Magnetic particle inspection method for small-size pipe socket fillet weld of boiler header

Abstract

The invention discloses a magnetic particle inspection method for a small-size pipe socket fillet weld of a boiler header. The inspection is completed by virtue of an open coil. The inspection method comprises the following steps that firstly magnetic particles are applied around the fillet weld between a pipe socket and the boiler header; then the longitudinal defect of the fillet weld is inspected by adopting a coil magnetization method; the transverse defect of the fillet weld is inspected by adopting an end contact method; and the coil magnetization method and the end contact method form bidirectional perpendicular magnetization and are respectively a unidirectional magnetization method. By adopting the open coil to complete the magnetic particle inspection of the pipe socket fillet weld and by adopting the coil magnetization method and the end contact method to form bidirectional perpendicular polarization according to the characteristic of the fillet weld, the defect of the fillet weld can be better and comprehensively inspected.

Description

technical field [0001] The invention relates to a detection method for small-sized pipe seat fillet weld defects, in particular to a magnetic particle detection method for small-size pipe seat fillet weld defects of a boiler header. Background technique [0002] As an important structural form, the corner connection form of the connecting pipe on the equipment is widely used in special equipment such as boilers, pressure vessels, and pressure pipelines. Due to structural reasons, the stress concentration of fillet welds is serious compared with butt welds, and cracks are prone to occur, resulting in unplanned equipment outages. Therefore, large batches of magnetic particle inspections are usually performed on fillet welds during equipment maintenance. However, the fillet weld has a special structure. Even for small-sized pipe seat fillet welds, magnetization using the commonly used yoke method requires multi-directional and multiple magnetization to complete all inspections....

AI Technical Summary

Problems solved by technology

However, the fillet weld has a special structure. Even for small-sized pipe seat fillet welds, magnetization using the commonly used yoke method requires multi-directional and multiple magnetization to complete all inspections.

Especially in the magnetic particle inspection of the fillet weld of the boiler header pipe seat, on the one hand, the number of pipe seats is large, and the magnetization efficiency of the yoke method is low;

Images