Considerations about tempered martensite embrittlement

There have been many quite meritorious studies made about the present subje ct. However, there are still some open questions: whether the mechanism of plastic deformation is the same in the Charpy test and in the slow static t est, and what is the effect of the rate of work-hardening. The material sel ected for the tests was a common Cr-Mo steel. The long time tempering was c arried out in a salt bath. A welding simulator was applied for the very sho rt tempering. The stress-strain curves at some interesting tempering temper atures were determined by torsion tests. The Charpy impact tests were accom plished using V and U shaped specimens. The deformation and fracture of the specimen were studied with optical and scanning electron microscopes. Ther e was no tempered martensite embrittlement in the specimens in the very sho rt tempering time. (C) 1999 Elsevier Science S.A. All rights reserved.