末端压下工艺改善车轴钢大圆坯中心缩孔的研究

Study on improvement of center shrinkage cavity in axle steel round bloom by end reduction process

研究了LZ50车轴钢Ф690 mm大圆坯末端压下位置对改善中心缩孔的影响,提出了压下过程表面横裂纹的控制措施,达到了显著减轻中心缩孔的效果。研究表明:大圆坯末端压下可以将变形有效传递至铸坯心部,从中心固相率0.20开始实施压下能起到减轻缩孔的效果,可将铸坯的最大缩孔尺寸由10 mm减小至3 mm以下。末端压下时应控制铸坯表面温度在800℃以上,才能避免铸坯表面出现横向裂纹。

The influence of end reduction position of Ф690 mm round bloom of LZ50 axle steel on improving the central shrinkage cavity was studied, the control measures of surface transverse crack in the reduction process were put forward, and the central shrinkage cavity was significantly reduced. The results showed that the deformation could be effectively transferred to the center of the bloom by the end reduction. The effect of reducing shrinkage cavities could be achieved by rolling down from the central solid fraction of 0.20,and the maximum shrinkage cavity size of the bloom could be reduced from 10 mm to less than 3 mm. When the end is pressed, the bloom surface temperature should be controlled above 800 ℃ to avoid transverse cracks on the surface of the bloom.