Surface quality of billets shall be free from all harmful defects like surface cracks, seams, laps, folds,scabs blowholes,deep ripple marks, aluminum patches, slag patches etc.

• 钢坯表面要避免一些瑕疵譬如裂纹，接缝，重叠，折痕，抓痕，深的波纹，斑点等。