and welding materials according to the experience of engineers, actually weld a large number of welding sample joints, and test the metallographic structure and mechanical properties of these joints. Select the corresponding welding process according to the appropriate test results. This type of process test method has a long cycle and high cost

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