Scale-bridging contrasting and characterization of multi-wire submerged arc welds and electron beam welds in steels

Abstract

Abstract For a comprehensive microstructural characterization of welds, a scale-bridging analysis of the microstructure is required. It is the only way to identify all microstructural characteristics relevant for the mechanical properties which, in turn, may cover several observation scales. The analytical methods used range from etchings for the macroscopic evaluation of the weld and heat-affected zone to the detection of so-called “local brittle zones” (LBZs) in the micrometre range. This paper will study weld joints in low-alloy steels produced by multi-wire submerged arc welding and electron beam welding. Macro and micro etching as well as electropolishing will be used for microstructural contrasting. Scanning electron microscopy will be performed to identify the finely dispersed carbon-rich secondary phase. Electron backscatter diffraction will enable the identification of so-called martensite/austenite regions (MAs) capable of acting as LBZs.