As the interface follows the solidification front of the shell metal, the areas of soft core metal showing at the barrelsurface, will be patchy and not continuous.
由于结合层往往是沿着外层金属的凝固线所形成的，因此在辊身表面所呈现的此类缺陷是不连续，不规则的。
2
In the next phase, a fatigue, cat's tongue like fracture band propagates progressively in a circumferential direction running more or less parallel to the barrelsurface.
在下一个阶段，疲劳会逐渐向圆周方向漫延，呈现出平行于辊身表面的猫舌状断裂带。
3
One effective way is preferred pump barrel and plunger of materials and surface treatment processes.