Alloy Steel 40Mn2 Item: Alloy Steel 40Mn2 Standard: GB/T 3077——2008 Equivalent grades: GB/T 3077——2008: 40Mn2 AISI/ASTM: 4130 EUROPEAN: 25CrMo4 JIS: SCM420 Introduction: 40Mn2 alloy steel is widely used for making components of small cross section, requiring certain strength and good toughness. It is kind of low alloy steel, which contain a certain amount of alloy elements, like Cr and Mo, which can improve the hardness and toughness of steel. 40Mn2 alloy steel is most used in manufacturing small and medium-sized plastic moulds and all kinds of engineering components. Its equivalent steel number is 1.0503. Application: Alloy Steel 40Mn2 is mainly used for manufacturing components of small cross section, requiring certain strength and good toughness. Its equivalent steel number is 1.0503. Typical application for 40Mn2 include crank, axle, automobile industry and diesel engine parts like connecting rod, shaft, spindle, valve and piston, etc. Heat treatment for 40Mn2 Alloy Steel: 1.Normalizing Temp: 850-900 ℃, Cooling: air cooling 2.Annealing Temp: 800-850 ℃, cool in furnace 3.Quenching Temp: 950-1000 ℃ A, Oil Cooling B, Air Cooling 4.Tempering Temp: 300-450 °C, Cool in air 40Mn2 Alloy Steel Mechanical Property: Tensile strength (Mpa): 900 Ultimate Strength (Mpa): 815 Elongation rate (%): 13 Max Hardness (hb): 197(note: Mn2 steel hardenability is relatively low) Note: Machinability is significantly lower than that of plain carbon steels. 40Mn2 Chemical Composition (Typical): C(%): 0.38-0.45 Si (%): 0.17-0.37 Mn (%): 0.8-1.10 P(%): ≤0.035 S(%): ≤0.035 Cr(%): 0.3-0.5 Mo(%): 0.15-0.2 B(%): 0.0005-0.0035.
: Alloy Steel 40Mn2 is a medium carbon manganese steel, containing 0.38-0.45% Carbon, 0.30-0.50% Chromium, 0.15-0.20% Molybdenum, along with smaller quantities of some other elements. 40Mn2 is a popular alloy steel used for so many general purpose applications demanding higher wear resistance and strength. This steel large cross-sectional with uniform thickness and good mechanical properties, such as high tensile strength and good toughness, making it an ideal material for components with small load-bearing requirements.
40Mn2 steel is most commonly used to manufacture components of small cross-section, such as shafts, bolts, valves, and pistons. It is also used to produce components like connecting rods and spindles in automobile industry and diesel engines. It is also in reliability engineering requiring good wear resistance, but high strength. Forging and heat treatment of 40Mn2 alloy steel can result in improved performance, corroded surfaces and improved fatigue resistance.
40Mn2 alloy steel is relatively versatile and performs well in either heated or hot rolled condition, making it useful for a variety of manufacturing processes. It has a good machinability rate and when it comes to welding, this steel is not really suitable as it has poor weldability. It is a low alloy steel which makes it highly resistant to corrosion, making it suitable for many applications which require a good corrosion resistance property.
40Mn2 alloy steel is the traditional Chinese military steel grades, 40Mn2 is similar to the international standardization medium-carbon high manganese steel, with the advantages of both of them. It not only has a higher hardenability, but also has a higher impact toughness and better mechanical properties. In addition, 40Mn2 alloy steel has good machinability and weldability, no additional thermal treatment, and excellent dimensional stability, after being formed and automatically cooled. As a result, Alloy Steel 40Mn2 is often used in the manufacture of molds, and engineering components requiring good toughness, as well as components under mid-load tires and requiring a certain level of strength.
Alloy Steel 40Mn2 has a good performance in heat treatment. Normalizing temperature at 850-900°C, cooling in air. Annealing temperature at 800-850°C, cool in the furnace. Quenching temperature at 950-1000°C, A oil cooling, B air cooling. Tempering temperature at 300-450°C, cooling in air. The mechanical properties of Alloy Steel 40Mn2 are: tensile strength 900MPa, ultimate strength 815MPa, elongation rate 13; maximum hardness 197HB(Note:The hardenability of 40Mn2 is relatively low).
In conclusion, Alloy Steel 40Mn2 is a medium carbon manganese steel with excellent wear resistance, good hardness and strength. 40Mn2 is an ideal material choice for parts and components requiring small load bearing and superior wear resistance. It is also excellent for components in need of high strength and reliability, such as connecting rods and spindles in automotive industry, engine parts and molds that require good wear-resistance. Heat treatment and forging of 40Mn2 can result in excellent performance, improved size, fatigue proof and improved corrosion resistance.
