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E: enquiry@qilumetal.com
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20MnCr5 / 1.7147 is an alloyed carburized steel belonging to the European standards EN 10084 and EN 10250-3. It is widely used in several industries, such as automotive manufacturing, heavy machinery and highly loaded transmission components. You can find equivalents in different national standards, such as American Standard ASTM 5120 (ASTM A29/A29M) and Chinese Standard 20CrMn (GB/T 3077).
20MnCr5 is part of the Mn-Cr steel series, with a carbon content ranging from 0.17-0.22%. This steel is particularly valued for its ability to achieve a balance between surface hardness and core toughness after undergoing carburizing and heat treatment processes. Its excellent wear resistance and fatigue strength make it a preferred choice for components subjected to high stress and friction. Commonly used in the production of gears, shafts, and other transmission parts, 20MnCr5 is ideal for applications where durability and reliability are critical.
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DIN 20MnCr5 1.7147 and ASTM 5120 are low-carbon alloyed carburized steels engineered to deliver a critical balance of surface hardness and core toughness, a combination that makes them indispensable in industries where components face repeated stress, friction, and heavy loads.
DIN 20MnCr5 1.7147 adheres to European standards EN 10084 and EN 10250-3, while ASTM 5120 complies with ASTM A29/A29M (American Society for Testing and Materials). For Asian markets, both grades are equivalent to China’s GB/T 3077 20CrMn, simplifying cross-regional sourcing for multinational manufacturers.
At the heart of their performance lies a carefully calibrated chemical composition: DIN 20MnCr5 1.7147 features a carbon content of 0.17-0.22%, paired with 1.10-1.40% manganese and 1.0-1.3% chromium, while ASTM 5120 has a slightly lower manganese range (0.70-0.90%) and chromium range (0.7-0.9%). This composition ensures the steel responds exceptionally well to carburization—creating a hard, wear-resistant surface (up to 60HRC) while keeping the core ductile enough to avoid brittle failure.
Beyond their material properties, these steels are supplied in versatile forms (hot-rolled bars, forged bars, forged blocks) to accommodate diverse production needs, from small precision gears to large industrial shafts. Their consistent quality and global standard equivalence have made them a go-to choice for engineers seeking reliability in safety-critical and high-demand applications.
The performance of DIN 20MnCr5 1.7147 and ASTM 5120 is rooted in their optimized chemical makeup, which balances alloy elements to enhance key properties without compromising usability.
Grade | Carbon (C) | Manganese (Mn) | Chromium (Cr) | Phosphorus (P) Max | Sulfur (S) Max |
ASTM 5120 | 0.17-0.22 | 0.70-0.90 | 0.7-0.9 | 0.035% | 0.040% |
DIN 20MnCr5 1.7147 | 0.17-0.22 | 1.10-1.40 | 1.0-1.3 | 0.025% | 0.035% |
Low carbon content (0.17-0.22%): Prevents core brittleness during carburization, ensuring components can absorb impact without cracking.
Manganese variation: Higher manganese in DIN 20MnCr5 1.7147 (1.10-1.40%) boosts hardenability, allowing deeper hardness penetration for thicker components, while ASTM 5120’s lower range suits smaller parts where rapid cooling is easier.
Controlled impurities: Strict limits on phosphorus (≤0.025% for DIN 20MnCr5 1.7147) and sulfur (≤0.035% for both grades) reduce microcrack risk, enhancing overall material integrity.
After proper heat treatment, both steels exhibit consistent mechanical properties that meet the demands of high-stress applications.
Diameters ≤16mm: Tensile strength ≥ 1200MPa (ideal for small gears and fasteners).
Diameters 16mm < d ≤40mm: Tensile strength ≥ 800MPa (suited for medium-sized shafts).
Diameters 40mm < d ≤100mm: Tensile strength ≥ 600MPa (reliable for large industrial components).
For a 16mm test bar, the steel delivers:
Elongation ≥ 8% (ensures flexibility under load).
Impact value at room temperature ≥ 20J (resists sudden shock, critical for automotive drivetrain parts).
These properties make DIN 20MnCr5 1.7147 and ASTM 5120 stand out from common carbon steels, which often lack the fatigue strength needed for long-term use in cyclic-load applications.
