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1． The material selection analysis of the workpiece for rolling white wall is based on the stress state and service characteristics of the workpiece of the rolling mortar wall under actual working conditions (repetition of high-cycle strong impact, friction, extrusion, and shearing), combined with the current status of wear-resistant materials used in China. After a series of comparative analysis and repeated tests, we selected high manganese steel with strong potential (work hardening ability) under strong impact, friction, extrusion, and shearing conditions as the material for making the workpiece of the rolling mortar wall. 1.1 Determination of the chemical composition of the rolling mortar wall workpiece The wear resistance of high manganese steel is determined by the chemical composition of the steel, the content of inclusions in the steel, the degree of dissolution and segregation of carbides in the steel, the grain size of the steel and the quality of casting. 1.2 The influence of various elements in high manganese steel on its performance Carbon: The wear resistance of high manganese steel castings is not that the higher the carbon content, the more wear-resistant it is, but has a limit value. When the carbon content is >1.4%, a lot of carbides precipitate in the cast state. During water toughening treatment, the carbides cannot be completely dissolved into austenite, and the carbides in interstitial solid solution have also reached saturation. This is not only not good for wear resistance, but also reduces the strength and toughness of the material, making it easy to break during service. silicon: The high silicon content reduces the solubility of carbon in austenite. The precipitation of carbides on the grain boundaries increases and becomes larger. After water toughening treatment, large microscopic looseness is left on the grain boundaries. However, in order to completely eliminate it, the silicon content in the steel is optimally controlled at 0.4-0.6%. The silicon content >0.8% has no significant impact on the various properties of high manganese steel. manganese: Due to the high manganese content of high manganese steel, the as-cast structure of the steel is austenite pot and carbide. After being quenched by heated water at about 1000°C (usually called water toughening treatment). Most of the carbides are solid dissolved in austenite, and the structure of steel is single-phase austenite or austenite plus a small amount of carbides. sulfur: Due to the high manganese content in steel, a large amount of MnS can be generated and discharged from the slag. And because it is smelted in alkaline slag, the sulfur can be smoothly reduced to less than 0.03%. Such low sulfur content has no significant impact on the strength, toughness and wear resistance of steel. phosphorus: Phosphorus alone is rarely dissolved in steel, and often exists in the form of Fe2p and Fe3P on the grain boundaries, which greatly reduces the strength, toughness and wear resistance of the steel. The high carbon content intensifies the precipitation of P on the grain boundaries in the form of eutectic. To ensure performance, the following relationships should be followed: C%=11.27-2.761×P%. During production, the phosphorus content should be controlled to ≤0.08%: Important, complex, thick-walled parts ≤ 0.07%. Based on the above analysis, this test determined that the chemical composition of high manganese steel used to make rolling mortar wall workpieces is ZGMnl3-3, that is, 0.9-1.3% C, 11.0-14.0% Mn, 0.3-0.8% Si, S≤0.05% P≤0.08%. 2． Casting process: See the casting process shown in Figure 1. 2.1 Key points of process design (1) Large car plate modeling process: According to the large outer contour size of the rolling mortar wall workpiece (φ2360 × φ1410.1 × 615.5), a large-scale lathe molding process was designed, using a middle sprue, four radial double-layer injectors to inject molten iron, four top-pressure edge riser feeding and a new multi-factor control casting process. This process is beneficial to the formation of equiaxed crystals in castings and the elimination of columnar crystals. The pass rate of castings cast using this process reaches over 98%. 3. Smelting and pouring process (1) The entire smelting process is carried out in a 3T electric arc furnace. The metal charge is high manganese steel liner return charge, 80% Mn-Fe and 75% Si-Fe are additional alloying elements, and aluminum is inserted and finally deoxidized. To ensure the smelting of high-quality high-manganese molten steel. The melting temperature requirement is greater than 1500°C. (2) Ingredient calculation, feeding sequence and time, temperature control, furnace pre-treatment, box closing and pouring, etc. must be accurate and strictly in accordance with operating procedures. (3) Strictly follow the feeding sequence during smelting, and control the smelting quality in each phase (oxidation phase, reduction phase) according to process requirements. The smelting temperature is required to be greater than 1500°C. (4) Clean slag removal is required during pouring, and rapid pouring is preferred. The pouring temperature is required to be greater than 1480°C. 4． Heat treatment process: Load the cleaned mortar wall workpiece into the heat treatment furnace as required, and perform heat treatment according to the heat treatment specifications shown in Figure 2. Key points of process: Raise the temperature to 300-400°C in 1 hour, then increase the temperature to 1000-1050°C at a rate of 50-80°C per hour to fully austenitize the high manganese steel, keep it warm for 2-3 hours, and then quench it into water for water toughening treatment. The total processing time is 13-14 hours. 5. The industrial test of the rolling mortar wall workpiece was carried out in the standard cone crusher of the mineral processing plant. After four months and 15 days of practical application, it has been shown that the selenium mortar wall workpieces produced by our factory (compared with purchased parts) have the following significant characteristics: (1) The surface is smooth and free of casting defects such as sand adhesion, sand inclusion, pores, shrinkage cavities, etc. (2) High intrinsic quality, with good ability to withstand strong load and high cycle impact, friction, extrusion, shearing, etc. (3) The service life exceeds that of similar purchased products. 6． in conclusion: (1) Reasonable material selection, advanced casting technology and reliable control measures are the keys to producing high-quality rolling mortar wall workpieces. (2) The improvement of the heat treatment process is a reliable guarantee to obtain rolling mortar wall workpieces that can withstand alternating loads such as impact, friction, extrusion, and shear. (3) This scientific research product has achieved good application results in saving the cost of the mineral processing plant by 350,000 yuan per year through practical application.