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E: enquiry@qilumetal.com
E: enquiry@qilumetal.com
No. 18 Xiangfu Middle Road,Yuhua District, Changsha City
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Grade: GB 20CrNi3
20CrNi3 is a nickel-chromium alloy steel containing 0.17%–0.24% C, 0.60%–0.90% Cr for improved hardenability and surface hardening response, and 2.75%–3.15% Ni to significantly boost core toughness and fatigue resistance. Mn and Si are added to optimize strength-ductility balance, while P and S are strictly limited to ensure cleanliness.
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20CrNi3
Qilu
20CrNi3 steel is a classic chromium-nickel alloy structural steel specified under Chinese standard GB/T 3077-2015, categorized as carburizing & quenching-tempering dual-purpose steel grade. It contains balanced Cr and Ni alloy elements to greatly improve hardenability, delivering premium combination of high tensile strength and outstanding low-temperature impact toughness after standard heat treatment.
Different from common low-alloy steel, 20CrNi3 achieves dual performance: hard wear-resistant surface via carburizing treatment, while retaining tough inner core to resist heavy impact and alternating load. Its oil quenching penetration depth reaches Φ50–70mm, suitable for manufacturing medium & large cross-section heavy-duty mechanical components. The material features smooth machinability with moderate weldability, widely adopted in machinery, automotive, engineering equipment and transmission system manufacturing.
Grade | C | Si | Mn | P | S | Cr | Ni |
20CrNi3 | 0.17-0.24 | 0.17-0.37 | 0.30-0.60 | 0.030Max | 0.030Max | 0.60-0.90 | 2.75-3.15 |
| Property | Value (Min) |
| Tensile Strength | 930 MPa |
| Yield Strength | 735 MPa |
| Elongation at Break | 11% |
| Reduction of Area | 55% |
| Impact Toughness | 78 J |
| Hardness | 241Max HBW |
Full annealing at 650–680°C for stress relief, uniform internal grain structure, convenient secondary machining.
Heating temperature: 830°C; Cooling medium: water or oil.
Heating temperature: 480°C; Cooling medium: water or oil.
Product type | Size range | Length |
Cold drawn bar | Φ3-Φ80mm | 6000-9000mm |
Hot rolled bar | Φ16-Φ310mm | 6000-9000mm |
Hot forged bar | Φ100-Φ1200mm | 3000-5800mm |
Hot rolled plate/sheet | T:3-200mm; W:1500-2500mm | 2000-5800mm |
Hot Forged block | T: 80-800mm; W: 100-2500mm | 2000-5800mm |
Surface Finish | Turned | Milled | Grinding(Best) | Polished(Best) | Peeled(Best) | Black Forged | Black Rolled |
Tolerance | +0/+3mm | +0/+3mm | +0/+0.05mm | +0/+0.05mm | +0/+0.1mm | +0/+5mm | +0/+1mm |
Straighness | 1mm/1000mm max. | 3mm/1000mm max. | |||||
20CrNi3 alloy steel is specially designed for components operating under heavy load, alternating impact and low-temperature working conditions, typical application scenarios:
Heavy machinery transmission parts: Large gears, worms, machine tool spindles, cams, reducer shafts.
High-strength fasteners: Double end studs, locating pins, heavy-duty bolts, piston pins.
Automotive & engineering equipment core components: Drive shafts, clutch parts, hydraulic pump structural pieces.
General heavy load structural forgings for metallurgy, mining and marine machinery
20CrNi3: Higher nickel, deeper hardenability (up to Φ70mm), excellent low-temperature impact toughness, for large heavy-load gears in cold environments
20CrMnTi: Lower cost, limited hardening depth (≤Φ40mm), poor low-temperature toughness, for mass small auto gears at room temperature
20CrNi3: Low-carbon carburizing steel, hard wear-resistant surface + tough core, fit friction heavy-impact parts
40Cr: Medium-carbon quenched-tempered steel, uniform hardness, no carburizing needed, for general medium-strength shafts
20CrNi3: Carburizable, superior cryogenic toughness, for low-temp large transmission components
42CrMo: Cr-Mo tempered steel, stable high-temperature strength, no hard surface layer, for hot-working heavy shafts
20CrNi3: Higher nickel, deeper hardenability, better sub-zero toughness, stricter forging control to avoid white spots
20CrNi2Mo: Lower nickel with molybdenum, fewer internal defects, ideal for medium-size carburizing gears
20CrMnTi: Small room-temperature auto gears
40Cr: Ordinary medium-strength shafts
42CrMo: High-temperature heavy shafts
20CrNi2Mo: Medium stable carburizing gears
20CrNi3: Large-section, low-temp heavy impact wear parts
A1: 20CrNi3 contains higher nickel content, better low-temperature toughness and deeper hardenability, suitable for large cross-section heavy-load gears and shafts; 20CrMnTi is more cost-effective for small-medium size automobile gears.
A2: Yes, 20CrNi3 is a mainstream carburizing alloy steel. After carburizing quenching, the surface achieves high hardness for wear resistance while the core maintains high toughness to resist impact load.
A3: Under standard 830°C oil quenching process, full hardening depth reaches Φ50–70mm; thicker workpieces adopt water quenching for better through-hardening effect.
A4: Annealed delivery hardness ≤241HBW, soft enough for direct CNC turning and drilling without pre-annealing treatment.
Contact us with your required size, quantity, and heat treatment specifications. We will reply with a detailed quotation, technical data sheet, and available stock status within 24 hours.
