板材剪切横裂原因

板材剪切横裂纹源于连铸坯相应部位的柱状晶晶间裂纹,而柱状晶晶间裂纹是由于矩形连铸坯宽面柱状晶区的收缩应力向两侧传递,在靠近窄面柱状晶区末梢形成拉应力,进而造成柱状晶晶间裂纹。对于包晶钢应尽量避开碳含量的裂纹敏感区或采用轻压下技术可减少裂纹的出现,还应注意轧制剪切温度以避免轧制后晶间裂纹的焊合面再撕开造成剪切横裂

Analysis is on the Forming Causes of Shearing Transversal Grack in slab

The shearing transversal crack in slab is resulted from the intercystalline crack of continuous casting blank at relevant position. The intercrystalline crack of colunnar crystal is generated from the shrinkage stress of wide - face columnar crytal area in rectangular continuous casting blank delivers to two sides, which results in the forming of tension stress near the tip of nardow - face columnar cystal area. In order to reduce the appearance of crack in peritetic steel, the crack sensitive area of carbon content should be avoided or the technique of soft reduction should be adopted. In addition, in order to avoid the tearing again of weld faces among intercrystalline cracks, the orller milling and shearing temperature should be also paid affentionto.