摘要
角横裂是包晶钢连铸工艺中最为突出的质量问题,针对包晶钢角横裂的产生机理与控制技术进行了文献综述。w(C)=0.08%~0.18%的包晶和亚包晶钢由于在钢液凝固过程中存在δ相到γ相的转变,产生较大的线收缩,同时生成γ相的温度较高,原奥氏体晶粒容易长大,因此对裂纹非常敏感。对于含Nb、Al、V的包晶和亚包晶钢,在原奥氏体晶界的先共析铁素体薄膜中,容易析出Nb、Al、V的碳氮化物等第二相粒子,进一步降低了钢的高温塑性,从而容易产生角横裂。当先共析铁素体膜厚度超过5μm,钢的断面收缩率降低,钢的塑性下降,容易导致裂纹发生。包晶钢连铸坯角横裂的控制技术包括针对钢液成分、结晶器振动、二冷制度、倒角结晶器、保护渣性能的优化,以及保持良好的铸机设备状态。
Transverse corner crack is the most prominent quality problem in the continuous casting process of peritectic steel. In this paper, the mechanism and control technology of corner transverse crack in peritectic steel were reviewed. The peritectic and hypoperitectic steels with carbon mass fraction ranging from 0.08 % to 0.18 % are very sensitive to cracks because of the transformation from δ phase to γ phase during the solidification process of molten steel. At the same time, the temperature for the formation of γ phase is higher, and the original austenite grains are easy to grow, so they are very sensitive to cracks. For peritectic and hypoperitectic steels containing Nb, Al and V, the second phase particles such as Nb, Al and V are easy to precipitate in the proeutectoid ferrite film of the original austenite grain boundary, which further reduces the high temperature plasticity of the steel, resulting in the occurrence of transverse corner cracks.When the thickness of proeutectoid ferrite film is more than 5 μm, the reduction of area and the plasticity of steel decrease, which is easy to cause cracks.The control technology of corner transverse crack in continuous casting slab of peritectic steel includes optimization of liquid steel compositions, mold vibration, secondary cooling conditions, chamfering mold, mold powder performance, and maintaining good equipment status of continuous caster.
作者
蔡文菁
杨健
邓丽琴
左康林
吴旭峰
CAI Wenjing;YANG Jian;DENG Liqin;ZUO Kanglin;WU Xufeng(State Key Laboratory of Advanced Special Steel,School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;Shanghai Meishan Iron and Steel Co.,Ltd.,Nanjing 210039,China)
出处
《炼钢》
CAS
北大核心
2021年第2期37-46,57,共11页
Steelmaking
基金
国家自然科学基金钢铁联合研究基金重点支持项目(U1960202)。
关键词
包晶钢
连铸
角横裂
机理
控制
peritectic steel
continuous casting
corner transverse crack
mechanism
control