Vol.29 Suppl.1 林建农等：铌、钒、钛微合金化钢的边角部裂纹与高温延塑性 121· 塑性较差，只有含Ti,A、E钢温度≤800C,但E 性 钢随温度降低，RA值又下降到36%.当RA值> (4)二冷区喷嘴采用加幅切的方法，浇注窄断 40%,A、E钢温度脆性温度>830C:当RA值都> 面的铸坯时关闭幅切，以提高边角部热塑性温度， 40%,脆性温度须>950℃，若RA值>50%、60%， (⑤)提高拉速以提高铸坯表面温度. 热脆性温度会更高，二冷工艺参数即使采用较弱冷 (6)增大变形速率提高热塑性). 的二冷方式6（比水量0.45Lkg)也不能达到950C 以上. 参考文献 实际生产过程中，根据生产计划，通过调整板 坯厚度规格和冷却方式，在200mm厚度规格上实 [1]Mintz B,Yue S,June J.Hot ductility of steels and its relationship 现了无缺陷连铸坯热送。但在250,300mm厚度规 to the problem of transverse cracking during continuous casting. Int Mater Rev,1991,36:187 格上还需进一步改进。对于250,300mm厚度规 [2】王新华，王文军，费惠春，等.减少铌、钒、钛微合金化钢连 格的铸坯，采取加热轧制前连铸坯边角部全部清理， 铸坯角部横裂纹的研究.钢铁，1998,33(1)少：22 连铸坯计划外率大幅度降低 [3)马富吕.钢中铝钛含量对连铸坯轧制厚板表面质量的影响.钢 可以采取以下措施提高矫直区铸坯边角部温度 铁，1998,33(2：21 和热塑性， [4]王新华，张立，等.含Nb、V、Ti钢连转坯中碳、氮化物的析 (1)根据不同钢种的特性，制定出不同的二冷 出及钢的高温塑性.钢铁，1998,10(6：32 方式. [5]肖英龙.控制ā相析出改善连铸坯的高温塑性.量钢技术，2005 48(1):23 (2)试图寻找一种新的冷却模式，如先强冷后 [6]肖英龙.提高铸坯高温塑性抑制铸坯横向裂纹.宽厚板，11(2) 缓冷，控制铸坯表面显微组织减少铸坯边角部横向 42 裂纹的敏感性5-6. 7】王春怀，何宇明，等，含铌、钛船板钢高温塑性研究，铜铁 (3)采用在矫直前安装烧嘴以提高矫直区铸坯 2002,37(8):49 表面边角部温度，改善矫直区铸坯表面边角部热塑 Cracks of the side cape and the ductile plastic property in the tiny metal alloy of Nb,Ti,V LIN Jiannong,MA Fuchang,ZHAO Xiangzheng Steelmaking Plant of Wuyang Iron and Steel Co.Ltd.,Wuyang 462500,China ABSTRACT According to the test of the high temperature ductile plastic property and the surface temperature of continuous casting billets,when it contains Nb,V,Ti among 700-900C in the third brittleness temperature province,contraction of cross sectional area,the rate RA value is lower,about 36%.If the RA value is more than 40%,the ductile plastic property temperature is about 950C.Even adopting weak colding,the temperature of casting billet side cape also can't attain enough.Through the measurement,it can give the very big help towards drawing up the craft measure,improving the thermal plasticity of straightening areas and reducing cracks of the casting billet side cape.Combining with the production process and the actual conditions of the continuous caster in our plant,practical discussion and proposals have been made for the preventative measures of eliminating sur- face cracking. KEY WORDS steel containing Nb,V,Ti;continuous casting billet;high temperature ductile plastic property; cracks of steel side capeVol.29 Suppl.1 林建农等：铌、钒、钛微合金化钢的边角部裂纹与高温延塑性 • 121 • 塑性较差，只有含 Ti，A、E 钢温度 ≤ 800°C，但 E 钢随温度降低，RA 值又下降到 36%．当 RA 值 > 40%, A、E 钢温度脆性温度 > 830°C；当 RA 值都 > 40%, 脆性温度须 > 950°C，若 RA 值 > 50%、60%, 热脆性温度会更高，二冷工艺参数即使采用较弱冷 的二冷方式 6（比水量 0.45 L/kg）也不能达到 950°C 以上． 实际生产过程中，根据生产计划，通过调整板 坯厚度规格和冷却方式，在 200 mm 厚度规格上实 现了无缺陷连铸坯热送。但在 250，300 mm 厚度规 格上还需进一步改进。对于 250，300 mm 厚度规 格的铸坯，采取加热轧制前连铸坯边角部全部清理， 连铸坯计划外率大幅度降低． 可以采取以下措施提高矫直区铸坯边角部温度 和热塑性． (1) 根据不同钢种的特性，制定出不同的二冷 方式． (2) 试图寻找一种新的冷却模式，如先强冷后 缓冷，控制铸坯表面显微组织减少铸坯边角部横向 裂纹的敏感性[5−6]． (3) 采用在矫直前安装烧嘴以提高矫直区铸坯 表面边角部温度，改善矫直区铸坯表面边角部热塑 性． (4) 二冷区喷嘴采用加幅切的方法，浇注窄断 面的铸坯时关闭幅切，以提高边角部热塑性温度． (5) 提高拉速以提高铸坯表面温度． (6) 增大变形速率提高热塑性[7]． 参 考 文 献 [1] Mintz B, Yue S, June J. Hot ductility of steels and its relationship to the problem of transverse cracking during continuous casting. Int Mater Rev, 1991, 36: 187 [2] 王新华，王文军，费惠春，等．减少铌、钒、钛微合金化钢连 铸坯角部横裂纹的研究．钢铁，1998, 33(1): 22 [3] 马富昌．钢中铝钛含量对连铸坯轧制厚板表面质量的影响．钢 铁，1998, 33(2): 21 [4] 王新华，张立, 等．含 Nb、V、Ti 钢连铸坯中碳、氮化物的析 出及钢的高温塑性. 钢铁，1998, 10(6): 32 [5] 肖英龙．控制 а 相析出改善连铸坯的高温塑性. 重钢技术，2005, 48(1): 23 [6] 肖英龙．提高铸坯高温塑性抑制铸坯横向裂纹. 宽厚板，11(2): 42 [7] 王春怀，何宇明, 等，含铌、钛船板钢高温塑性研究，钢铁， 2002, 37(8): 49 Cracks of the side cape and the ductile plastic property in the tiny metal alloy of Nb, Ti, V LIN Jiannong, MA Fuchang, ZHAO Xiangzheng Steelmaking Plant of Wuyang Iron and Steel Co. Ltd., Wuyang 462500, China ABSTRACT According to the test of the high temperature ductile plastic property and the surface temperature of continuous casting billets, when it contains Nb, V, Ti among 700-900°C in the third brittleness temperature province, contraction of cross sectional area, the rate RA value is lower, about 36%. If the RA value is more than 40%, the ductile plastic property temperature is about 950°C. Even adopting weak colding, the temperature of casting billet side cape also can’t attain enough. Through the measurement, it can give the very big help towards drawing up the craft measure, improving the thermal plasticity of straightening areas and reducing cracks of the casting billet side cape. Combining with the production process and the actual conditions of the continuous caster in our plant, practical discussion and proposals have been made for the preventative measures of eliminating sur￾face cracking. KEY WORDS steel containing Nb, V, Ti; continuous casting billet; high temperature ductile plastic property; cracks of steel side cape