1. 15crmo steel series pearlite structure heat-resistant steel, this material shows superior performance in high temperature environment, and is widely used in key fields such as petrochemical, energy and power, and aerospace. The main reason why this steel has such high thermal strength is that it adds a high content of Cr, C and other alloying elements during the alloying process, which effectively improves the high-temperature strength and oxidation resistance of the steel.
Second, let's take a detailed look at the chemical composition of 15crmo steel. In addition to the iron matrix, this steel contains 12%-1.5% chromium (CR) and 01%-0.4% carbon (c). Chromium is a powerful antioxidant element that forms a dense chromium oxide protective film at high temperatures, effectively preventing further oxidation of steel. Carbon, on the other hand, is combined with elements such as chromium to form a stable carbide, which enhances the hardness and strength of the steel. In addition, a small amount of other alloying elements, such as molybdenum (Mo), vanadium (V), etc., are added to 15CrMo steel, which further improves the high-temperature performance and corrosion resistance of the steel.
It is the addition of these alloying elements that makes the hardening tendency of 15CrMo steel more obvious and the weldability is poor. During the welding process, the steel is prone to defects such as hardening and cracks, which requires some special welding processes and measures to ensure the quality of welding. Usually, the steel needs to be preheated before welding to reduce the thermal stress generated during the welding process; Heat treatment is also required after welding to eliminate residual stresses and improve the performance of the welded joint.
3. Although the weldability of 15CRMO steel is poor, its excellent high-temperature performance and corrosion resistance make it still have a wide range of application value in many fields. In the petrochemical industry, 15CRMO steel is often used in the manufacture of high-temperature and high-pressure pipes, vessels, heat exchangers and other equipment; In the field of energy and power, it is used to manufacture key components such as boiler heating surfaces and steam turbine blocks; In the aerospace sector, 15CRMO steel is used to make critical components such as engines due to its good resistance to hydrogen corrosion.
In order to ensure the safe and reliable application of 15CrMo steel in various fields, the relevant implementation standards and steel plate standards must be strictly followed. In China, the production and quality control of 15CrMo steel follow standards such as GB T 3077-2006 and GB T11251-2009. These standards specify in detail the requirements for the chemical composition, mechanical properties, heat treatment process, non-destructive testing and other aspects of the steel, ensuring the quality and performance of the steel.
4. In addition, in order to further improve the performance and application range of 15CRMO steel, researchers and engineers are constantly exploring and researching new alloying technology, heat treatment process and welding technology. These studies not only help to optimize the performance indicators of steel, but also reduce production costs, improve production efficiency, and provide strong support for the development of related fields.
With its unique high-temperature performance and corrosion resistance, 15CRMO steel-based pearlite microstructure heat-resistant steel shows excellent performance in harsh environments such as high temperature, high pressure, and strong corrosion. Despite its poor weldability, it can still play an important role in many key areas by adopting special welding processes and measures. With the continuous progress of science and technology and the deepening of research, it is believed that the application prospect of 15CRMO steel will be broader.
5. Surface heat treatment
Heat treatment is an extremely effective measure to improve and modify the performance of 15crmo alloy round bar, which plays a very important role in the reliability and economy of the product. The heat treatment of 15CRMO alloy round steel usually includes two categories: ordinary heat treatment (annealing, normalizing, quenching, tempering) and surface heat treatment (surface quenching and chemical heat treatment, carburizing, nitriding, metallurgization, etc.). In mechanical engineering, many machine parts, such as crankshafts, gears, camshafts of internal combustion engines and gears in important reducers, not only require sufficient toughness, plasticity and bending strength in the core, but also require high hardness, high wear resistance and high fatigue strength within a certain thickness of the surface. It is difficult to meet the above performance requirements at the same time by various integral heat treatment methods, and the use of surface heat treatment is the most effective method to achieve these performance requirements at the same time. Surface heat treatment is a heat treatment method that changes the surface properties by changing the structure of the surface layer of 15crmo alloy round steel. Surface quenching is a heat treatment that changes the surface structure without changing the chemical composition of the surface layer. It can be achieved by high-frequency, medium-frequency or power-frequency current induction heating or by flame heating. Its common feature is to try to make the surface of the 15crmo alloy round bar quickly heated to the quenching temperature, and when the heat has not yet reached the core of the part, it is quickly cooled, so that the surface hardness is high, and the core still has high toughness. Chemical treatment is a heat treatment method that changes the surface chemical composition and structure of 15crmo alloy round steel. Chemical heat treatment can be divided into carburizing, nitriding, carbonitriding, metallizing and other methods according to the different elements infiltrated into the surface of 15crmo alloy round steel. It is very effective in improving and improving the wear resistance, corrosion resistance and fatigue resistance of 15crmo alloy round bars. At present, chemical heat treatment has developed rapidly, and new technologies have been applied to many times.