Roll Seam Welding Method of Large Diameter Process Roll Rolled by Plate

Abstract

The invention discloses a method for welding roll gaps of a large-diameter technical roller coiled by plank stuffs. Roll gap grooves comprise a V-shaped groove and a flat-bottom trapezoidal groove with a truncated edge or a U-shaped groove with the truncated edge so that the consistency of the groove size is guaranteed; an assembly is used for combining and aligning the roll gaps so that an edge offset is not generated; two ends and a middle part of a roller are welded with rib plates; before welding, partially pre-heating roller to more than 200 DEG C and then welding; respectively controlling heights of the rib plate in the middle and welding legs of the rib plates at two sides to 8 mm and 10 mm; cleaning greasy dirt and corrosion impurities of the whole groove and the inner surfaces oftwo sides in a range of 50 mm so that the cleaning of the welding surface is guaranteed; utilizing a small-hole welding way of the plasma welding to completely weld the welding line groove with the truncated edge for one time without filling welding wires; conventionally welding the U-shaped groove to satisfy fault detection requirements; after welding, slowly cooling. The method provided by the invention guarantees the consistency among organization and hardness of the welding line and the roller and improves the production quality of the technical roller, so that the quality of the rolled belt steel is reliably guaranteed.

Description

technical field [0001] The invention relates to a roll seam welding method of a large-diameter process roll rolled by plate materials. Background technique [0002] Large-diameter process rolls are the general term for the tension rolls, top rolls, steering rolls, deburring rolls and other rolls used in the steel rolling production line. The surface is subjected to quenching heat treatment and hard layer spraying to adapt to the operating conditions of the process roll. After conventional welding of the large-diameter process roll seam rolled by sheet metal, the structure and hardness of the weld material at the weld position after process roll quenching heat treatment are significantly different from those at other positions on the roll body, especially at the weld fusion line and the influence of welding heat. In the area, there are serious inhomogeneities in structure and material composition. During the subsequent heat treatment, spraying and other processes, this inhom...

AI Technical Summary

Problems solved by technology

After conventional welding of the large-diameter process roll seam rolled by sheet metal, there are obvious differences in the microstructure and hardness of the welding material at the weld position of the process roll after quenching heat treatment and other positions on the roll body, especially in the weld fusion line and the influence of welding heat. In the area, there are serious inhomogeneities in structure and material composition. When heat treatment, spraying, etc. Cracks appear during quenching at the seam position, seriously affecting the manufacturing quality of the rolls, and thus affecting the quality of the rolled strip

The direct cause of the above phenomenon is the weld seam caused by the welding process and the hardness difference between the welding heat-affected zone and the base metal. The performance of the seam itself and the performance after quenching cannot match the roll body

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