| Title |
The Hot Enbrittlement Mechanism of KS SPS 5 Spring Steel |
| Authors |
최병학(B . H . Choe); 이후철(H . C . Lee) |
| Abstract |
The hot embrittlement of KS SPS 5 spring steel in austenite region was studied in order to clarify the cause and mechanism of surface cracking during preheating, hot forming and cooling operations in spring making with rolled steel. The loss of hot ductility was attributed to precipitation of nitrides which were identified as AIN by TEM. Sulfur did not influence the hot embrittlement in this steel because of its decreased solubility due to high Mn content. Through the TEM observation of the size and distribution of the precipitated particles the mechanism of hot embrittlement in spring steel was thought to be relative weakening of the grain boundaries caused by the matrix which is strengthened by AIN precipitates. The effects of the strain rate and the grain size on the hot ductility were discussed. |