激光熔凝和熔敷在热轧辊强化中的应用

Applications of laser melting and cladding to hot rolls

为提高热轧辊寿命对球墨铸铁、白口铸铁热轧辊进行了激光熔凝、熔敷实验研究,并对激光处理效果进行了现场轧制实时寿命评估.研究确认:球墨铸铁、白口铸铁激光熔凝小样的硬度随扫描速度的降低和激光功率的增大而提高.分别按轧钢量、磨损量计算,球墨铸铁、白口铸铁激光熔凝热轧辊寿命分别比原来延长50%和15.6%～23.4%.利用激光熔敷技术在白口铸铁热轧辊上可以成功制备无宏观裂纹、气孔和夹杂存在的镍基合金涂层.现场轧制后表面也无宏观缺陷存在,寿命延长18.7%～37.4%.

In order to lengthen the lifetimes of hot rolls, the laser melting and cladding of the hot rolls of spheroidalgraphite and white cast irons were investigated, and lifetimetests of laserprocessed rolls on realtime by online rolling were evaluated. The hardness values of lasermelted samples of spheroidalgraphite and white cast irons increase with the decrease of scanning velocity of laser beam and with the increase of laser power respectively. The lifetimes of the lasermelted hot rolls of spheroidalgraphite and white cast irons have increased by 50% and 15.6%23.4% according to the amount of rolled steels and their wear thickness respectively. Nickelbased alloy coating which is free of macrodefeets of cracks, pores, inclusions,etc. can be fabricated on the substrate of hot rolls of white cast irons by means of laser cladding technique. Also, there are not any macrodefects on their surfaces after rolling, and their lifetimes have increased by 28.7%37.4%.