1、 Technical requirements for heat treatment of bucket teeth and shovel teeth of excavators
The purpose of heat treatment of zgmnl3 and zgmnl3re high manganese steels is to obtain a single austenite structure after water toughening treatment. Carbides should be avoided as far as possible (if they exist, the strength and wear resistance of the steels will be seriously reduced). In addition, low alloy steel is also used to make bucket teeth or shovel teeth. In order to pursue large wear capacity and prolong service life, the method of increasing the thickness of tooth tip is adopted, and the heat treatment process of quenching and low temperature tempering is adopted. The lath martensite (dislocation martensite) obtained has quite high strength, hardness, high plasticity and toughness, and its comprehensive mechanical properties are high, The hardness of the surface and core is 44-52 HRC.
2、 Heat treatment process
In order to obtain the required microstructure, the common heat treatment process is solution treatment (water toughening treatment). The solution temperature of zgmnl3 steel is 1050 ~ 1080 ℃, and the zgmnl3re is 1000 ~ 1030 ℃. The holding time should be determined according to the size, thickness and charging capacity of the parts, The carbide is completely and fully dissolved in austenite. After heat preservation, it is quickly cooled to form a single austenite structure, which is soft and tough, and no carbide precipitation is allowed. The heating equipment is usually large high temperature box furnace or salt bath furnace. Due to the low thermal conductivity, in order to ensure the consistency of internal and external temperature difference and prevent cracking, it should be preheated at 600 ~ 650 ℃ and the solution holding time should be reduced.
Excavator parts production
Add：Ma Jia Cun He Xi, Lutou Town, Longkou City, Shandong Province