Project Description
AISI 4142 Steel Round Bar – Premium Oil & Gas Grade
🔧 Oil & Gas Grade Chrome-Molybdenum Alloy Steel
AISI 4142 is a premium chrome-molybdenum alloy steel specifically engineered for demanding oil and gas applications requiring superior hardenability, toughness, and fatigue resistance. This medium-carbon steel achieves exceptional mechanical properties through controlled quenching and tempering, making it the preferred choice for drill collars, tool joints, and wellhead equipment operating in severe environments.
Supply Conditions: Hot Rolled, Forged, Peeled & Rough Turned (optimized for ultrasonic testing), Quenched & Tempered (Q+T) to customer specifications.
Compliance: Fully compliant with API Spec 7-1 (drill collar applications), API 6A (wellhead equipment), and NACE MR0175 (sour service environments).
🔬 Critical Standards & Material Equivalents
| Standard | Designation | Country | Application Focus |
|---|---|---|---|
| AISI/SAE | 4142 | USA | Oil & Gas Equipment |
| ASTM | A322 Grade 4142 | USA | Alloy Steel Bars |
| DIN | 1.7225 (42CrMo4) | Germany | Quenched & Tempered Steel |
| JIS | SCM440 | Japan | Machine Structural Steel |
| API Spec 7-1 | Grade L80 Type 1 | USA | Drill Collar Applications |
Critical Compliance: AISI 4142 meets stringent API 6A material requirements for wellhead equipment and API Spec 7-1 for drill collar applications. The chromium-molybdenum content provides excellent hardenability while maintaining NACE MR0175 compliance for sour service environments with H₂S concentrations up to 0.05 psia partial pressure.
⚙️ Technical Specifications
Chemical Composition (Heat Analysis)
| Element | Min % | Max % | SHUNFU Control | Impact on Properties |
|---|---|---|---|---|
| Carbon (C) | 0.38 | 0.45 | 0.40-0.43 | Strength & hardenability |
| Manganese (Mn) | 0.60 | 1.00 | 0.75-0.90 | Deoxidation & strength |
| Phosphorus (P) | – | 0.040 | ≤0.010 | Minimized for toughness |
| Sulfur (S) | – | 0.040 | ≤0.008 | Critical for sour service |
| Silicon (Si) | 0.15 | 0.35 | 0.20-0.30 | Deoxidation agent |
| Chromium (Cr) | 0.80 | 1.10 | 0.85-1.05 | Hardenability & corrosion resistance |
| Molybdenum (Mo) | 0.15 | 0.25 | 0.18-0.23 | Temper resistance & toughness |
Mechanical Properties (Quenched & Tempered Condition)
🔥 Tensile Properties
- Yield Strength: 655-895 MPa (95-130 ksi)
- Tensile Strength: 795-1030 MPa (115-150 ksi)
- Elongation: ≥12% (in 2 inches)
- Reduction of Area: ≥35%
🛡️ Hardness & Toughness
- Hardness: 22-32 HRC (NACE compliant ≤22 HRC for sour service)
- Impact Energy: ≥27 J (20 ft-lbs) at -46°C (-50°F)
- Grain Size: ASTM E112 Grade 5 or finer
NACE MR0175 Compliance: When properly heat treated and controlled to ≤22 HRC, AISI 4142 provides excellent resistance to sulfide stress cracking (SSC) in sour environments. Our ShunFu manufacturing capabilities ensure consistent hardness distribution throughout the entire cross-section.
🏭 Manufacturing & Quality Control Excellence
⚒️ Forging Ratio ≥4:1
All forgings maintain minimum 4:1 reduction ratio ensuring core density and eliminating centerline porosity common in smaller forging ratios.
🔥 Controlled Heat Treatment
Computer-controlled quenching (oil or polymer) followed by precise tempering cycles guarantee uniform mechanical properties across entire cross-sections.
🔍 UT Class C/c Testing
100% ultrasonic testing per ASTM A388 or SEP 1921 Class C/c standard, detecting flaws ≥1.6mm (1/16″) diameter equivalency.
📊 Statistical Process Control
Real-time monitoring of critical parameters including austenitizing temperature, quench rate, and tempering temperature with ±5°C accuracy.
Heat Treatment Process Parameters
| Process Stage | Temperature Range | Holding Time | Cooling Method | Purpose |
|---|---|---|---|---|
| Austenitizing | 845-870°C (1550-1600°F) | 1 hour per inch thickness | Oil or Polymer Quench | Martensite formation |
| Tempering | 540-650°C (1000-1200°F) | 2 hours minimum | Air cooling | Desired hardness/toughness balance |
| Stress Relief (Optional) | 580-620°C (1075-1150°F) | 1 hour per inch | Furnace cool to 300°C | Residual stress reduction |
🔧 Processing & Value-Added Services
SHUNFU METAL’s integrated manufacturing facility offers comprehensive processing capabilities to deliver drill-ready components. Our hollow bar inventory includes AISI 4142 in various configurations optimized for different drilling applications.
