Hot Roller With High Nickel Chrome Molybdenum Iron Inoculation And Alloying

A newly-developed multi-component modifier is designed and employed to the high Ni-Cr-Mo cast iron. The effects of modification on microstructure and mechanical properties have been investigated, and the mechanism of the modification was proposed and discussed from different aspects. Influence of Ni and microalloying elements on microstructure and mechanical properties of modified high Ni-Cr-Mo cast iron was studied. Meanwhile, the effects of the matrix, load and sliding speed on wear resistance of the modified high Ni-Cr-Mo cast iron were also discussed. The results are as follows:(1) Modification treatment makes the matrix and eutectic carbides finer in structure, the continuous net-like structure of carbides are broken partially, and the ledeburite carbides decreased and become blocky. Such microstructure changes lead to mechanical property improvement in the cast specimen with its hardness increased from43to49HRC, impact toughness from6.3to7.8J/cm2.(2) With Ni3.8%, hardness and impact toughness of the modified high Ni-Cr-Mo cast iron achieve good matching, impact toughness9J/cm, and hardness of58HR.C; Microalloying elements Nb and Ti have beneficial in hardness increasing, with little effect of improving the impact toughness when added separately, but composite adding help improve the impact toughness; heat treatment:850°C×1.5h+330°C x2h air-cooled, can significantly improve impact toughness and hardness of modified high Ni-Cr-Mo cast iron, beneficial to the improvement of mechanical properties.(3) The sliding friction coefficient and abrasive wear weight loss decreased after modification treatment. For the modified high Ni-Cr-Mo cast iron, the sliding wear test in the chosen load and sliding speed illustrate that the bainite matrix show better wear resistance than the austenite.