Can 20Mn2 replace 20Mn

20Mn2 belongs to the national standard alloy structural steel, and the executive standard: GB T 3077-201520Mn2 has medium strength. High plasticity during cold deformation, good low temperature performance, acceptable weldability and machinability.

Compared with carbon steel with corresponding carbon content, its hardenability is higher, and the critical hardening diameter in oil is up to 4 15 mm, but it has a tendency to overheat, decarburization and tempering brittleness during heat treatment. It is used to manufacture carburized parts with low requirements for the surface and core, and the cross-sectional diameter is <50mm, such as carburized pinions, small shafts, piston pins, cross pin heads, diesel engine sleeves, valve ejector rods, gearbox levers, steel sleeves, etc. In addition, this steel can also be used to make riveting and weldments, screws, nuts, etc. in the hot-rolled and normalized state.

The chemical composition of 20mn2 is shown in the figure below

There should be no problem.

20Mn2: C-C: SiliconSi: Manganese, Phosphorus, P: Sulfur: Chromium, Cr: Nickel, Ni: Copper, Cu:

20Mn: Carbon C: Silicon Si: Manganese Mn: Sulfur S: Structural Steel Phosphorus P: Chromium Cr: Nickel Ni:

20mn2 is a low-alloy knotted steel, mainly because the mn content is more than 20mn.

20Mn2: Tensile strength 785MPa

Yield limit 590MPa

Elongation 10%.

Section shrinkage 40%.

Impact absorption work 47aku2 j

Hardness: 187HB unheat-treated

20Mn:Tensile Strength B (MPa): 450(46)Yield Strength S (MPa): 275(28)Elongation δ5 (%24

Cross-sectional shrinkage 50

Hardness: Unheattreated, 197HB

From the perspective of mechanical properties, the tensile strength of 20mn2 is better than that of 20mn, but the toughness is worse. The brittleness of 20mn2 is larger, and if the toughness requirements are not high, 20mn2 can be used instead of 20mn.

The mn content of 20mn2 and 20mn is different, whether it can be replaced depends on the specific problem of specific analysis, their mechanical properties may be fine, but their properties such as hardenability are different. It depends on the use of the material.

20Mn2 is an alloy structural steel with medium strength, high plasticity during cold deformation, good low temperature performance, good weldability and machinability. The main characteristics of 20mn2 alloy structural steel: it has medium strength.

High plasticity at cold deformation, good low-temperature properties, acceptable weldability and machinability. Compared with the carbon steel shirt with the corresponding carbon content of the collapse bond, its hardenability is higher, and the critical hardenability diameter in the oil is 4 15mm, but it tends to be overheated, decarburized sensitive and tempered brittle during heat treatment. This steel has a high tensile strength due to its proper hardenability, homogeneous soxtenite, schemite bainite or fine pearlite after proper metal heat treatment.

Application example of 20mn2 alloy structural steel: used to manufacture cross-sectional dimensions and diameters that do not require a high surface and center. Chemical Composition of 20Mn2 Alloy Structural Steel:

Silicon-manganese-phosphorus: sulfur content: chromium cr:

Nickel Ni: Copper Cu: Mechanical properties of alloy structural steel:

Tensile strength: 785MPa, yield limit, 590MPa, elongation: 10%, area shrinkage: greater than or equal to 40%, impact absorption work: 47AKU2 J, hardness: 187HB

<>20mn2 is an alloy structural steel. It has moderate strength, can work at low temperatures, and has the characteristics of high plasticity during cold deformation. After heat treatment, sostenite, bainite or very fine pearlite will appear, and the tensile strength is higher, so it also has higher hardenability than other types of steel, but it should be noted that such steels will have negative effects when heat treated.

Therefore, it is often used to manufacture carburized parts, such as piston pins with low requirements, diesel engine sleeves, etc., and in special conditions, it can also be made into screws and nuts.

Material name: high-quality carbon structural steel.

Grade: 20mn

Characteristics and scope of application: high manganese low carbon permeability steel, similar to 15mn steel. Low-carbon carburizing steel with high manganese content (W mn, its strength due to high manganese.

Plasticity. The machinability and hardenability are slightly higher than that of 15 steel, and there are fewer soft spots formed on the surface during carburizing and quenching, so carburizing is appropriate. Carbonitriding treatment obtains the comprehensive properties of surface wear resistance and good core toughness.

Good toughness after hot-rolled or normalizing treatment. It is suitable for gears, crank shafts, brackets, twisted chains, screws, nuts, riveting and welding structural parts, manufacturing oil tanks, etc. Farm tools in cold regions, such as cream jars, etc.

Carbon C: Silicon Si:

Manganese mn:sulfur s: phosphorus p:

Chromium cr:

Nickel ni:

Copper Cu: Tensile Strength B (MPa): 450(46)Yield Strength S (MPa): 275(28)Elongation δ5 (%24

Cross-sectional shrinkage 50

Specimen size: The specimen size is 25mm

Heat treatment specifications and metallographic structure:

Heat Treatment Specification: Normalizing, 910. Difference Between 20mn and 20mn2:

The chemical composition of these two steels (the same carbon content, different manganese content), mechanical properties, and heat treatment methods are different, and the main differences are as follows: 20mn is a high-quality carbon structural steel chemical composition (%)c:

:Mechanical Properties:

Tensile Strength 450MPaYield Limit 275MPaElongation 24%Section Shrinkage 50%Heat Treatment: Normalizing, Carbon, Nitriding 20Mn2 Alloy Structural Steel Chemical Composition (%)C:

Mechanical properties: tensile strength 785MPa, yield limit 590MPa, elongation 10%, section shrinkage 40%, impact absorption work 47AKU2 J heat treatment:

Quenching (water, oil quenching), tempering (water, air cooling), carburizing.

50mn2, alloy structural steel.

Standard: GB T 3077-1999

Main characteristics] This is a kind of high-strength medium carbon quenched and tempered manganese steel, which has high strength, elasticity and wear resistance, and high hardenability, with a critical quenching diameter of 10 28mm in oil and a critical quenching diameter of 24 49mm in water, and the machinability is acceptable. The steel can obtain higher comprehensive mechanical properties after quenching and tempering, but it has overheating sensitivity and tempering brittleness during heat treatment, and also has a tendency to produce cracks when water quenching, and is sensitive to white spots, poor weldability, and low cold deformation plasticity.

Application example] This steel is usually used after quenching and tempering, and is used to manufacture parts that work under high stress and wear conditions, and the performance of steel is similar to that of 45cr when manufacturing parts with a diameter of less than 80mm; It can also be used after normalizing and high temperature tempering, and can be used to manufacture parts with medium load and large cross-sectional size. For example, it is used as a spindle, shaft and large gear in rolling bearings on heavy machinery; transmission spline shafts in automobiles and mandrel subjected to shock loads; Generally, it is used as gears, worms, gear shafts, crankshafts, connecting rods, etc.

In addition, before impermeability, this steel can also be used to make leaf springs and flat coil springs.

The plasticity is medium during cold deformation, and the machinability and weldability are acceptable, but the parts need to be preheated to more than 200 before welding. The wire drawing, cold heading and heat treatment process has good performance, high hardenability, critical quenching diameter in oil, and small quenching deformation, but there are overheating, decarburization sensitivity and tempering brittleness. The steel has high strength, toughness and wear resistance after quenching and tempering, and the static strength and fatigue strength are also good.