SAE8640合金钢280mm×325mm连铸坯的高温力学性能

摘要

采用Gleeble 1500热模拟试验机对SAE8640钢280 mm× 325 mm连铸坯(/％:0.41C,0.20Si,0.80Mn,0.005S,0.014P,0.46Cr,0.43Ni,0.21Mo,0.043Alt,0.001 1O,0.005 4N)的550～1 200℃力学性能进行了测定,并应用扫描电镜观察了拉力试样的断口形貌.结果表明,SAE8640钢有明显的3个脆性区:Ⅰ脆性区＞1 200℃,Ⅱ脆性区950～1000℃,Ⅲ脆性区650～750℃;该钢950～1000℃的断面收缩率为60％,拉伸断口为脆性河流状花样,应避免在该温度范围进行轧制,该钢650～750℃的断面收缩率≥65％,拉伸断口为韧性断裂,可满足连铸坯矫直时塑性的要求.