摘要
Mn13高锰钢连铸坯有纵向裂纹。采用扫描电镜、高温拉伸试验和高温激光共聚焦显微镜、电子探针分析等检测了裂纹的形貌、Mn13钢的高温力学性能以及Mn13钢凝固过程中的组织演变。试验结果表明:纵向裂纹深度达40 mm,裂纹附近无保护渣卷入;Mn13钢在1200℃以下温度的塑性较差,较易开裂。在1200℃左右Mn13钢奥氏体晶界开始析出碳化物,进一步增大了铸坯的开裂倾向;由于结晶器内保护渣熔化不均匀,导致凝固坯壳厚度不均匀,从而使铸坯产生凹陷和纵向裂纹。提高凝固坯壳厚度和结晶器热流的均匀性是避免Mn13钢连铸坯纵向开裂的重要途径。
Continuously cast slab of Mn13 high-manganese steel exhibited longitudinal cracks.Pattern of the crack,mechanical properties of Mn13 steel at high temperatures and microstructures during solidifying were tested by the aid of SEM,high temperature tensile test,confocal high-temperature laser microscope and electron probe analysis.The results showed that the longitudinal crack was as deep as 40 mm,and no involved mold powder was found near the cracks.The Mn13 steel showed poor plasticity at temperatures lower than 1200℃thereby was easy of cracking.Carbides precipitated in austenite grain boundary of the Mn13 steel at about 1200℃,thus further increasing cracking tendency of casting slab.The solidifying shell thickness was uneven duo to non-uniform melting of mold powder in the mold with the result that the slab formed gab and crack.The improvement in uniformity of both thickness of solidified shell and heat flow in mold is an important way to protect the continuous casting slab of Mn13 steel from longitudinal cracking.
作者
庄伟
ZHUANG Wei(Baowu Special Metallurgy Co., Ltd., Shanghai 200940, China)
出处
《上海金属》
CAS
北大核心
2020年第4期40-43,49,共5页
Shanghai Metals
关键词
高锰钢
连铸坯
纵向裂纹
high manganese steel
continuous casting slab
longitudinal crack
