Microstructure and mechanical behavior of dissimilar AISI 304L/WC-Co cermet rotary friction welds

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 758; pp. 36 - 46
• Main Authors: Cheniti, Billel, Miroud, Djamel, Badji, Riad, Hvizdoš, Pavol, Fides, Martin, Csanádi, Tamás, Belkessa, Brahim, Tata, Malik
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05.06.2019; Elsevier BV
• Subjects: AISI 304L ASS; Austenitic stainless steels; Bonding strength; Cemented carbides; Cermets; Chromium; Cobalt; Dynamic recrystallization; Friction welding; Grain size; Heat affected zone; Intre-diffusion; Mechanical properties; Metallurgy; Microstructure; Modulus of elasticity; Nanoindentation; Rotary friction welding; Scratch tests; Tungsten carbide; WC-Co cermet; Welded joints; Bonding strength; Intre-diffusion; AISI 304L ASS; Microstructure; WC-Co cermet; Rotary friction welding
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2019.04.081

In this work, dissimilar rapid Rotary Friction Welding of WC-Co cermet to AISI 304 L austenitic stainless steel has been conducted using different friction times. The microstructural examination showed that the increase in friction time from 4s to 12s increases the grain size in both the heat affected zone and the thermo-mechanically affected zone and enlarges the extent of the fully dynamically recrystallized zone. EDS analysis revealed the existence of a FeCrW rich band along the WC-Co/AISI 304 L interface in the central region of the weld joint and its absence from the peripheral region. The formation of this band suggests the occurrence of a mutual inter-diffusion between the cermet and the steel which enhanced the metallurgical bonding of the interface. The mechanical behavior investigated by nano-indentation measurements and nano-scratch tests revealed that, regardless the friction time effect and considering the 304 L ASS side, the highest hardness (HIT) and the lowest Young's modulus (EIT) values were recorded in the fully dynamically recrystallized zone. Besides, the increase of friction time resulted in an increase of hardness and Young's modulus of each zone in the AISI 304 L steel side.