Investigation of the structure, microhardness and distribution of chemical elements in the boundarylayer of a bimetallic joint made of steel and brass, obtained by explosion welding

The paper presents the results of investigation of the microstructure, microhardness and distribution of chemical elements in the boundary layer of welded joints obtained by explosion welding between the plates of steel St 3 and brass L 63 in a bimetallic plain bearing of the "sleeve" type. Analysis of the boundary (transition) layer of the compound revealed a single defect - an "air bubble", presumably formed by gas products released during the chemical reaction of elements, an explosive. No other significant defects were found in the transition layer of the joint. The junction border has a wavy structure, where the average wave length and amplitude are 1,065×103 and 173 μm, respectively. The thickness of the boundary (transitional) layer varies from 1.3 to 43.7 μm, while the average value is 15.5 μm. In this transition layer, there is an interpenetration of steel and brass, which provides a particularly strong connection with combined values of microhardness.