As high strength carburized gear steel, 19CN5 contains 0.8% Cr and 0.8% Ni elements as strengthening alloy elements as per French Standard.
19CN5 steel has good forging properties, machinability, high wear resistance, high toughness and fatigue resistance.At the same time, it has a certain strength, which can be said to be one of the steel grades with better combination of strength and toughness.
After carburizing and quenching, the surface of 19CN5 is hard and wear-resistant, while the core is tough and has the advantages of high low-temperature impact toughness.As a typical grade of Cr-Ni series gear steel, 19CN5 is used to make the automobile transmission parts and its matching accessories,such as medium module gears,and gear shafts.
19CN5 STEEL CHEMICAL COMPOSITION
19CN5 STEEL RELATED STANDARD & EQUIVALENT GRADE
China | GB 3077:20CrNi
Germany | DIN :19CrNi5
19CN5 STEEL FORGING
- Initial Forging Temperature：1200℃
- Final Forging Temperature：800℃
- Forging Ratio：above 4:1
- Post-Forging Treatment:According to our experience, 19CN5 should be cooled slowly after forging, and annealing heat treatment should be done in time for subsequent machining.
QUICK FAQS FOR 19CN5 STEEL
What is the oxygen content requirement of 19CN5 steel?
The oxygen content in steel is an important factor affecting the fatigue life. According to the data, when the oxygen content is reduced from 25 ppm to 11 ppm, the contact fatigue strength can be increased by 4 times.
For 19CN5 steel, production processes such as refining and slagging, VD degassing, argon blowing and soft stirring are required to ensure that the oxygen content of 19CN5 steel is <20ppm, and the best below 15pppm.
What is the hydrogen content requirement of 19CN5 steel?
Hydrogen is an important root cause of white spots, and it is extremely important to strictly control the hydrogen content in steel.For 19CN5 steel, it is necessary to ensure sufficient VD vacuum degree and vacuum time, and control the hydrogen content below 2ppm.
Why does 19CN5 steel have a narrow hardenability band requirement？
The 19CN5 gear steel with narrow hardenability band has small deformation after heat treatment, small gear grinding amount and high occlusion accuracy.The narrower the width of the hardenability belt, the smaller the dispersion, the more conducive to the processing of gears and the improvement of their occlusal accuracy.
The hardenability requirements for 19CN5 steel are as follows
Why does 19CN5 steel have grain size requirements?
The austenite grains are too coarse, which will increase the deformation cracking tendency of the steel and reduce the toughness. The fine and uniform austenite grains are of great significance to stabilize the end hardenability of the steel, reduce the deformation of the gear after heat treatment, and improve the brittle fracture resistance of the carburized steel.
For 19CN5 Steel,grain size requirements are generally 5-8, preferably 7-8.
What are the non-metallic inclusion requirements for 19CN5 steel?
Non-metallic inclusions not only affect the purity of 19CN5 steel, but also further affect its properties, such as reducing ductility and toughness.
For 19CN5 Gear steel, the non-metallic inclusions must meet the following requirements
|Max 2.0||Max 2.0||Max 2.0||Max 2.0||Max 2.0||Max 1.5||Max 2.0||Max 1.5|
What are the band structure requirements of 19CN5 steel?
If the structure uniformity of 19CN5 is poor and there is a serious band structure, it will lead to unsatisfactory structure and uneven hardness after carburizing or carbonitriding heat treatment.
For 19CN5 steel,the band structure must be below 2.0 level.
19CN5 STEEL HEAT TREATMENT
Temperature Selection for Different Types of Heat treatment for 19CN5
- Soft Annealing:650 – 700°C,Cooling in furnace,hardness below 197HBW.
- Tempering:180-200°C,air cooling
19CN5 Steel Mechanical Property
- Tensile strength：1185-1320Mpa
- Yield strength:960-970Mpa
WHAT WE SUPPLY FOR 19CN5 STEEL
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|