Study on influence of controlled-cooling on properties of ultra-low carbon bainitic steels

The study on ultra-low carbon Bainite steels discovers that during controlled -rolling processing of strip steels, the cooling type, cooling rate after finished rolling and coiling temperature ( CT degrees C) are the most important factors, which directly control the type of bainitic ferrite (dislocation substructure form alpha B. shelf-like structure alpha degrees B) and each containing fraction; the width of lath structure; dislocation density; the number. size and distribution of M-A island and precipitations (include epsilon -Cu), therefore, it has direct effects on the elongation and yield strength of steels. This study is aimed to find the feature of ultra-low carbon bainite microstructure and its relationship with controlled - cooling and properties of steels.