🕳️ BTA Deep Hole Boring
- Diameters: 25-500mm (1″-20″)
- Length capability: Up to 12 meters
- Surface finish: Ra 1.6-3.2 μm
- Straightness: ≤0.5mm/meter
⚙️ CNC Machining Services
- Rough turning (optimized for UT testing)
- Precision peeling (surface finish Ra 0.8 μm)
- Thread cutting (API 7-1 connections)
- Custom end configurations
🧪 Third-Party Testing
- Chemical analysis (OES method)
- Mechanical property verification
- Charpy impact testing at service temperature
- Macro/micro structure analysis
📦 Custom Packaging
- Anti-corrosion coating application
- End protection (threaded or plain)
- Bundling per customer specifications
- Marking per API/customer requirements
🛢️ Applications in Oilfield Operations
Primary Applications
| Application | Operating Environment | Critical Requirements | AISI 4142 Advantages |
|---|---|---|---|
| Drill Collars | High torque, compression loads | Fatigue resistance, UT Class C/c | Excellent hardenability, uniform properties |
| Tool Joints | High stress concentration areas | Impact toughness, wear resistance | Superior notch toughness after Q+T |
| Wellhead Equipment | Pressure containment, sour service | API 6A compliance, SSC resistance | NACE MR0175 qualified, low S/P content |
| Subsea Components | Seawater corrosion, high pressure | Corrosion fatigue resistance | Chromium content provides enhanced corrosion resistance |
| Valve Bodies | Cyclic loading, pressure cycles | Dimensional stability, machinability | Excellent response to heat treatment |
Performance in Extreme Environments
AISI 4142’s chromium-molybdenum composition provides exceptional performance in harsh oilfield conditions. The molybdenum content (0.15-0.25%) significantly improves temper resistance, allowing the steel to maintain its mechanical properties at elevated service temperatures up to 150°C (300°F). The chromium content enhances hardenability, ensuring uniform properties even in large cross-sections typically required for drill collar applications.
📏 Size Range & Delivery Conditions
| Product Form | Diameter Range | Length Range | Surface Finish | Typical Lead Time |
|---|---|---|---|---|
| Hot Rolled Bar | 25-300mm (1″-12″) | 3-12 meters | Black/Scaled | 4-6 weeks |
| Forged Bar | 100-800mm (4″-32″) | 1-6 meters | Black/Scaled | 6-8 weeks |
| Peeled Bar | 25-500mm (1″-20″) | 3-12 meters | Ra 1.6-3.2 μm | 5-7 weeks |
| Rough Turned | 50-600mm (2″-24″) | 2-8 meters | Ra 6.3-12.5 μm | 5-7 weeks |
| Hollow Bar (BTA) | OD: 100-500mm, ID: 25-300mm | 3-12 meters | Ra 1.6-3.2 μm (ID) | 8-10 weeks |
Stock Availability: SHUNFU maintains strategic inventory of popular AISI 4142 sizes in Q+T condition for faster delivery. Contact our technical sales team for current stock levels and expedited delivery options.
❓ Frequently Asked Questions
Q: Can AISI 4142 be used in sour service environments?
Yes, AISI 4142 is NACE MR0175 compliant when properly heat treated to maintain hardness ≤22 HRC. Our controlled tempering process ensures consistent hardness distribution, making it suitable for H₂S environments with partial pressure up to 0.05 psia.
Q: What is the maximum section thickness that can achieve uniform properties?
Due to its excellent hardenability from chromium and molybdenum content, AISI 4142 can achieve uniform mechanical properties through sections up to 150mm (6″) diameter when oil quenched, and up to 100mm (4″) when water quenched.
Q: How does AISI 4142 compare to AISI 4140 for drill collar applications?
AISI 4142 contains slightly higher carbon (0.38-0.45% vs 0.38-0.43%) providing increased strength while maintaining excellent toughness. This makes 4142 preferred for applications requiring higher yield strength without compromising impact resistance.
Q: What ultrasonic testing standards do you apply?
We perform 100% UT inspection per ASTM A388 Class C/c or SEP 1921 Class C/c, detecting reflectors ≥1.6mm (1/16″) diameter equivalency. All bars are tested in the rough-turned condition for optimal ultrasonic penetration.
Q: Can you provide material traceability documentation?
Yes, each shipment includes complete mill test certificates (MTC) with heat analysis, mechanical properties, heat treatment records, and NDT results. We maintain full traceability from raw material procurement through final inspection.
Q: What are your standard tolerances for forged bars?
Standard forging tolerances are +5/-0mm on diameter with straightness ≤2mm/meter. For applications requiring tighter tolerances, we offer precision peeling or rough turning services to achieve ±0.5mm diameter tolerance.
Ready to Source Premium AISI 4142 Steel?
Get competitive pricing and fast delivery from China’s leading oil & gas steel manufacturer. Our technical sales team is ready to assist with material selection, specifications, and custom processing requirements.
📞 Call: +86-731-89903933 | 📧 Email: [email protected]
Request quote with your specifications – diameter, length, quantity, delivery requirements
We are committed to integrate steel resources in china and serve the global steel market. Our company has more than 15 years of experience in steel researching, production, managing and sales. And our team mostly are based on and worked in national famous steel enterprise before. In the aspect of resources and information, we have established cooperative relationship with nearly hundred enterprises, either state-owned or private owned in China.
What’s more, we have built long, deep and close business relationship with dozens of steel company, Sharing and holding equities with several steel enterprises. Because of the close cooperation with steel companies and our pioneering spirit, which can ensure us stay at the top competition, and ensure our customers get what they really want. We provide preffesional one-stop service to the Contractors of follows project:
- Oil and Gas Pipeline Construction
- Onshore and Offshore
- Boiler Manufacturers
- Oil Refining Equipment
- Petroleum and Chemical Plant Construction
- Fire Protection
- Heating & Air Conditioning
Our ability to purchase materials directly from leading mills at the best possible price will give you the competitive edge. This coupled with a skilled workforce dedicated to embracing the demands of the markets we serve. Just give us a call +86-731-89903933.
