The study of volumetric wearing of PCBN/W-Re composite tool during friction stir processing of pipeline steels (X70) plates

Friction stir welding is a solid-state joining/processing technique that offers high strength and productivity, resulting in microstructure similar to hot working cycles. However, melting temperature metals such as steels cause excessive wear over tools, representing significant economic issue. Most studies conducted have used polycrystalline cubic boron nitride (PCBN) W-Re composite which offer combination of hardness at temperatures, along with high-temperature stability. even those tools are susceptible tool wear. In the present study, experimental data was collected during friction processing X70 grade pipeline steel plates, using PCBN under well-controlled conditions. Profilometry optical microscopy were quantify volume loss due number plunges welded distance. Torque transverse force bead width measured related process. Tool contamination boron-nitrogen particles dissolved tungsten identified hard zones, more substantial latter.