Metallographic diagram of 40Mn2

40Mn2 Steel

40Mn2 steel is a kind of medium-carbon steel mainly for alloy construction. This kind of steel has a medium carbon content between 0.37% and 0.45%, and the Mn content is between 1.50% and 1.70%. 40Mn2 steel is one of the most important alloy steels in Chinas machinery industry, and it plays a very important role in improving a companys mechanical and equipment development.

40Mn2 steel has high strength, good toughness and plasticity, good tempering effect, temper brittleness and is easy to overheat. Its performance is close to 45 steel, but the price is lower than 45 steel. It has greatly reduced the manufacturing cost and improved the economic profitability of the screw, clutch sleeve, bushing and other parts manufacturers.

The microstructure of 40Mn2 steel usually contains austenite, ferrite and pearlite, and the amount of pearlite is greater, making it a medium-size Pearlitic steel. This type of steel has a higher hardness, a higher strength and a higher plasticity, and it also has a certain degree of toughness, making it an ideal choice for many applications.

When 40Mn2 steel is used in applications, it is necessary to conduct an analysis of its chemical composition and mechanical properties. For the chemical analysis of 40Mn2 steel, it includes the C, Mn, Si, P and S content. The C content should be between 0.37% and 0.45%, and the Mn content should be between 1.50% and 1.70%. The P content should be lower than 0.035%, and the S content should be lower than 0.050%. When analysing the mechanical properties, the strength and hardness of the steel should be taken into account. The tensile strength of 40Mn2 steel should exceed 630Mpa, while the impact toughness should exceed 24J/cm².

In order to obtain the best performance of a 40Mn2 steel application, it is necessary to perform a metallographic analysis to determine its structure. Metallographic inspection can accurately provide information about the structure and properties of the steel, so it is widely used to analyze the quality of 40Mn2 steel. Through metallographic analysis, the following aspects of 40Mn2 steel can be determined: grain size, grain shape, phase morphology, inclusion rate, phase composition and other information.

In general, 40Mn2 steel is widely used in machinery, auto parts, locomotives, financial machinery, agricultural machinery and other areas. It provides good performance and a lower price than 45 steel, making it a great choice for many applications. In order to obtain the best performance for 40Mn2 steel applications, it is necessary to conduct careful analysis and testing, to ensure that its mechanical strength, toughness and plasticity can meet the requirements of the application.

20Mn2 is a kind of steel material with medium carbon content, good plasticity and toughness, high strength, good cold and hot workability, good machinability and wear resistance, good welding performance, and after quenching and tempering, its mechanical properties such as strength and hardness are better.

The metallographic structure of 20Mn2 is adjusted by the experimental heat treatment on the steel. The adjustment is mainly aimed at changing the pearlite structure of ferrite, changing micro-alloying elements and improving the plasticity of steel. The as-solidified microstructure of 20Mn2 is pearlitic microstructure with ferrite as the matrix. The internal structure of the microstructure consists of primary ferrite, cementite (Fe3C spar) and occasionally a small amount of pearlite. The microstructure is evenly distributed, the pearlite is fine, and the number of pearlite is large. With the increase of heat treatment process, the number of pearlite decreases and the ferrite increases, and the large pearlite is mostly changed into fine and ultra-fine lath. The interaction between cementite and ferrite is enhanced, and the nodularity of the pearlite is improved.

20Mn2 has good machinability after heat treatment and quenching tempering, and its cold and hot forming performance is also good. It is mainly used in the production of camshafts, connecting rods, link shafts and other mechanical parts, and can also be used in the production of eye plates, wheel mounting plates and wheel hubs.