Thick steel plate welding process at low-temperature environment

Abstract

The invention discloses a thick steel plate welding process at a low-temperature environment, comprising the following steps: forming a beveled edge at the weld of a steel plate; cleaning a weld joint region and surrounding region within 30mm, and polishing the steel plate; placing connectors of the steel plate in an abutting joint manner and starting to preheating the steel late in such a manner that the surface of the weld is heated, wherein the heating region is two times thicker than a thicker plate among welded connectors, and is not smaller than a region with the radius of 100mm; performing positioned welding at intervals of 300-600mm, wherein the thickness of the positioned welding is not larger than 1 / 2 the design size of the weld joint, the length of the positioned welding is larger than 40mm; selecting shielded metal arc welding to assemble and position and selecting gas shielded flux cored wiresemi-automatic welding to weld a main weld joint, wherein dispersed, symmetric, multi-layer multi-beadwelding methods are adopted to perform the welding; the weld joints are protected for over 5 minutes in protective gas after the welding is finished, and the weld joints are wrapped by a layer of thermal insulation rock wool which cannot be removed until the next day. According to the thick steel plate welding process disclosed by the invention, the process is simple, such two factors as the thick steel plate and the low-temperature welding are taken into consideration at the same time, so that the welding can have an excellent performance under a severe condition, and the thick steel plate welding process has a better applicability and an excellent welding performance.

Description

technical field [0001] The invention relates to the field of daily necessities, in particular to a low-temperature environment welding process for thick steel plates. Background technique [0002] The welding process is a very important process in the construction of basic steel structures. The quality of welding greatly affects the service efficiency and life of infrastructure. In addition to being related to the welding base metal, the welding machine is also closely related to the external environment and other factors. The problem solved by the welding process is to take measures for the specific welding base material in a specific environment to obtain ideal stress characteristics and structural characteristics. [0003] A large number of tests have shown that the main cause of weld brittle fracture at low temperature, especially the brittle fracture effect of notch effect in the structure is more serious. When the project needs to be constructed in winter, when the am...

AI Technical Summary

Problems solved by technology

Therefore, welding operations in low temperature environments must solve the problem that the reliability of welds will be severely weakened by temperature conditions.