What is the difference between nitridation and heat treatment of mold steel?
Nitridation is the surface coating of parts. Mainly some of the slider structure of the mold parts, to improve the strength of the surface.
Heat treatment is the overall treatment of steel, steel can enhance the physical properties. Usually for the whole cavity and large inserts.
Nitridation is also one of the many methods of heat treatment, mainly for some parts need to improve the hardness of quenching, wear resistance, but also afraid of deformation of the product carried out a heat treatment method. The advantage of nitridation is the low temperature, small part deformation, high surface hardness.
Heat treatment is the heating of the workpiece to a certain temperature after the insulation into the liquid to cool, so as to form a layer of dense surface, the hardness of the oxide film. Nitridation is the surface nitriding treatment. They belong to the surface heat treatment. Metal heat treatment is mechanical In the manufacture of one of the important processes, compared with other processing technology, heat treatment generally does not change the shape of the workpiece and the overall chemical composition, but by changing the internal microstructure of the workpiece, or change the chemical composition of the workpiece surface, given or improved The use of the workpiece performance.
In order to make the metal workpiece with the required mechanical properties, physical properties and chemical properties, in addition to rational selection of materials and a variety of forming process, the heat treatment process is often essential. Steel is the most widely used material in the machinery industry. The microstructure of steel is complex and can be controlled by heat treatment. Therefore, the heat treatment of steel is the main content of metal heat treatment. In addition, aluminum, copper, magnesium, titanium and its alloys can also change their mechanical, physical and chemical properties by heat treatment to achieve different performance.
Nitriding refers to a chemical heat treatment process in which nitrogen atoms penetrate into the surface of a workpiece at a certain temperature. The nitrided articles have excellent abrasion resistance, fatigue resistance, corrosion resistance and high temperature resistance. Aluminum, chromium, vanadium and molybdenum in the traditional alloy steel are very helpful for nitriding. These elements in the nitriding temperature, and the initial nitrogen atoms in contact, it generates a stable nitride. In particular, the molybdenum element is not only used as a nitride element, but also as a decrease in the brittleness occurring at the nitriding temperature. Other elements in the alloy steel, such as nickel, copper, silicon, manganese, nitriding properties are not much help. In general, if the steel contains one or more nitride-forming elements, the effect of nitriding is relatively good. Aluminum is the strongest nitride element, containing 0.85 ~ 1.5% aluminum nitriding results the best. In chromium chrome steel, if there is sufficient content, can also get very good results. But there is no alloy of carbon steel, because of its formation of nitriding layer is very brittle, easy to peel off, not suitable as nitriding steel.