Welding method for stainless steel composite board pressure vessel shell and insert-type stainless steel connecting pipe

Abstract

The invention discloses a welding method for a stainless steel composite board pressure vessel shell and an insert-type stainless steel connecting pipe. The method comprises the steps of a) arranging a pipe hole of the stainless steel connecting pipe in a stainless steel composite board pressure vessel shell, and manufacturing a pipe hole wall to be a primary bevel with a K shape or a single V shape; b) performing bead-welding on a primary bevel surface by using high chromium nickel stainless steel welding rods to form a transition isolating layer with certain thickness, so as to form a secondary bevel; c) carrying out stress-relief heat treatment on the stainless steel composite board pressure vessel shell after the bead welding; and d) welding corner connecting joints between the stainless steel connecting pipe and the stainless steel composite board bead-welding layer by using stainless steel welding rods with different materials according to a stainless steel composite layer on a composite board. As the transition isolating layer with the certain thickness is firstly bead-welded on the primary bevel of the basic layer side of the stainless steel composite board by using the high chromium nickel stainless steel welding rods, and then the corner connecting joints are welded by the stainless steel welding rods, so that carbon steel and low alloy steel components are transited into stainless steel components, the welding line plasticity can be transited from low to high, cracks are avoided, and the using performance is reliable.

Description

technical field [0001] The invention relates to a welding method for a pressure vessel shell made of a stainless steel composite plate and a plug-in stainless steel connecting pipe. Background technique [0002] Stainless steel clad plates are widely used in the manufacture of pressure vessels in power construction, petrochemical, pharmaceutical, light industry and other industries, and in power construction, petrochemical, pharmaceutical, light industry, automobile and other industries. The base layer of the stainless steel clad plate (carbon steel, low alloy steel, etc.) is welded to the fillet joint of the stainless steel pipe, usually using high-chromium-nickel welding consumables (such as A302, A042, A062, etc.) for welding. First make a K-shaped or single V-shaped groove on the base layer 2 of the stainless steel composite plate shell, and then make a single-sided V-shaped groove on the stainless steel clad layer 1. The groove extends 2mm into the carbon steel base lay...

AI Technical Summary

Problems solved by technology

Nickel-based electrodes have good plasticity and have considerable plastic deformation storage energy, which can effectively avoid cracks. However, due to the large difference between the components of nickel-based electrodes and carbon steel or stainless steel, the weld performance is far lower than that of the base metal. The performance of welded joints after heat treatment is not ideal, and the occurrence of welding cracks cannot be completely eradicated; in addition, high-priced nickel-based electrodes also increase welding costs

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