Both grades respond flexibly to heat treatment, allowing manufacturers to tailor performance to specific component needs:
Soft Annealing: Heat to 650-700℃, furnace cool. Results in hardness ≤ 217HB, making the steel easy to machine (e.g., for gear cutting).
Normalization: Heat to 840-870℃, air cool. Creates a uniform ferrite-pearlite structure with hardness 140-201HB, ideal for prepping parts for further processing.
Carburization: Heat DIN 20MnCr5 1.7147 to 880-980℃ (adjust time for case depth) to achieve a surface hardness of 58-62HRC—perfect for wear-prone parts like gear teeth.
Quenching & Tempering: Heat to 830-840℃, quench in oil (for minimal distortion), then temper at 150-200℃. Reduces residual stress while preserving surface hardness, extending component lifespan.
Hunan Qilu Steel offers DIN 20MnCr5 1.7147 and ASTM 5120 in a range of sizes and finishes to match diverse production workflows:
Hot-Rolled Bars: Diameters Φ14-280mm, length 6000-9000mm, tolerance +0/+1mm (cost-effective for rough machining).
Hot-Forged Bars: Diameters Φ140-1200mm, length 3000-5800mm, tolerance +0/+5mm (for large, heavy-duty parts like excavator shafts).
Hot-Forged Blocks: Thickness 80-800mm, width 100-2500mm, length 2000-5800mm (customizable for complex components).
Finishes include black rolled (for industrial use), peeled (for improved surface smoothness), and ground (tolerance +0/+0.05mm) for precision applications like aerospace parts.
The automotive industry relies heavily on DIN 20MnCr5 1.7147 and ASTM 5120 for components that endure high torque and frequent use:
Transmission Gears: Manual and automatic transmission gears benefit from the steel’s high fatigue strength (≥20J impact value) and wear resistance (up to 62HRC post-carburization), preventing tooth wear even after 100,000+ kilometers of driving.
Drive Shafts: Half-shafts and propeller shafts use the steel’s tensile strength (≥800MPa for d≤40mm) to withstand torsion forces, ensuring power transfers smoothly from engine to wheels.
Clutch Components: Clutch pressure plates and flywheels leverage the steel’s ductility (≥8% elongation) to handle repeated engagement without warping.
In industrial settings, these steels power critical transmission and fastening systems:
Sprockets & Pulleys: Conveyor sprockets and pulley shafts use DIN 20MnCr5 1.7147’s hardness (170-217HBW in +TH grade) to resist abrasive wear from chains and belts, reducing maintenance downtime.
High-Strength Fasteners: Bolts and nuts for turbines and compressors rely on the steel’s yield strength (≥540MPa for d=63mm) to stay secure under vibration, avoiding costly equipment failures.
Construction machinery operates in harsh, dusty environments, and DIN 20MnCr5 1.7147 delivers the durability needed:
Excavator Gears: Swing gears and travel gears use the steel’s impact resistance (≥23J for d=63mm) to withstand collisions with rocks and debris, while its hardenability ensures uniform performance across thick sections.
Loader Hydraulic Shafts: Hydraulic loader shafts depend on the steel’s toughness to handle sudden load changes (e.g., lifting 10+ ton materials) without bending or cracking.
While not used in primary flight structures, ASTM 5120 finds application in aerospace auxiliary systems:
APU Transmission Parts: Auxiliary Power Unit (APU) gears use the steel’s high-temperature stability (up to 200℃ in tempered condition) to operate reliably in engine bays.
Landing Gear Linkages: Small landing gear linkages benefit from the steel’s precision (ground finish tolerance +0/+0.05mm) and strength, ensuring smooth landing operations.
The key difference lies in hardenability and impurity limits, which guide application choice:
Hardenability: DIN 20MnCr5 1.7147’s higher manganese (1.10-1.40%) allows deeper hardness penetration, making it better for thick components (e.g., d>40mm shafts). ASTM 5120’s lower manganese (0.70-0.90%) suits smaller parts (e.g., d≤16mm gears) where rapid cooling achieves sufficient hardness.
Impurities: DIN 20MnCr5 1.7147 has stricter phosphorus limits (≤0.025% vs. 0.035% for ASTM 5120), making it preferable for safety-critical parts (e.g., automotive brakes). For non-critical components (e.g., industrial brackets), ASTM 5120 offers cost savings without compromising performance.
