Microstructure, Mechanical Properties and Two-Body Abrasive Wear Resistance of an Fe-3Cr-C Based Ultra-High Strength Steel

摘要

An ultra-high strength steel based on Fe-3Cr-0.4C for structural and abrasive applications has been designed and its structure-property relationships have been established. The microstructure has been characterized as dislocated lath martensite containing fine carbides and surrounded by thin films of retained austenite. This results in excellent combination of mechanical properties and abrasion resistance which are attractive in comparison to many commercial abrasion-resistant alloys. It has been shown also that the abrasion resistance mainly depends on the hardness. Tempered martensite embrittlement occurs in the tempering temperature range of 300 to 400 exp 0 C and has been confirmed to be coincident with the decomposition of interlath retained austenite into stringers of coarse cementite. EPSILON-carbide has been found in the as-quenched condition and in the 200 exp 0 C tempered condition. The most likely sites for the formation of the cementite are shown to be the epsilon-carbide interfaces with the matrix and as the cementite particles grow, the epsilon-carbide particles gradually disappear. (ERA citation 09:035802)