Discussion about the mechanical properties relationship between the natural cooling and 200 ℃ water cooling HRB400E

The steel samples taken to the laboratory after the completion of the rolling process should be cooled in the air for 3 to 5 hours before test，and the inspection cycle can be shortened to improve the test speed. The HRB400E air cooling sample，200 ℃ water cooling sample and 200 ℃ sample were compared. Taken the air cooling sample as reference standard，the test samples of the other two kinds were carried out by mechanical properties testing and metallographic analysis. Experiments showed that the mechanical properties and metallographic structure of 200 ℃ water cooling and the air cooling specimens had no obvious differences and could be substituted for each other. Therefore，after the rolling，the hot steel samples sent to the mechanical properties laboratory were put into the water to be cooled and tested，which can shorten the inspection time for two to four hours.