FRICTION STIR WELDING (FSW) OF A HARDENABLE ALLOY STEEL IN 'DRY' AND 'WET' ENVIRONMENTS

摘要

Recent advances in FSW tool material and design will facilitate numerous applications of this solid-state joining technology to steels. A single W-Re-CBN tool was used to conduct a series of bead-on-plate FSW traverses, approximately 1.5m in total length, on 6.3mm thick plates of a hardenable alloy steel. The first series of traverses involved various RPM/IPM combinations and a dry plate. A second series was carried out while a plate was immersed in water in order to assess potential for inducing hydrogen assisted cracking (HAC) during FSW of susceptible alloys. All traverses were defect-free. The FSW nuggets exhibited refined microstructures and increased hardness relative to the base plate. The influence of FSW parameters on nugget microstructure and mechanical properties will be summarized.