Effect of copper on edge cracking behavior and microstructure of rolled austenitic stainless steel plate

Cu is known to affect the edge cracking characteristics of austenitic stainless steel as it causes embrittlement. The hot rolling test of four kinds of austenitic stainless steel with different copper content (0, 2.42, 3.60 and 4.35 wt.%) was carried out to examine the effect of hot rolling cracks on steel containing different copper contents. The evolution of crack and microstructure was analyzed using the scanning electron microscope, energy-dispersive spectrometer, electron back scattered diffraction and transmission electron microscope. Experimental results showed an upward trend in edge cracking degree when Cu content was 4.35%, and the crack extended from the edge of the steel plate to the middle by about 14 mm. Besides, severe oxidation was observed inside the crack by fractography. With the increase in copper content at 1250 °C, the content of {110}<112> brass and {112}<111> copper textures decreased. When the content of copper was 4.35%, the decrease was most significant, and {112}<111> copper texture content decreased to only 0.5%. Generally, the textures of 2.42%Cu and 3.60%Cu 304L steel changed little, while a large change in the texture of 4.35%Cu 304L steel was observed. To conclude, the increase in rolling temperature can prevent edge crack and its propagation effectively.