INFLUENCE OF RARE EARTH ON TTT DIAGRAM FOR 0.27C-1Cr STEEL
稀土对0.27C—1Cr钢TTT图的影响

TTT diagrams of the 0.27C-1Cr and 0.27C-1Cr-RE steels are established by means of dilatometric measurement for kinetic curves at different temperatures and metallographic inspections, and the influence of RE on the TTT diagram is studied. The addi- tion of RE refines austenite grains, retards grain growth rate, raises Ac_3 and makes no change to Ac_1. The incubation periods for proeutectoid ferrite and bainite are reduced, and the time for complete transformation for pearlite and bainite are prolonged by the addition of RE. The computation result are in comformity with the experimental ones.