Tempering and Fracture Behavior of High Carbon Martensite.
Abstract
The effects of austenitizing and tempering on the fracture behavior and toughness of high carbon steels were investigated on martensitic specimens of AISI 52100 steel. Two levels of phosphorus content, 0.023 and 0.009 P, were evaluated. Specimens austenitized below Acm fractured primarily in a transgranular mode and showed slightly improved toughness, compared to the as-quenched condition, after tempering at 200 C. Higher temperature tempering resulted in reduced toughness before a substantial increase in toughness developed after tempering at 400 C and above. The effect of P was most pronounced in specimens tempered above 400 C, with the higher P specimens showing significantly lower toughness. Specimens austenitized above Acm failed primarily in an intergranular mode even in the as-quenched and low temperature-tempered specimens. Auger electron spectroscopy showed that the intergranular fracture was associated with thin carbide films that had apparently formed during quenching. Proeutectoid cementite grain-boundry allotriomorphy formation was stimulated by high P content. The prior austenite grain boundary carbide formation may not only cause the low toughness fracture at quenched and tempered specimens but may also be associated with the quench cracking frequently observed in high carbon steels. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1980
- Accession Number
- ADA092654
Entities
People
- George Krauss
Organizations
- Colorado School of Mines