Heat Treatment Process Of The Knife Circle Material Which Possess Grads Hardness

In order to improve the service life of the knife circle part in the shield construction machine, we studied and analyzed the failure forms of the knife circle parts during use and think that too much focus on increasing material hardness and overlook toughness is the main reason of its failure. Based on analyzing material and its heat treatment process, we made improvement of heat treatment process and put forward the new heat treatment method. Its process is as follow:a heat device is set out in the circle inside diameter and a cooling device is set out in the knife circle outside diameter in order to establish a gradient distribution of temperature field. Using this heat treatment process, one part with a gradient hardness distribution can be produced. A new heat treatment equipment for experiment was design and produced. The heat treatment process of material and microstructure and property analysis was carried out.