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CSP薄板坯连铸钢水质量的控制及连铸蓄流分析一、CSP薄板坯连铸连轧的含义CSP:Compactstripprocess二、CSP薄板坯连铸连轧的产品结构1、马钢CSP产品结构：热轧、冷轧低碳钢：SPHC冷轧冲压级低碳钢：SPHD集装箱板：SPA-H一般结构钢：SS400电工钢：MG_W540,MG_W600汽车结构板2、ThyssenKrupp的CSP产品结构：序号钢种比例％1低碳钢62.52钛合金低碳钢7.43结构钢（0.06~0.085%C)5.64结构钢（0.16~0.22%C)0.45细晶粒结构钢7.66深冲钢07带钢38高碳钢(0.30～0.49％C)0.79硼合金钢0.110高碳钢(0.50～0.80％C)0.111电工钢12.312IF钢0.213复相组织钢0.13、美国第纳米克斯厂的CSP产品结构：4、AST钢厂的CSP产品结构：三、CSP薄板坯连铸连轧工艺中的关键技术1、结晶器与浸入式水口：漏斗式结晶器，其上口中间部位厚度达150mm，有利于浸入式水口的伸入和保护渣的熔化。目前采用的大十字出口状水口可增加钢水流量，稳定拉速，在高拉速下更能显示其优越性，且水口壁厚，寿命长大8～10小时。2、液芯压下技术：LCR（liquidcorereduction)是在铸坯出结晶器下口后，对坯壳施加挤压，液芯仍保留在其中，经二冷扇形段，液芯不断收缩直至薄板坯全部凝固。液芯压下实际上是在黏稠区（两相区）内加工，它将导致铸坯内部晶粒破碎和滑移，可得到较细的晶粒，使得铸坯在相同轧制温度下获得更好的韧性。÷液芯压下有以下优点：1.改善表面质量：结晶器厚度增大、弯月面稳定性好、润滑更好；2.改善内部质量：中心偏析和疏松减小、柱状晶破碎，晶粒细化；3.生产灵活性：铸机可按最合理方式进行生产。3、高压水除鳞技术：薄板坯出连铸机后，不像传统生产方法将板坯冷却后，再次加热进行轧制。而是出连铸机后马上进入加热炉加热保温，加热时间为15～20min，随后立即进入除鳞机除鳞，因此氧化铁皮很薄并且很黏，因此薄板坯生产热带的表面质量一直是比较大的质量问题。针对这一问题开发了新型除鳞工艺：冷却水喷嘴固定，水流以一定角度喷射到板坯表面，为防止水在板上残留，在除鳞机的水流反射面的上方安装有集水器，收集残留的水。同时提高水压到35～44MPa。四、CSP薄板坯连铸连轧工艺对钢水质量的要求1.洁净的钢水2.钢水成分的控制3.合适的钢水温度1.钢水成分控制典型钢种CSiMnPSAltAlsNCaSPHC0.0350.0310.0980.0120.00150.030.0290.00430.004SPHD0.0050.0520.20.0110.00120.0590.0560.00440.004①控制钢中C含量；②控制LF炉精炼过程中的增Si；③控制LF炉精炼过程中的增N；④尽量脱除钢中S含量；⑤控制钢中Als和Alin；⑥控制钢中Ca含量在适当的范围。10.07％Als,0.012%N2.0.026%As0.010%N3.0.014%Als0.011%N4.0.004%Als0.003%NNo.CSiMnPSAlsCa10.010.0280.210.010.0040.0150.000920.0080.0180.190.0110.0030.0330.002930.0120.0310.190.0160.0070.0330.0033No.CSiMnPSAlsCa10.0360.0210.180.0090.0030.0450.002120.0470.0330.220.0110.0020.0310.002730.0430.0360.180.0170.0010.0360.0033炉号样号S%Alt%Als%Ca%2-1059LF10.010.070.057LF40.0080.570.049LF50.00280.0320.030.0029LF60.00270.0330.029LF70.00210.0360.030.00232-1062LF10.00440.060.058LF40.00120.0380.0310.0038LF50.00140.0360.0260.0037LF60.00140.0360.0330.00323-983LF10.00880.0230.017LF40.00350.0330.0210.0078LF50.00240.0260.0240.00383-984LF10.00520.0570.057LF40.0030.0290.025LF50.00230.0230.0190.0043LF60.00220.0230.0210.0043-985LF10.00930.0470.039LF30.00190.0340.0220.0037LF40.00210.0320.0270.003LF50.00210.0340.0230.0036LF60.00180.0320.0290.0033-986LF10.0130.0460.035LF40.00920.0270.020.0036LF50.010.0260.0190.0037LF80.00950.0170.00880.00143-987LF10.01100.0380.029LF160.00350.0280.0250.00333-986LF最后一个试样Als仅为0.0088％、Ca仅为0.0014%，3-986炉浇注中期,水口蓄流,塞棒开口度上抬,3-987炉后期水口结瘤严重,停浇。