Comparison of the performance of two major types of bearing steel materials

Bearing steel is the most common material used in bearings. There are two types of materials commonly used in bearing steel: carburized bearing steel (G20Cr2Ni4A) and high-carbon chromium bearing steel (GCr15/GCr15SMn/GCr18M0). According to specific understanding, China Bearing Network shares the performance comparison of these two bearing steel materials. I hope you can be sure when buying bearing materials and buy the most suitable bearing steel.

Carburized bearing steel (G20Cr2Ni4A)

G20Cr2Ni4A bearing steel is a high-quality alloy carburizing steel (low carbon C: 0.17~0.23) used to manufacture bearing parts. Carbide steel is used for bearing parts made of this type of steel, after heat treatment such as carburization, rate fire, tempering, etc. After the process, the surface has a high hardness (hardness>HRC60) and a certain abrasion resistance and high contact fatigue resistance strength, low carbon C: 0.17~0.23 to ensure that the core has good toughness (hardness>HRC33 -48). This surface hardened core has the characteristics of toughness, making carburized bearing steel particularly suitable for stable operation under conditions of large impact loads. In short, the advantages of carburized steel bearings are:

1. The surface retains the state of compressive stress after carburizing and quenching, and has good fatigue resistance.

2. Strong ability to withstand impact load, the surface hardened layer has micro cracks and it is not easy to expand to the inside. The surface has a higher hardness and the core hardness is lower (generally 35HRC ~ 40HRC), compared with high-carbon chromium bearing steel, has better impact toughness of the core.

3. The depth and concentration of carburization can be adjusted as required.

4. Not limited by the size and wall thickness of bearing parts.

High carbon chromium bearing steel (GCr15/GCr15SMn/GCr18M0)

High-carbon chromium bearing steel is a high-carbon alloy steel containing chromium 1.30~1.65%. Its characteristics are: the microstructure after heat treatment is relatively uniform and stable, the hardness is high and uniform, the wear resistance is good, the contact fatigue strength is high, and it has good Dimensional stability and corrosion resistance. After spheroidizing annealing, its cutting performance is good. This kind of steel can meet the use requirements of bearings operating under general working conditions.

1. High-carbon chromium bearing steel is widely used in the world. The most commonly used grades are GCr15 and GCr15SiMn. The amount used in our country accounts for more than 80% of the total bearing steel. The performance of these two steels is basically the same, but the GCr15SiMn steel Hardenability is better than GCr15 steel, so for larger size bearing parts, GCr15SiMn steel should be used.

2. GCr15 bearing steel is widely used for the manufacture of engine bearings, machine tools, motors, etc. used in automobiles, tractors, tanks, aircrafts, etc. as well as bearings for railway vehicles, mining machinery, and general machinery.

3. GCr15SiMn bearing steel is mainly used to manufacture bearings with large wall thickness, such as various large and extra large bearings, which are mostly used in heavy-duty machine tools and rolling mills under working conditions without large impact loads.

4. Due to the high crack sensitivity of GCr15SiMn steel and poor impact toughness, the thick wall bearings with impact load cannot fully meet the requirements for use. The Ministry of Railways first proposed that passenger car bearings are not allowed to use GCr15SiMn steel, as well as those with large wall thickness Rolling mills and mining bearings are also subject to limited use under conditions where the impact load is large. Has now developed GCr18Mo high hardenability steel, and wear resistance. Its performance is superior to GCr15SiMn steel, which can be used in railway bearings, rolling mill bearings, mining machinery bearings instead of GCr15SiMn steel.