Both steels have limited weldability due to manganese and chromium, but successful welding is possible with proper steps:
Preheat: Warm the steel to 150-250℃ to reduce heat-affected zone (HAZ) cracking—critical, as chromium can form hard microstructures in the HAZ.
Electrode Choice: Use low-hydrogen electrodes (e.g., E7018) to minimize hydrogen-induced cracking, a common issue with alloy steels.
Post-Weld Heat Treatment: Temper at 150-200℃ to relieve residual stress and restore toughness.
Note: Avoid welding carburized parts, as heat will soften the hard surface layer—weld only in annealed or normalized states.
Hunan Qilu Steel maintains monthly stocks of 10,000+ tons of DIN 20MnCr5 1.7147 and ASTM 5120, with common hot-rolled bar diameters including 14mm, 16mm, 20mm, 25mm, 30mm, 40mm, 50mm, 80mm, 100mm, 150mm, and 200mm. Stock levels change daily, so contact our sales team via WhatsApp (+86-15084978853) or email (enquiry@qilumetal.com) for real-time availability, including custom finishes (e.g., polished, ground).
For gears, the optimal process is carburization + oil quenching + low-temperature tempering:
Carburization: Heat to 920-950℃ for 4-8 hours (adjust time for desired case depth—typically 0.8-1.5mm for gear teeth) to diffuse carbon into the surface.
Quenching: Cool rapidly in oil (slower than water, reducing distortion) to harden the surface to 58-62HRC.
Tempering: Heat to 180-200℃ for 2 hours to reduce brittleness while preserving surface hardness.
This process ensures gear teeth resist wear (hard surface) and absorb impact (tough core), extending gear life by 30-50% compared to uncarburized steels.
DIN 20MnCr5 1.7147 and ASTM 5120 outperform generic alloys in three key ways:
Global Standard Compliance: Compliance with EN 10084, ASTM A29, and GB/T 3077 eliminates certification barriers for international sales.
Consistent Performance: Tight chemical and mechanical tolerances (e.g., carbon ±0.02%, tensile strength ±50MPa) ensure every batch performs the same, reducing production defects.
Total Cost Savings: While upfront costs are 10-15% higher than generic steels, their longer lifespan (2-3x vs. common carbon steels) and lower maintenance needs cut total ownership costs by 20-25% over 5 years.
1: Steel equivalent
Country | USA | Europe | China |
Standard | ASTM A29 | EN10084 | GB/T3077 |
Grade | 5120 | 20MnCr5/1.7147 | 20CrMn |
2: Chemical composition
Grade | C | Si | Mn | P | S | Cr |
5120 | 0.17-0.22 | 0.15-0.35 | 0.70-0.90 | 0.035Max | 0.040Max | 0.7-0.9 |
20MnCr5/1.7147 | 0.17-0.22 | 0.40Max | 1.10-1.40 | 0.025Max | 0.035Max | 1.0-1.3 |
20CrMn | 0.17-0.23 | 0.17-0.37 | 0.90-1.20 | 0.030Max | 0.030Max | 0.9-1.2 |
3: Mechanical properties .
Steel grades 20MnCr5 according to minimum tensile strength as a function of diameter after hardening and tempering at 200℃ according to EN10084.
Size range | Tensile strength |
d≤16 | 1200Mpa Min |
16＜d≤40 | 800Mpa Min |
40＜d≤100 | 600Mpa Min |
Mechanical properties for reference test bar in the simulated case-hardening condition according to ISO 683-11-1987.
Size range | Tensile strength | Yield strength | Alongation | Impact value At RT/J |
d=16 | 1000-1350Mpa | 670Mpa Min | 8% Min | 20J Min |
d=30 | 900-1250Mpa | 610Mpa Min | 9% Min | 20J Min |
d=63 | 780-1130Mpa | 540Mpa Min | 10% Min | 23J Min |
Sampling and preparation of test pieces for 20MnCr5 case-hardening steel.
1): According to EN10084, all samples shall be taken at a distance of 1/4 of the diameter or thickness below the heat-treated surface.
2): As stipulated in the contract between buyer and seller.
