After CNC machining, Steel Forging, casting, we can do the surface hardening
After CNC machining, Steel Forging, casting, we will do the surface hardening. Commonly used surface hardening methods mainly include carburizing, nitriding, hard anodizing, chrome plating, surface hardening, and metal infiltration.
Carburizing of steel is to heat or heat the steel parts with low carbon content in the carburizing medium, so that carbon atoms penetrate into the surface to obtain a certain surface carbon content. After quenching, the surface layer with high carbon content is very high. However, the low hardness of the core with low carbon content still has good toughness. The aim is to achieve high surface hardness, wear-resistance and high contact fatigue strength and bending fatigue strength. Mainly used for parts subject to wear, alternating contact stress or bending stress and impact load, such as shafts, gears, camshafts, etc. These parts require high hardness on the surface and sufficient strength and toughness in the core.
Nitriding means that the alloy steel (generally containing Al, Cr, Mo) is heated in a flow of anhydrous ammonia (NH3) at a temperature of about 500 ° C to 570 ° C for a long time to form a high hardness and corrosion resistance on the surface of the steel. Nitride (mainly Fe2N, Fe3N, Fe4N). There are generally gas nitriding, liquid nitriding and glow ion nitriding.
The anodization of aluminum is based on aluminum or aluminum alloy as an anode, and the lead plate is used as a cathode to electrolyze in the electrolyte to form an oxide film on the surface. After anodization, the aluminum surface can form an oxide film having a thickness of several to several hundred micrometers. The surface of this oxide film is porous honeycomb, and its corrosion resistance, wear-resistance and decorative properties are significantly improved and improved compared with the natural oxide film of aluminum alloy. Anodized films of different properties can be obtained using different electrolytes and process conditions.
Hard Chrome Plating
The hardness of chromium can reach 800~10OOHV, which is the hardest metal. It has strong passivation properties and is quickly passivated in the atmosphere. Therefore, the chromium layer is stable in the atmosphere and can maintain its luster for a long time. It is in corrosive media such as alkali, nitric acid, sulfide, carbonate and organic acid. Very stable, but soluble in hydrohalic acids such as hydrochloric acid and hot concentrated sulfuric acid.
Surface quenching refers to a heat treatment process in which the surface of a workpiece is rapidly heated to a quenching temperature within a certain depth range, and then rapidly cooled to achieve quenching purposes within a certain depth range. The purpose is to obtain martensite structure in a certain depth range of the workpiece surface, while the core still maintains the state of the structure before quenching (tempered or normalized state), so that the surface is hard and wear-resistant, and the heart has sufficient plasticity. And resilience. Mainly used for machine parts made of medium carbon quenched and tempered steel and ductile iron