To improve the straight edge seam defect on hot-rolled steel plates,the deformation and temperature distribution of rectangular slabs and chamfered slabs during rolling in a pilot rolling experiment were analyzed in d...To improve the straight edge seam defect on hot-rolled steel plates,the deformation and temperature distribution of rectangular slabs and chamfered slabs during rolling in a pilot rolling experiment were analyzed in detail using the finite element method.The results showed that the crease formed on the lateral side near the edge of the plate as a result of uneven stress during broadside rolling.The creases rose to the surface with unrestricted spread and evolved into a straight edge seam during the subsequent straight rolling.To eliminate the straight edge seam defect,chamfered slabs were developed and investigated for rolling.The use of the chamfered slabs provided two advantages for rolling：the distribution of the temperature near the edge was ameliorated,and the deformation shape was improved by the chamfered shape.As a result,the risk of forming a straight edge seam defect was reduced by the use of a chamfered slab.展开更多
基金Item Sponsored by National Natural Science Foundation of China(51204059)
文摘To improve the straight edge seam defect on hot-rolled steel plates,the deformation and temperature distribution of rectangular slabs and chamfered slabs during rolling in a pilot rolling experiment were analyzed in detail using the finite element method.The results showed that the crease formed on the lateral side near the edge of the plate as a result of uneven stress during broadside rolling.The creases rose to the surface with unrestricted spread and evolved into a straight edge seam during the subsequent straight rolling.To eliminate the straight edge seam defect,chamfered slabs were developed and investigated for rolling.The use of the chamfered slabs provided two advantages for rolling：the distribution of the temperature near the edge was ameliorated,and the deformation shape was improved by the chamfered shape.As a result,the risk of forming a straight edge seam defect was reduced by the use of a chamfered slab.
文摘针对现有满瓶检测算法中缺乏聚对苯二甲酸乙二酯(polyethylene terephthalate,PET)瓶防盗环断裂检测算法的问题,提出一种基于轮廓曲率计算和角点检测的防盗环断裂检测算法。首先采用灰度投影法大致定位出瓶盖区域并将瓶盖所在的矩形区域设置为感兴趣区域(ROI),再利用梯度极大值抑制法获取瓶盖边缘点,并根据提出的等腰三角形法和最近点搜索法,拟合边缘点的亚像素坐标并连接瓶盖轮廓。然后利用边缘点的路程距离比(stretch to distance ratio,SDR)来近似表示轮廓曲率,再根据轮廓曲率极大值检测角点,并采用角点匹配法定位支撑环。最后根据支撑环和防盗环之间存在缝隙与否,来判断防盗环是否断裂。该算法检测正确率达到94.75%,可满足生产需要。