4: Surface hardness and hardenability.
Heat Treatment | Hardness |
Treated to improve shearability (+S) | HB255Max |
Soft annealed (+A) | HB217Max |
Treated to hardness range(+TH) | 170-217HBW |
Treated to ferrite-pearlite structure and hardness range(+FP) | 152-201HBW |
Normalized(+N) | 140-201HBW |
Where the steel is ordered by using the symbols for normal (+H) or restricted (+HL, +HH) hardenability requirements, the hardenability values should apply below:
Distance in mm from quenched end | ||||||||||||||
Distance | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 | |
Hardness In HRC + H | max | 49 | 49 | 48 | 46 | 43 | 42 | 41 | 39 | 37 | 35 | 34 | 33 | 32 |
min | 41 | 39 | 36 | 33 | 30 | 28 | 26 | 25 | 23 | 21 | / | / | / | |
Hardness In HRC + HH | max | 49 | 49 | 48 | 46 | 43 | 42 | 41 | 39 | 37 | 35 | 34 | 33 | 32 |
min | 44 | 42 | 40 | 37 | 34 | 33 | 31 | 30 | 28 | 26 | 25 | 24 | 23 | |
Hardness In HRC + HL | max | 46 | 46 | 44 | 42 | 39 | 37 | 36 | 34 | 32 | 30 | 29 | 28 | 27 |
min | 41 | 39 | 36 | 33 | 30 | 28 | 26 | 25 | 23 | 21 | / | / | / | |
Scatter bands for the Rockwell - C hardness in the end quench hardenability test.
Key
X distance from quenched end of test piece, mm
Y hardness, HRC
1 upper limit
2 upper limit, +HL grades
3 lower limit, +HH grades
4 lower limit
5: Supply size & Tolerance & Stock size
Product type | Size range | Length |
Hot rolled bar | Φ14-Φ280mm | 6000-9000mm |
Hot forged bar | Φ140-Φ1200mm | 3000-5800mm |
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. | |||||
Qilu steel stock hot rolled bar and forged bars more than ten thousands tons every month, below our our stock size.
1): Stock diameter for hot rolled bar
14 | 16 | 18 | 20 | 22 | 25 | 28 | 30 | 32 | 35 | 38 | 40 | 42 | 45 | 50 |
55 | 60 | 65 | 70 | 75 | 80 | 85 | 90 | 95 | 100 | 105 | 110 | 115 | 120 | 130 |
140 | 150 | 160 | 170 | 180 | 190 | 200 | 210 | 220 | 230 | 240 | 250 | 260 | 270 | 280 |
DIN 20MnCr5 1.7147 and ASTM 5120 are low-carbon alloyed carburized steels engineered to deliver a critical balance of surface hardness and core toughness, a combination that makes them indispensable in industries where components face repeated stress, friction, and heavy loads.
DIN 20MnCr5 1.7147 adheres to European standards EN 10084 and EN 10250-3, while ASTM 5120 complies with ASTM A29/A29M (American Society for Testing and Materials). For Asian markets, both grades are equivalent to China’s GB/T 3077 20CrMn, simplifying cross-regional sourcing for multinational manufacturers.
At the heart of their performance lies a carefully calibrated chemical composition: DIN 20MnCr5 1.7147 features a carbon content of 0.17-0.22%, paired with 1.10-1.40% manganese and 1.0-1.3% chromium, while ASTM 5120 has a slightly lower manganese range (0.70-0.90%) and chromium range (0.7-0.9%). This composition ensures the steel responds exceptionally well to carburization—creating a hard, wear-resistant surface (up to 60HRC) while keeping the core ductile enough to avoid brittle failure.
Beyond their material properties, these steels are supplied in versatile forms (hot-rolled bars, forged bars, forged blocks) to accommodate diverse production needs, from small precision gears to large industrial shafts. Their consistent quality and global standard equivalence have made them a go-to choice for engineers seeking reliability in safety-critical and high-demand applications.
The performance of DIN 20MnCr5 1.7147 and ASTM 5120 is rooted in their optimized chemical makeup, which balances alloy elements to enhance key properties without compromising usability.
