Method for welding stainless steel seawater filter element compositely through laser spot welding and vacuum brazing

Abstract

The invention discloses a method for welding a stainless steel seawater filter element compositely through laser spot welding and vacuum brazing. The method comprises the steps that surface pretreatment is carried out on an inner framework and the to-be-welded portion of a filter net of the stainless steel seawater filter element, the to-be-welded portion is fixed through a clamp, the to-be-weldedportion is fixed to the surface of the inner frame according to the circle number of the filter net through laser spot welding, the to-be-welded face is coated with brazing filler metal, finally, vacuum brazing is adopted for carrying out brazing on to-be-welded positions except for the laser spot welding position, and therefore welding of the stainless steel seawater filter element is completed.According to composite welding of laser spot welding and vacuum brazing, during steel connection, since the temperature is low, the problem that nitride, carbide and carbonitride are produced at a joint so as to reduce performance can be effectively prevented, the structure performance changing problem is avoided, and the welded joint has no defect, is high in cleanliness and excellent in performance.

Description

technical field [0001] The invention relates to a stainless steel seawater filter element in the field of seawater purification, in particular to a method for composite welding of a stainless steel seawater filter element by laser spot welding and vacuum brazing. Background technique [0002] As an important component of seawater purification equipment, the seawater filter element is composed of an inner skeleton, a filter layer protection net, a filter net, and an outer protection net. The main connection methods include fusion welding, surfacing welding, and thermal sintering. [0003] In the existing technology, the stainless steel seawater filter element is mainly manual arc welding at present, but due to the large number of solder joints and small connection points between the filter screen and the inner frame, defects such as unwelded or incomplete penetration, erosion, and weld penetration are prone to occur. The welding efficiency is particularly low, and a large amo...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problems of weak welding, corrosion, and low welding efficiency in welding stainless steel seawater filter elements by manual arc welding in the prior art, the present invention provides a composite welding method for stainless steel seawater filter elements. The base metal hardly melts, which can not only improve the connection strength and mechanical properties of the joint, but also lower the temperature during welding, which can effectively prevent the generation of nitrides, carbides, and carbonitrides at the joint to reduce its performance and avoid the problem of changes in structure and performance. The welded joint has no defects, high cleanliness and excellent performance