INTERMEDIATE TRANSFORMATION STRUCTURE AND CONTROL COOLING PROCESS IN LOW CARBON BAINITIC STEEL

摘要

The influence of processing parameters on the intermediate phase transformation for the low carbon microalloying steel was studied. Three kinds of microstructures were observed in the isothermally held specimens: the quasi-polygonal ferrite, intergranularly and/or intragranularly nucleated acicular ferrite and lath-like bainitic ferrite sheaves. During the continuous cooling, the cooling rate and the accelerated cooling start and finish temperature were investigated and the optimum TMCP process was determined for the low carbon bainitic steel.