Influence of carbon and chromium content and preform shape on the microstructure of spray formed steel deposits

Given appropriate control of spray- and substrate-movement spray forming can be used to produce a variety of preforms. The microstructure obtained is governed by the thermal conditions during the spray forming process which can be influenced by the material properties, the atomization and deposition conditions. Within this study, the influence of carbon and chromium content as well as the preform shape on the microstructure is investigated. As master material unalloyed steels with low and high carbon content (SAE 1015, SAE W110 and SAE 52100) have been selected. Billets, plates and parts with defined geometry have been spray formed using different atomization gas pressures and comparatively examined by quantitative metallography and density measurement. It is found that the carbon content and the atomization gas pressure strongly influence the development of porosity. Also the state of the mould surface plays an important role. In contrast, the variation of preform shape and chromium content reveals no significant change.