Grade | Carbon (C) | Manganese (Mn) | Chromium (Cr) | Phosphorus (P) Max | Sulfur (S) Max |
ASTM 5120 | 0.17-0.22 | 0.70-0.90 | 0.7-0.9 | 0.035% | 0.040% |
DIN 20MnCr5 1.7147 | 0.17-0.22 | 1.10-1.40 | 1.0-1.3 | 0.025% | 0.035% |
Low carbon content (0.17-0.22%): Prevents core brittleness during carburization, ensuring components can absorb impact without cracking.
Manganese variation: Higher manganese in DIN 20MnCr5 1.7147 (1.10-1.40%) boosts hardenability, allowing deeper hardness penetration for thicker components, while ASTM 5120’s lower range suits smaller parts where rapid cooling is easier.
Controlled impurities: Strict limits on phosphorus (≤0.025% for DIN 20MnCr5 1.7147) and sulfur (≤0.035% for both grades) reduce microcrack risk, enhancing overall material integrity.
After proper heat treatment, both steels exhibit consistent mechanical properties that meet the demands of high-stress applications.
Diameters ≤16mm: Tensile strength ≥ 1200MPa (ideal for small gears and fasteners).
Diameters 16mm < d ≤40mm: Tensile strength ≥ 800MPa (suited for medium-sized shafts).
Diameters 40mm < d ≤100mm: Tensile strength ≥ 600MPa (reliable for large industrial components).
For a 16mm test bar, the steel delivers:
Elongation ≥ 8% (ensures flexibility under load).
Impact value at room temperature ≥ 20J (resists sudden shock, critical for automotive drivetrain parts).
These properties make DIN 20MnCr5 1.7147 and ASTM 5120 stand out from common carbon steels, which often lack the fatigue strength needed for long-term use in cyclic-load applications.
Both grades respond flexibly to heat treatment, allowing manufacturers to tailor performance to specific component needs:
Soft Annealing: Heat to 650-700℃, furnace cool. Results in hardness ≤ 217HB, making the steel easy to machine (e.g., for gear cutting).
Normalization: Heat to 840-870℃, air cool. Creates a uniform ferrite-pearlite structure with hardness 140-201HB, ideal for prepping parts for further processing.
Carburization: Heat DIN 20MnCr5 1.7147 to 880-980℃ (adjust time for case depth) to achieve a surface hardness of 58-62HRC—perfect for wear-prone parts like gear teeth.
Quenching & Tempering: Heat to 830-840℃, quench in oil (for minimal distortion), then temper at 150-200℃. Reduces residual stress while preserving surface hardness, extending component lifespan.
Hunan Qilu Steel offers DIN 20MnCr5 1.7147 and ASTM 5120 in a range of sizes and finishes to match diverse production workflows:
Hot-Rolled Bars: Diameters Φ14-280mm, length 6000-9000mm, tolerance +0/+1mm (cost-effective for rough machining).
Hot-Forged Bars: Diameters Φ140-1200mm, length 3000-5800mm, tolerance +0/+5mm (for large, heavy-duty parts like excavator shafts).
Hot-Forged Blocks: Thickness 80-800mm, width 100-2500mm, length 2000-5800mm (customizable for complex components).
Finishes include black rolled (for industrial use), peeled (for improved surface smoothness), and ground (tolerance +0/+0.05mm) for precision applications like aerospace parts.
The automotive industry relies heavily on DIN 20MnCr5 1.7147 and ASTM 5120 for components that endure high torque and frequent use:
Transmission Gears: Manual and automatic transmission gears benefit from the steel’s high fatigue strength (≥20J impact value) and wear resistance (up to 62HRC post-carburization), preventing tooth wear even after 100,000+ kilometers of driving.
Drive Shafts: Half-shafts and propeller shafts use the steel’s tensile strength (≥800MPa for d≤40mm) to withstand torsion forces, ensuring power transfers smoothly from engine to wheels.
Clutch Components: Clutch pressure plates and flywheels leverage the steel’s ductility (≥8% elongation) to handle repeated engagement without warping.
In industrial settings, these steels power critical transmission and fastening systems:
Sprockets & Pulleys: Conveyor sprockets and pulley shafts use DIN 20MnCr5 1.7147’s hardness (170-217HBW in +TH grade) to resist abrasive wear from chains and belts, reducing maintenance downtime.
