Effect of molybdenum and temperature reduction on hot ductility of 0•2C-Mn steels

The influence of up to 0.4%Mo and temperature reduction before strain on the hot ductility of 0.2C-Mn-Al steels was investigated using a Gleeble 1500 thermal simulator. With the addition of 0.4%Mo, the ductility was reduced in the austenite temperature region because the precipitation of carbides was encouraged. However, ductility improved in the ferrite-austenite dual phase region because a solution of Mo in the ferrite reduces the difference between the strength of ferrite and austenite and results in a more homogeneous distribution of strain between the boundaries and the matrix, A temperature reduction introduced before straining seriously impaired ductility, especially when it resulted in phase transformation, owing to the enhanced precipitation of carbides.