Investigation on the effect of cryogenic treatment on tungsten carbide milling insert with 11% cobalt (WC-11%Co)

The objective of this research is to evaluate the performance of cryogenically treated cemented carbide milling inserts with 11% cobalt content in face milling of EN19 steel. Two different deep cryogenic treatments at temperature of around - 193 degrees C were performed on the inserts, namely cryogenic treatment and cryogenic treatment and tempering. Uncoated tungsten carbide face milling inserts with 11% cobalt content were used in this research. Machining tests were conducted at the catalog recommended cutting parameters, and flank wear and nose wear of untreated, cryogenically treated and cryogenically treated and tempered inserts were compared to study the performance. The experimental investigation revealed that both cryogenic treated and cryogenic treated and tempered inserts showed 4-7% lesser flank and nose wear than the untreated inserts. The metallurgical examinations using indirect measurement technique revealed the phase transformation of cobalt from FCC to HCP which could have resulted in increased hardness, reduced friction coefficient and improved tool life.