大型支撑辊的堆焊修复工艺及应用

大型支撑辊重量大、辊径大、辊面长、耐磨层厚,采用传统的堆焊工艺修复Cr3~Cr5大型支撑辊难度大,母体金属与堆焊层容易在堆焊时发生相变,导致开裂。另外,传统的轧辊堆焊修复工艺不合理,修复的轧辊力学性能较差,限制了轧辊的使用寿命,大量报废的轧辊尤其是大型轧辊长期堆积在轧钢厂内,增加了生产成本,造成了极大浪费。为此,开展了大型热轧Cr3~Cr5支撑辊及大型冷轧Cr3支撑辊焊材制备、堆焊工艺及修复技术研究。技术实施表明,修复后的支撑辊使用寿命达到新轧辊的寿命,每支堆焊修复支撑辊上机使用至报废尺寸,至少可循环堆焊修复3次,使支撑辊单项辊耗成本在每个循环周期内降低40%~60%,同时解决了大型支撑辊焊接性能不稳定的难题。

Heavy back-up roll surfacing welding repair process and application

Due to its large weight,large diameter,long roll surface and thick wear-resistant layer,repairing Cr3-Cr5 heavy back-up roll is difficult with traditional surfacing technology.The metal in surfacing layer are prone to phase change during surfacing,and lead to cracking.In addition,the traditional repair process of roll surfacing is unreasonable,and the repaired roll has poor mechanical properties,which limits the service life of the roll.A large number of scrapped rolls have accumulated in the rolling mill for a long time,which increases the production cost and causes great waste.Therefore,the welding material preparation,surfacing technology and repairing technology of heavy Cr3-Cr5 back-up roll for hot rolling and heavy Cr3 back-up roll for cold rolling were studied.Technology implementation show that the repaired back-up roll service life can be met the new roll life,the recycled surfacing at least three times of roll size used to scrap.The consumption cost in each cycle could be reduced by 40%-60%,and the problem of unstable performance of repaired heavy back-up roll could be resolved.