Experimental Research on Improving Weldability of Steel by Precipitates of Silica During Rapid Cooling

A new idea that the grain can be refined by lots of fine and disperse silica particles precipitated during rapid cooling is presented in this paper based on the progress trend in oxides metallurgy. According to this idea, experiments have been made and its conclusions are as follows. During rapid cooling, silica particles cannot precipitated in the grain boundary, and its diameter is 2 μm or so, which is too big to pin in the grain boundary at high temperature, and it is rather diffcult for these silica particles to act as nuclei of phase transition to induce ferrite.