High-Strength Fasteners: Bolts and nuts for turbines and compressors rely on the steel’s yield strength (≥540MPa for d=63mm) to stay secure under vibration, avoiding costly equipment failures.
Construction machinery operates in harsh, dusty environments, and DIN 20MnCr5 1.7147 delivers the durability needed:
Excavator Gears: Swing gears and travel gears use the steel’s impact resistance (≥23J for d=63mm) to withstand collisions with rocks and debris, while its hardenability ensures uniform performance across thick sections.
Loader Hydraulic Shafts: Hydraulic loader shafts depend on the steel’s toughness to handle sudden load changes (e.g., lifting 10+ ton materials) without bending or cracking.
While not used in primary flight structures, ASTM 5120 finds application in aerospace auxiliary systems:
APU Transmission Parts: Auxiliary Power Unit (APU) gears use the steel’s high-temperature stability (up to 200℃ in tempered condition) to operate reliably in engine bays.
Landing Gear Linkages: Small landing gear linkages benefit from the steel’s precision (ground finish tolerance +0/+0.05mm) and strength, ensuring smooth landing operations.
The key difference lies in hardenability and impurity limits, which guide application choice:
Hardenability: DIN 20MnCr5 1.7147’s higher manganese (1.10-1.40%) allows deeper hardness penetration, making it better for thick components (e.g., d>40mm shafts). ASTM 5120’s lower manganese (0.70-0.90%) suits smaller parts (e.g., d≤16mm gears) where rapid cooling achieves sufficient hardness.
Impurities: DIN 20MnCr5 1.7147 has stricter phosphorus limits (≤0.025% vs. 0.035% for ASTM 5120), making it preferable for safety-critical parts (e.g., automotive brakes). For non-critical components (e.g., industrial brackets), ASTM 5120 offers cost savings without compromising performance.
Both steels have limited weldability due to manganese and chromium, but successful welding is possible with proper steps:
Preheat: Warm the steel to 150-250℃ to reduce heat-affected zone (HAZ) cracking—critical, as chromium can form hard microstructures in the HAZ.
Electrode Choice: Use low-hydrogen electrodes (e.g., E7018) to minimize hydrogen-induced cracking, a common issue with alloy steels.
Post-Weld Heat Treatment: Temper at 150-200℃ to relieve residual stress and restore toughness.
Note: Avoid welding carburized parts, as heat will soften the hard surface layer—weld only in annealed or normalized states.
Hunan Qilu Steel maintains monthly stocks of 10,000+ tons of DIN 20MnCr5 1.7147 and ASTM 5120, with common hot-rolled bar diameters including 14mm, 16mm, 20mm, 25mm, 30mm, 40mm, 50mm, 80mm, 100mm, 150mm, and 200mm. Stock levels change daily, so contact our sales team via WhatsApp (+86-15084978853) or email (enquiry@qilumetal.com) for real-time availability, including custom finishes (e.g., polished, ground).
For gears, the optimal process is carburization + oil quenching + low-temperature tempering:
Carburization: Heat to 920-950℃ for 4-8 hours (adjust time for desired case depth—typically 0.8-1.5mm for gear teeth) to diffuse carbon into the surface.
Quenching: Cool rapidly in oil (slower than water, reducing distortion) to harden the surface to 58-62HRC.
Tempering: Heat to 180-200℃ for 2 hours to reduce brittleness while preserving surface hardness.
This process ensures gear teeth resist wear (hard surface) and absorb impact (tough core), extending gear life by 30-50% compared to uncarburized steels.
DIN 20MnCr5 1.7147 and ASTM 5120 outperform generic alloys in three key ways:
Global Standard Compliance: Compliance with EN 10084, ASTM A29, and GB/T 3077 eliminates certification barriers for international sales.
Consistent Performance: Tight chemical and mechanical tolerances (e.g., carbon ±0.02%, tensile strength ±50MPa) ensure every batch performs the same, reducing production defects.
Total Cost Savings: While upfront costs are 10-15% higher than generic steels, their longer lifespan (2-3x vs. common carbon steels) and lower maintenance needs cut total ownership costs by 20-25% over 5 years.
