Analysis of the Mixing of Filler and Base Materials in Arc-Welded Single-Bead Surface Welds Using an EDXS Method.

Borut Zorc,Matija Zorc,Aleš Nagode

doi:10.3390/ma15010217

Borut Zorc, Matija Zorc + Show 1 more

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https://doi.org/10.3390/ma15010217

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Abstract

This article deals with an analysis of mixing and determines the admixing rate of a base S355 steel plate in single-bead surface welds by measuring the chemical composition using a plane-scan energy dispersive X-ray spectroscopy (EDXS) on metallographic cross-sections. The results show that obtaining a larger number of EDXS measurements does not necessarily lead to obtaining a more accurate admixing rate. Due to the ever-present segregations that are generally near the base material, the disadvantage of this method is the subjective influence of the SEM operator on the estimated admixing rate. To obtain relevant results, a sufficiently wide area of well-mixed melt, including segregations, must be analyzed. This study showed that by using a sufficiently large number of appropriately selected sites with a sufficiently large surface area, it is possible to estimate the admixing rate from the chemical composition with an accuracy of ≥96% for the geometrically determined admixing rate D = 30%. From several equations, the best result showed an equation which is the arithmetic mean of the two different arithmetic means and in which the artificial influencing factor of the segregations of the base material is taken into account. With this equation, the same value of admixing rate, D = 30%, was obtained using the comparative geometric method.

Highlights

During fusion welding, a molten part of the base material is admixed with the melt of the filler material, where the admixing rate of the baes material is about 10–40% [1,2,3] for arc welding with a coated electrode and as much as 70% for submerged arc welding [2]
The best result showed an equation which is the arithmetic mean of the two different arithmetic means and in which the artificial influencing factor of the segregations of the base material is taken into account
The chemical compositions of the base S355 steel, the filler materials, and the singlebead surface welds as well as the calculated admixing rates of S355 steel in the individual surface welds are given in Table 1, which includes the values from [1]

Summary

Introduction

A molten part of the base material is admixed with the melt of the filler material, where the admixing rate of the baes material is about 10–40% [1,2,3] for arc welding with a coated electrode and as much as 70% for submerged arc welding [2]. Several methods for determining the admixing rate of the base material in single-bead surface welds are known These include using the mass of the melted base and filler materials [5], using the ratio of the area of the metallographic cross-section [1,4,6,7,8,9,10,11], using the ratio of the heights of the metallographic cross-section [1], using the volume fraction of the melted base and filler materials [7,8], using the chemical composition measured by an electron-probe micro-analyzer [1,8], and using the welding parameters and the material thermal-physical quantities [1,7,8]. The influence of the admixing rate on the metallurgical and mechanical properties of multi-weld welds has been investigated [12,13,14]

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