High-strength wear-resistant plates are mainly made of carbide-strengthened austenitic alloy steel. It has good wear resistance below 300℃ and good oxidation resistance below 500℃. It is widely used in the processing of wear-resistant parts of mining, machinery, engineering and other equipment. However, ordinary wear-resistant plates generally have low yield strength, which affects the service life of the material. Therefore, in order to fully utilize the performance potential of the material, obtain ideal performance indicators, and determine the best process parameters, metallurgical workers have studied different solid solution and Effect of aging treatment on the structure and properties of high-strength wear-resistant plates.
The smelting process of high-strength wear-resistant plate for testing adopts non-vacuum induction plus electroslag remelting. Its main chemical composition is shown in Table 1. Before rolling, the steel is heated in a three-stage continuous gas heating furnace. The rolling process is carried out on-site on Φ420mm×3mm, Φ320mm×3mm and Φ250mm×5mm rolling mills respectively, and is rolled into Φ25mm round steel. Due to the difficulty in biting this variety during the rolling process, the heating temperature is controlled by the upper limit temperature of 1160°C. In order to obtain good grain size, the final rolling temperature is controlled at ≤850°C, and air cooling is used for collection after rolling. After rolling, it is annealed in a roller hearth gas furnace, and a box-type resistance furnace is used for solid solution and aging treatment at different temperatures. The mechanical properties were tested on a WDW3300 electronic universal testing machine; the microstructure was observed using a 40MAT metallographic microscope, and the metallographic etching agent was copper sulfate hydrochloric acid aqueous solution.
The results show:
(1) Solid solution treatment has a significant impact on the mechanical properties of wear-resistant plates. The higher the solid solution temperature, the higher the degree of alloying of the matrix, which is more conducive to the precipitation of the age-strengthening phase, especially the strengthening alloy dissolved into the matrix. The content of elements such as W and Mo increases the performance stability of the alloy. However, the solution treatment temperature is too high, which causes the alloy grains to grow rapidly and reduces the strength and plasticity. Based on comprehensive analysis, the solution treatment temperature is determined to be 1170°C.
(2) On the premise that the solution treatment effect is ideal, determining a reasonable aging temperature, that is, holding time, can achieve the best strength index of high-strength wear-resistant plates. The alloy can obtain the best mechanical properties after solid solution at 1170°C and aging at 760°C for 5 hours.
