20Cr2Ni4A Alloy Steel Bar

20Cr2Ni4A Is a high-quality alloy steel, high strength, good toughness and hardenability. Not directly after carburizing quenching, in order to reduce the surface residual austenite. Machinability and cold plastic deformation in general. Poor welding, preheating before welding to about 150 ℃, the strong sensitivity of the white point of working hours, there is a tendency to temper brittleness. Carburizing parts for large cross-section, such as high-large gears, shafts and require strength, toughness, good tempered parts.

20Cr2Ni4A chemical composition %:

20Cr2Ni4A purposes:

For the manufacture of small and medium sized cars, tractor engine and transmission in gear, manufacture of high performance core part of carburized parts, cyanide parts, such as oil drilling and metallurgical open pit with claws and teeth cone body.

Mechanical Properties:

Tensile strength σb (MPa): 1483

Conditions yield strength σ0.2 (MPa): 1292

Elongation δ5 (%): 13

Reduction of ψ (%): 57

Impact toughness αkv (J / cm2): 75

Hardness: 434HB

Sample size: a sample

Heat treatment and microstructure specifications:

Heat treatment specifications: 880 ℃ oil quenching + 780 ℃ oil quenching, 200 ℃ tempering.

Machinability

Long, gummy chips characterize this alloys machinability. It can be machined in the annealed condition, however, condition H1150M will yield the best results. Post machining solution treatment of parts will be required prior to final hardening if machining in this condition.

Heat Treatment

CONDITION A–Soak at 1900 F (1038 C) for 30 minutes and cool below 60 F (16 C) for complete martensite transformation. CONDITION H 950- Treat Condition A material at 900 F(482 C) for 1 hour, air cool. CONDITION H925, H1025, H1075, H1100, H1150- Soak solution treated material for 4 hours at a specified temperature, air cool, CONDITION H1150M- Soak solution treated material at 1400 F (760 C) for 2 hours, air cool, then re-heat to 1150 F (620 C) for 4 hours and air cool.

Welding

Successfully welded by common fusion and resistance methods, this alloy should not be joined by oxyacetylene welding. AWS E/ER630 filler metal is recommended if required.

Forging

Soak for 1 hour at 2150 F (1177 C) prior to forging. Do not work below 1850 F (1010 C). Post-work solution treatment is required prior to final hardening.