AISI 52100 Bearing Steel | 100Cr6 | DIN 1.3505 | SUJ2

AISI 52100 belongs to bearing steel as per ASTM A295.As the most widely used high carbon chromium bearing steel with less alloy content, good performance, AISI 52100 steel has good comprehensive performance, with high and uniform hardness, good wear resistance, high contact fatigue performance after quenching and tempering.

AISI 52100 steel has good hot working performance, medium cold working plasticity, good machinability after spheroidizing annealing, general cutting performance,but poor in weldability,aslo has high sensitivity to white spot, and easy to temper brittleness.

AISI 52100 Forged round steel with annealed condition

AISI 52100 BEARING STEEL SUPPLY FORM & SIZE & TOLERANCE

Hot Forged Round bar:Φ80-Φ1000mm

Hot Rolled Round bar:Φ16-Φ130mm

Hot Forged Square bar: Max Thickness:500mm

Flat bar/Blcoks:Thickness :120-800mm ,Width:120-1500mm

Surface Finish	Black-Forged	Black-Rolled	Turned	Grinding	Polished	Peeled	Cold Drawn
Tolerance	(0，+5mm)	(0，+1mm)	(0，+3mm)	Best h9	Best h11	Best H11	Best H11

WHAT IS BEARING STEEL?

Bearing steel is the steel used to make balls, rollers and bearing rings. Bearing steel has high and uniform hardness and wear resistance, as well as a high elastic limit. The requirements for the uniformity of the chemical composition of the bearing steel, the content and distribution of non-metallic inclusions, and the distribution of carbides are very strict, and it is one of the most stringent steel grades in all steel production.

Bearing Steel Basic Requirements

Strict chemical composition requirements
Higher dimensional accuracy requirements
Particularly stringent purity requirements
Strict macroscopic and microscopic structure requirements
Particularly stringent requirements for surface defects and internal defects
Strict carbide inhomogeneity requirements
Strict surface decarburization layer depth requirements

Bearing Steel Performance Requirements

High contact fatigue strength
High hardness
High wear resistance & Low friction coefficient
High elastic limit
Good impact toughness & Fracture toughness
Good dimensional stability
Good rust resistance
Good cold and hot processing properties

Bearing Steel Main Classification

Fully hardened bearing steel

Typical Grades：AISI 52100,GCr15,100Cr6,SUJ2

Surface hardened bearing steel

Typical Grades：AISI 8620,SNCM220,SNCM420,20NiCrMo2-2,AISI 4118,AISI 4320

Stainless bearing steel

Typical Grades：SUS440C,AISI 440C

High temperature bearing steel

Typical Grades：M2,W18Cr4V

AISI 52100 STEEL CHEMICAL COMPOSITION

Grade	C	Si	Mn	P	S	Cr	Ni	Mo	Cu
52100	0.93-1.05	0.15-0.35	0.25-0.45	≤0.025	≤0.015	1.35-1.60	≤0.25	≤0.1	≤0.3
100Cr6/1.3505	0.90-1.05	0.15-0.35	0.25-0.45	≤0.03	≤0.025	1.35-1.65	≤0.3	-	≤0.3
SUJ2	0.95-1.10	0.15-0.35	≤0.5	≤0.025	≤0.025	1.3-1.6	-	-	-

AISI 52100 STEEL RELATED STANDARD & EQUIVALENT GRADE

CHINA/GB 18254:GCr15

Germany/DIN 17230:100Cr6/1.3505

JAPAN/JIS G4805:SUJ2

UK/BS970:535A99/EN31

AISI 52100 BEARING STEEL FORGING

Initial Forging Temperature：1050-1100℃
Final Forging Temperature：800-850℃
Forging Ratio：above 4:1
Post-Forging Treatment: AISI 52100 steel is air-cooled to 700°C after forging and cooled in sand. After forging, the organization is flaky pearlite, allowing the appearance of fine network carbides.

Once the forging process of AISI 52100 steel is improper, for example, the final forging temperature is too high and the cooling rate after forging is too slow, the carbides will obviously precipitate along the austenite grain boundaries, resulting in the formation of coarse network carbides.

Another example is that the final forging temperature is too low, the carbides precipitated along the grain boundaries will be elongated along the deformation direction together with the austenite grains, so that the carbides are striped.

Both of these two types of carbides cannot be changed by the spheroidizing annealing process, and must be eliminated by the normalizing method before the spheroidizing annealing, so as to ensure the spheroidizing annealing quality and give the material good heat treatment properties.