Welding method for steel structure in environment of -15 DEG C to 35 DEG C

Abstract

A welding method for a steel structure in an environment of -15 DEG C to 35 DEG C includes steps: preparation before welding, welding, heat treatment after welding, weld testing and welding defect treatment, wherein preparation before welding includes selecting welding material, cleaning and preheating before welding, and determining welding parameters; implementing immediate heat treatment after welding for at least 1 hour with a postheat temperature of 180-230 DEG C; under the circumstance of power-off, immediately coating the weld surface with at least one layer of insulation rock wool, namely at least in thickness of 35 mm, to implement heat preservation and slow cooling after welding as an emergency measure; making sure that cooling speed is no larger than 10 DEG C per minute, namely, the time that the temperature of the welding material falls at 0 DEG C is no less than 20 minutes; and preserving the insulation rock wool until the next day. The method solves the technical problem of welding the steel structure in an environment of ultralow temperature, is energy-saving, environment-friendly, convenient in operation, easy in population and standardization, and work efficiency and quality of the welding are guaranteed.

Description

technical field [0001] The invention relates to a welding operation device or method related to the international patent classification B23K, especially a welding method for a steel structure in an environment of -15°C to -35°C. Background technique [0002] In the known technology, with the popularization and application of building steel structure engineering in large areas, there are low temperature and other environmental conditions that seriously affect normal operations in some areas. For example, in terms of climate conditions in Northwest China, the high temperature in summer reaches 35°C, and the low temperature in winter is -40°C. About ℃, the basic wind pressure W0=0.90KN / m 2 , the maximum wind speed is 52m / s; the direct characterization of the hazards of low temperature welding of steel structures to the weld metal is the occurrence of cracks and brittle fracture under working conditions. If the control is not good, the welding quality will decline or even cause ...

AI Technical Summary

Problems solved by technology

[0005] Although the above technical content has yet to be verified by practice, it is better than nothing; however, for environments with lower temperatures, such as the long winter in Northwest China and the typical low temperature as low as -15°C to -35°C, due to the welding of steel structures in this case There is no technical solution for the operation, and the existing technology generally only chooses to stop the operation, so it still causes a huge waste of construction time

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