DEEP CRYOGENIC TREATMENT TO INCREASE THE WEAR LIFE OF MINING COMPONENTS

Cone crusher mantles, liners and ground engagement tools such as shovel or bucket teeth are short life items used extensively in mining and road construction. Increasing the ability for material work hardening and reducing the residual stress via Deep Cryogenic Treatment increases work life and reduces fatigue cracking caused by abrasive wear. Added work life translates to lower operating cost, increased equipment uptime and reduced risk of injury to mining personnel. Improved work life also lowers environmental impact by extending the initial carbon investment in cast mining items - primarily made from manganese (Mn) steel and high chrome white iron (HCWI).

Metallurgically, DCT triggers a reduction in stacking fault energy, increased twinning of grains (TWIP), increased dislocation density and increased yield strength in Mn steel and HCWI. This a-thermal transformation provides a vastly different explanation for wear life improvement then found in DCT of tool, die or carbon steel (phase change, austenite to martensite transformation, precipitation of wear-resistant carbides). That these mechanical property improvements occur without a simultaneous increase in hardness deepens the deep cryogenic phenomenon mystery - resulting in the need for new non-destructive test and validation tools to authenticate and certify DCT on mining grade cast steels.