Processing and Ductile-Brittle Transitions in PM Manganese Steels

Brittleness in manganese steels can be associated with processing in a "wet¿ [micro]climate resulting in the formation of continuous oxide networks. The formation of these networks can be prevented by sintering in an atmosphere, also ¿local¿ in a semiclosed container, adhering to the Ellingham-Richardson oxide reduction criteria. When this requirement is satisfied, however, further types of ductile ¿ brittle transitions are observed. Rapid cooling, typically above 40°C/min, produces enough martensite to render Fe-(3-4)Mn-(0·6-0·7)C material macroscopically brittle. Quenched and conventionally tempered structures remain brittle. It is tentatively suggested that segregation of minor alloying/tramp element(s), as in cast materials, is responsible for this temper embrittlement. To overcome it, heat treatment at a temperature no higher than 200°C, recovery/stress relief, is recommended.

URI

http://hdl.handle.net/10454/892

Version

Accepted manuscript

Citation

Cias A and Mitchell SC (2005) Processing and Ductile-Brittle Transitions in PM Manganese Steels. Powder Metallurgy Progress. 5(2): 82-91.

Type

Article