1: Steel equivalent
Country | USA | Europe | China |
Standard | ASTM A29 | EN10084 | GB/T3077 |
Grade | 5120 | 20MnCr5/1.7147 | 20CrMn |
2: Chemical composition
Grade | C | Si | Mn | P | S | Cr |
5120 | 0.17-0.22 | 0.15-0.35 | 0.70-0.90 | 0.035Max | 0.040Max | 0.7-0.9 |
20MnCr5/1.7147 | 0.17-0.22 | 0.40Max | 1.10-1.40 | 0.025Max | 0.035Max | 1.0-1.3 |
20CrMn | 0.17-0.23 | 0.17-0.37 | 0.90-1.20 | 0.030Max | 0.030Max | 0.9-1.2 |
3: Mechanical properties .
Steel grades 20MnCr5 according to minimum tensile strength as a function of diameter after hardening and tempering at 200℃ according to EN10084.
Size range | Tensile strength |
d≤16 | 1200Mpa Min |
16＜d≤40 | 800Mpa Min |
40＜d≤100 | 600Mpa Min |
Mechanical properties for reference test bar in the simulated case-hardening condition according to ISO 683-11-1987.
Size range | Tensile strength | Yield strength | Alongation | Impact value At RT/J |
d=16 | 1000-1350Mpa | 670Mpa Min | 8% Min | 20J Min |
d=30 | 900-1250Mpa | 610Mpa Min | 9% Min | 20J Min |
d=63 | 780-1130Mpa | 540Mpa Min | 10% Min | 23J Min |
Sampling and preparation of test pieces for 20MnCr5 case-hardening steel.
1): According to EN10084, all samples shall be taken at a distance of 1/4 of the diameter or thickness below the heat-treated surface.
2): As stipulated in the contract between buyer and seller.
4: Surface hardness and hardenability.
Heat Treatment | Hardness |
Treated to improve shearability (+S) | HB255Max |
Soft annealed (+A) | HB217Max |
Treated to hardness range(+TH) | 170-217HBW |
Treated to ferrite-pearlite structure and hardness range(+FP) | 152-201HBW |
Normalized(+N) | 140-201HBW |
Where the steel is ordered by using the symbols for normal (+H) or restricted (+HL, +HH) hardenability requirements, the hardenability values should apply below:
Distance in mm from quenched end | ||||||||||||||
Distance | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 | |
Hardness In HRC + H | max | 49 | 49 | 48 | 46 | 43 | 42 | 41 | 39 | 37 | 35 | 34 | 33 | 32 |
min | 41 | 39 | 36 | 33 | 30 | 28 | 26 | 25 | 23 | 21 | / | / | / | |
Hardness In HRC + HH | max | 49 | 49 | 48 | 46 | 43 | 42 | 41 | 39 | 37 | 35 | 34 | 33 | 32 |
min | 44 | 42 | 40 | 37 | 34 | 33 | 31 | 30 | 28 | 26 | 25 | 24 | 23 | |
Hardness In HRC + HL | max | 46 | 46 | 44 | 42 | 39 | 37 | 36 | 34 | 32 | 30 | 29 | 28 | 27 |
min | 41 | 39 | 36 | 33 | 30 | 28 | 26 | 25 | 23 | 21 | / | / | / | |
Scatter bands for the Rockwell - C hardness in the end quench hardenability test.
Key
X distance from quenched end of test piece, mm
Y hardness, HRC
1 upper limit
2 upper limit, +HL grades
3 lower limit, +HH grades
4 lower limit
5: Supply size & Tolerance & Stock size
Product type | Size range | Length |
Hot rolled bar | Φ14-Φ280mm | 6000-9000mm |
Hot forged bar | Φ140-Φ1200mm | 3000-5800mm |
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. | |||||
Qilu steel stock hot rolled bar and forged bars more than ten thousands tons every month, below our our stock size.
1): Stock diameter for hot rolled bar
14 | 16 | 18 | 20 | 22 | 25 | 28 | 30 | 32 | 35 | 38 | 40 | 42 | 45 | 50 |
55 | 60 | 65 | 70 | 75 | 80 | 85 | 90 | 95 | 100 | 105 | 110 | 115 | 120 | 130 |
140 | 150 | 160 | 170 | 180 | 190 | 200 | 210 | 220 | 230 | 240 | 250 | 260 | 270 | 280 |
