Small atlas of residual stresses trajectories during surfacing or how to make steel ‘transparent’

Abstract

ABSTRACT The article shows the unique capabilities of the physical non-destructive magnetoelastic method by the example of creating a small atlas of the principal stresses trajectories fields (isostat) during electric arc deposition. The object of the research is two plates from steel St3 with dimensions of 500x400x8 and 400x200x8 mm, attached along the edges. Six deposition variants are carried out on their surface using a semiautomatic device in a carbon dioxide environment: ‘Parallel rolls’, ‘Circles’, ‘Fork’, ‘Arcs’, ‘Cross’, ‘Angle’, imitating common weld seams. The work presents the sequence of the isostat detection process: drawing a coordinate net on a sample, determining the inclination angles values of tangents related to the trajectories of the greatest principal stresses in the net knots, graphic constructions. The magnetoelastic method is implemented through the use mechanical stress metre – MSM-4 M with a sensor base of 5 mm, an operating frequency of 1000 Hz, an inclinometer error of ±2 degrees. An atlas of typical isostat fields is created on the basis of control at 1900 net knots on the surface of a compact steel sample. Visualization of power flows is provided, which makes the steel appear to be ‘transparent’ and opens up additional opportunities for researchers and production engineers to optimize deposition and welding technologies, and to evaluate the effectiveness of reducing residual stresses in various ways.