初轧辊使用条件极端苛刻,辊身除受交变的弯曲正应力外,还受扭转切应力作用,轧辊表面由于与高温锭接触后立即脱离而进入水冷,从而形成热疲劳,使得轧辊深1mm的表面内形成网状的龟裂纹,这种裂纹虽然在轧辊运行一段时间后可以自行磨损消除,但在这段时间内网状的龟裂纹有的已形成为裂纹扩展的裂纹源,随着 In addition to being subjected to alternating bending positive stress, the roll is also subject to torsional shearing stress. The surface of the roll enters the water-cooled state as soon as it comes into contact with the hot-temperature ingot, forming a thermal fatigue so that the roll has a depth of 1 mm The surface of the network to form a turtle crack, although the cracks in the roll after a period of time can wear away their own wear and tear, but during this time some of the network of turtle crack cracks have been formed as a source of crack growth, with the