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Heat Treated 40CrNiMoA Alloy Steel Round Bar with Polished Surface and OD 6-630mm
Product Details
| Model NO. | 40CrNiMoA | Surface Treatment | Polished |
|---|---|---|---|
| Alloy Type | Alloy | Special Use | Mold Steel |
| Transport Package | Wooden Box | Diameter Range | OD 6-630mm |
| Production Capacity | 500tons | Tensile Strength | 930-1080 Mpa |
| Yield Strength | 740 MPa | Elongation | 12% |
| Impact Resistance | 47 J | Brinell Hardness | 269-331 |
| Thermal Conductivity | 44.5 W/mK | Forging Temperature | 1150°C - 1200°C |
| Annealing Temperature | 844°C | ||
| Highlight | Heat Treated Alloy Steel Round Bar,Polished Surface 40CrNiMoA Round Bar,OD 6-630mm Tool Steel Bar |
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Product Description
AISI 4340 Alloy Structural Steel
AISI 4340 steel is a medium carbon, low alloy steel known for its toughness and strength in relatively large sections. This nickel chromium molybdenum steel is generally supplied hardened and tempered in the tensile range of 930-1080 MPa. Pre-hardened and tempered 4340 steels can be further surface hardened by flame or induction hardening and by nitriding.
Material Specifications and Standards
| Country | USA | Britain | Britain | Japan |
|---|---|---|---|---|
| Standard | ASTM A29 | EN 10250 | BS 970 | JIS G4103 |
| Grades | 4340 | 36CrNiMo4/1.6511 | EN24/817M40 | SNCM 439/SNCM8 |
Chemical Composition
| Standard | Grade | C | Mn | P | S | Si | Ni | Cr | Mo |
|---|---|---|---|---|---|---|---|---|---|
| ASTM A29 | 4340 | 0.38-0.43 | 0.60-0.80 | 0.035 | 0.040 | 0.15-0.35 | 1.65-2.00 | 0.70-0.90 | 0.20-0.30 |
| EN 10250 | 36CrNiMo4/1.6511 | 0.32-0.40 | 0.50-0.80 | 0.035 | 0.035 | ≤0.40 | 0.90-1.20 | 0.90-1.2 | 0.15-0.30 |
| BS 970 | EN24/817M40 | 0.36-0.44 | 0.45-0.70 | 0.035 | 0.040 | 0.1-0.40 | 1.3-1.7 | 1.00-1.40 | 0.20-0.35 |
| JIS G4103 | SNCM 439/SNCM8 | 0.36-0.43 | 0.60-0.90 | 0.030 | 0.030 | 0.15-0.35 | 1.60-2.00 | 0.60-1.00 | 0.15-0.30 |
Mechanical Properties
| Condition | Ruling Section (mm) | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Izod Impact (J) | Brinell Hardness |
|---|---|---|---|---|---|---|
| T | 250 | 850-1000 | 635 | 13 | 40 | 248-302 |
| T | 150 | 850-1000 | 665 | 13 | 54 | 248-302 |
| U | 100 | 930-1080 | 740 | 12 | 47 | 269-331 |
| V | 63 | 1000-1150 | 835 | 12 | 47 | 293-352 |
| W | 30 | 1080-1230 | 925 | 11 | 41 | 311-375 |
| X | 30 | 1150-1300 | 1005 | 10 | 34 | 341-401 |
| Y | 30 | 1230-1380 | 1080 | 10 | 24 | 363-429 |
| Z | 30 | 1555- | 1125 | 5 | 10 | 444- |
Thermal Properties
| Properties | Metric | Imperial |
|---|---|---|
| Thermal expansion coefficient (20°C/68°F) | 12.3 µm/m°C | 6.83 µin/in°F |
| Thermal conductivity | 44.5 W/mK | 309 BTU in/hr.ft².°F |
Forging Process
Preheat the steel to 1150°C - 1200°C maximum for forging, holding until temperature is uniform throughout the section. Do not forge below 850°C. Following forging operations, the workpiece should be cooled as slowly as possible in sand or dry lime to prevent cracking.
Heat Treatment Procedures
Stress Relieving
Heat to 600°C - 650°C, hold until uniform temperature, soak for 1 hour per 25mm section, and cool in still air.
Annealing
Full anneal at 844°C (1550°F) followed by controlled furnace cooling at ≤10°C (50°F) per hour down to 315°C (600°F), then air cool.
Tempering
Temper at 232°C (450°F) for 260-280 ksi strength or 510°C (950°F) for 125-200 ksi strength. Avoid tempering between 250°C-450°C due to temper brittleness.
Flame or Induction Hardening
Heat to 830°C-860°C austenitic range followed by immediate oil or water quenching. Temper at 150°C-200°C to reduce case stresses.
Nitriding
Heat to 500°C-530°C for 10-60 hours to develop case depth. Achieves surface hardness of 600-650HV with minimal core strength effect.
Machining and Welding
Machining is best performed in annealed or normalized and tempered conditions. Welding in hardened and tempered condition is not recommended. If necessary, preheat to 200-300°C and stress relieve at 550-650°C after welding.
Applications
- Aircraft Landing Gear
- Automotive Components
- Oil and Gas Drilling Equipment
- Power Transmission Gears and Shafts
- Heavy Duty Shafts, Axles, and Spindles
- Forging Dies and Molds
- General Engineering and Structural Components
Available Sizes and Conditions
Round bars: 12-380mm diameter. Available in various conditions including pre-hardened, hot rolled, annealed, quenched and tempered. Surface conditions include black, pre-machined, grinding, and polish.
Product Images
Quality Assurance and Services
Quality Commitment
ISO 9001 certified quality management system with regular audits and continuous improvement.
Timely Delivery
Speedy processing and delivery for both raw materials and finished components.
Value-Added Services
Metal cutting, sizing, machining (blanking, milling, grinding), and heat treatment services available.
Comprehensive Inventory
Unique inventory of specialty steels with orders of any size or length accommodated.
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