炉号样号S%Alt%Als%Ca%3-1038LF10.0170.0130.0067LF20.0120.0270.025LF30.00620.0260.025LF40.00440.0260.0230.0032-1118LF10.0130.0460.044LF20.0120.0440.038LF30.00660.030.026LF40.00410.0260.0230.0033-1039LF10.0150.0240.015LF20.0120.0320.025LF30.00820.0240.02LF40.00740.0240.020.0016LF50.00710.0310.0280.00332-1119LF10.0110.0160.013LF20.00830.0320.023LF30.00680.0290.0240.0032LF40.00630.030.0270.00323-1040LF10.01200.0580.051LF50.00640.0290.0270.0020中包A0.00640.0220.0130.0011中包B0.00700.0220.0130.0010中包Ca含量降低较多，夹杂铝含量上升2.钢水温度控制15501570159016101630165016701690出钢YQYHLF加热前LF加热后喂线前喂线后3-98703-98713-98723-98733-98743-98753-9876CasterThroughputVLadleTemp11.522.533.544.51.52.02.53.03.54.04.55.05.56.06.57.0CastingSpeedCastTonnespermin02468101214DwellTimemins90x900mm70x900mm50x900mm90x1250mm70x1250mm50x1250mm90x1600mm70x1600mm50x1600mmDwellTime5.CSP蓄流情况分析1.大包烧氧导致水口蓄流2.中包盖耐材脱落导致水口蓄流3.LF精炼效果较差导致水口蓄流4.单开炉次中包吸氧导致水口蓄流5.水口壁受[Ca]侵蚀导致水口蓄流6.浇注过程中二次氧化导致水口蓄流炉号样号S%Alt%Als%Ca%3-903LF10.0130.0080.003LF20.0110.0270.021LF30.00990.0160.012LF40.00840.0350.0260.0043LF50.00830.0360.0240.00482-981LF10.0140.0140.0089LF20.0140.0270.015LF30.0130.0170.01LF40.00690.0380.034LF50.0050.0310.0290.0026LF60.00470.0330.030.00272-982LF10.0130.0210.016LF20.0120.0250.018LF30.00760.0270.023LF40.00520.0240.018LF50.00380.0290.0250.0041LF60.00390.0290.0280.00373-904LF10.01200.0290.021LF50.00620.0320.0290.00353-904大包烧氧三次，水口蓄流停浇。大包钢水称重曲线（红线）出现4个平台，表示烧氧4次，之前塞棒控制曲线（绿线）一直比较平稳，从烧氧开始，塞棒开口度曲线逐渐上升，同时液面控制曲线（蓝线）波动异常，烧氧过程中塞棒开口度不断提高、液面波动加剧，导致自动停浇。从中包、LF炉成分变化情况可以看出，大包烧氧导致钢水[O]含量急剧增加，Als含量急剧下降，钢中富积大量的Al2O3夹杂，导致水口结瘤严重。炉号样号C%Si%Mn%P%S%Alt%Als%Ca%[O]ppm[N]ppm2-1472LF10.060.0160.270.00910.00880.0280.024LF20.0620.020.280.00590.00570.0290.0290.002624.340.4中包A0.0590.020.270.00910.00670.0170.00880.001684.564.9中包B0.0590.020.270.00720.00570.020.0110.001779.564.9炉号SAltAlsCa脱S率3-1425LF10.00860.0670.064LF20.00850.0640.052LF30.00250.0420.0370.006467%中包10.0040.0280.0180.0023中包20.0040.0280.0190.00283-1427LF10.00750.0140.0083LF20.00740.0390.03LF30.00410.0420.031LF40.00280.0370.0250.005LF50.00430.0320.0250.003750%中包10.0040.0210.010.0012中包20.0040.0210.0080.00113-1427炉为3月15日生产连浇第二炉，开浇烧氧，中包只剩11t钢水时大包水口烧开，此时由于中包液位较低，拉速下降较多，为提拉速，塞棒开口度上抬，随后又进行第二次烧氧，钢水由于烧氧存在大量Al2O3夹杂，造成水口蓄流，两个因素共同作用，迅速造成塞棒开口度上抬到限位，铸机自动停浇。炉号样号SAltAlsCa脱S率3-1434LF10.00750.0380.016LF20.00570.0340.026LF30.00210.0340.0320.003172%3-1435LF10.00990.0150.01LF20.00840.0290.023LF30.00310.00310.0023LF40.00320.0310.025LF50.00360.020.0170.003764%3-1436LF10.0130.00790.004LF20.0120.00660.027LF30.00810.00190.0011LF40.00680.030.027LF50.00650.0230.020.0025LF60.00670.0240.0160.002950%此炉3月16日生产的，为连浇第三炉，烧氧开浇，断面1500mm3-1308中包盖耐材脱落造成水口蓄流LF精炼脱硫率较低，钢包渣氧化性较强，钢中活度[O]含量高，精炼之后钢包调运、浇注过程中，大包到中包的Als损较大，钢中Als与活度[O]反应生成大量高熔点的Al2O3，导致水口蓄流。炉号样号SAltAl