1956 Volume 42 Issue 4 Pages 333-337
The material corresponding to a die steel No. 5 as spring material in high temperature was heat-treated in the constant hot bath which was considered as the best one being based on the former experiments. Then, impact hardness test in high tempetature, hardness test in room temperature, impact test, fatigue test by the Upton Lewis testing machine and microscopic test were carried out and also, impact hardness test of ordinary quench-tempered Si-Mn steel at high temperature was carried out.
These results were summarized as follows.
(1) On the material corresponding to a die steel No. 5, the treatment in 600°C constant hot bath quenched from 1100°C was ieconfirmed as the best heat-treatment.
(2) In the impact hardness test of ordinary quench-tempered Si-Mn steel, the almost linear descending inclination of impact hardness was recognized with ascent of testing temperature.