Failure of scourge-type reamer and feasibility of strengthening by flame spray welding NiWC coatings

In order to solve the problem of high-priced and short-lifetime of straw stubble returning machinery, the Ni60 and NiWC coatings were prepared on the surface of 45^# steel specimens by flame spray welding. The failure mechanism of scourge-type reamer was analyzed. The worn macro-appearance and bonding status between substrate and coatings were observed with metallographic microscope. Wear test was conducted using self-made testing machinery which can imitate the actual working condition of scourge-type reamer. The abradability of strengthened coatings, which were made by quench and tempering 65Mn and flame spray welding Ni60 and NiWC alloy, was contrasted. The feasibility of flame spray welding NiWC coatings used to strengthen scourge-type reamer was discussed. The results show that the coatings of flame spray welding NiWC have high anti-wear performance and can be used to strengthen and repair the scourge-type reamer of straw stubble returning machinery.