PREPARATION OF HOT ROLLED CARBON ROD FOR COLD WORKING.

Experiments are described which indicate that for a brief period of about 15 to 35 seconds following hot rolling of medium to high carbon steel rod, a progressive reduction in the austenite grain boundary area takes place depending on the laying temperature and the cooling rate following hot rolling. In addition, this grain boundary area reduction continues relatively rapidly even at temperatures approaching A//3. Provided substantially the same average cooling rates both above and through transformation at a given cross-section are maintained, a compensating effect takes place which ensures uniformity of mechanical properties in the end product despite non-uniform cooling rates along the rod.