Project Description
Overview of P750 Nonmagnetic Steel
P750 nonmagnetic steel is a high-alloy austenitic chromium-nickel-nitrogen (Cr-Ni-N) stainless steel, specifically engineered for the rigorous demands of oil and gas drilling environments. Characterized by its extremely low carbon content and enriched with high levels of chromium, nickel, and nitrogen, P750 delivers an exceptional combination of mechanical strength and severe pitting corrosion resistance comparable to premium nickel-based alloys.
Its fundamentally austenitic microstructure ensures absolute non-magnetic stability, with a relative magnetic permeability of ≤ 1.001, preventing any interference with downhole directional measurement tools (MWD / LWD). Through a specialized cold-working process, P750 achieves superior yield and tensile strengths across the full length of the component, maintaining structural integrity under high-pressure downhole conditions. This unique synergy of non-magnetic reliability, mechanical robustness, and advanced corrosion protection makes P750 the definitive material for critical drilling components where both magnetic transparency and operational longevity are non-negotiable. Explore our complete non-magnetic steel product range for various downhole applications.
| Standard / System | Equivalent Grade / Trade Name |
|---|---|
| Shunfu Metal Designation | P750 |
| Common Market Designation | P750 Non-Magnetic Steel |
| Material Category | Austenitic Cr-Ni-N Stainless Steel |
Applications in Directional Drilling
The unique properties of P750 nonmagnetic steel make it indispensable for several critical applications in modern directional drilling and exploration operations. Its reliability under extreme stress ensures safety and precision.
- Non-magnetic drill collars (NMDC) for directional drilling
- MWD and LWD tool housings
- Non-magnetic stabilizers and mandrels
- Non-magnetic drill pipe (NMDP) joints and subs
- Directional drilling bottom-hole assemblies (BHA)
- Mining exploration drill rods and heavy-duty casing
- Non-magnetic hollow bars for downhole tool manufacturing
- Rock drilling steel components for extreme-depth mining operations
Specifications & Industry Standards
P750 nonmagnetic steel is produced and tested in strict accordance with international standards, ensuring full compliance for global oilfield operations.
| Standard | Specification / Reference | Product Shape |
|---|---|---|
| API | API Spec 7-1 | Drill Collars, Drill Stem Components |
| ASTM | ASTM A262 (Practices A & E) | Corrosion Testing Reference for Bars/Hollows |
| ASTM | ASTM E114 | Ultrasonic Inspection Standard for Bars/Hollows |
Available Sizes & Delivery Options
Shunfu Metal supplies P750 nonmagnetic steel in a comprehensive range of dimensions to meet diverse downhole requirements. Available product forms include hot-rolled and forged round bars, flat bars, and non-magnetic hollow bars. We accommodate custom diameters and lengths, demonstrating our robust processing capabilities. Our facilities feature API-standard regularly calibrated heat treatment furnaces, alongside advanced precision machining equipment including BTA deep hole boring machines, CNC lathes and milling machines, and long-distance gunhole drilling systems.
- Ready Stock (Common Sizes)
- Available for immediate shipment, minimum order quantity (MOQ) of one single piece, delivery within approximately 7 days.
- Custom Forgings / Rolled Material
- MOQ typically starts at 3 tons, with a delivery lead time of approximately 30 days.
- Small Batch Special Grades
- Melted via our small induction furnace, starting from 3-5 tons per heat.
- Large Volume Orders
- Produced rapidly utilizing our 30-60 ton electric arc furnaces (EAF) for efficient, high-volume delivery.
Chemical Composition of P750
The carefully balanced chemistry of P750 ensures its austenitic stability and outstanding resistance to localized corrosion.
| Element | Content (%) |
|---|---|
| Carbon (C) | max. 0.03 |
| Manganese (Mn) | 1.50 - 3.00 |
| Chromium (Cr) | 26.50 - 29.50 |
| Molybdenum (Mo) | 2.00 - 4.00 |
| Nitrogen (N) | min. 0.20 |
| Nickel (Ni) | 28.00 - 31.50 |
Melting & Processing Routes
Shunfu Metal offers flexible melting routes for P750 to align with your specific application demands, whether you require standard oilfield components or ultra-premium corrosion-resistant alloy grade performance.
- Conventional Route: EAF + AOD + LF + VD, ensuring precise carbon control and nitrogen adjustment required for this austenitic stainless steel.
- Elevated Purity: ESR (Electroslag Remelting) or PESR for reduced inclusion content and improved homogeneity.
- Critical-Service Premium: VIM + VAR (Vacuum Induction Melting + Vacuum Arc Remelting) for the most demanding downhole environments.
Customers can consult with our metallurgical team to determine the optimal melting solution for their project requirements.
Mechanical Properties
All values are tested at room temperature, achieved by a special cold-working process over the full length to ensure consistent downhole performance.
| Property | OD up to 9 1/4" | OD 9 1/2" and larger | General Values |
|---|---|---|---|
| Yield Strength (0.2% offset) | min. 140 ksi (965 N/mm²) | min. 130 ksi (900 N/mm²) | - |
| Tensile Strength | - | - | min. 150 ksi (1035 N/mm²) |
| Elongation | - | - | min. 17% |
| Reduction of Area | - | - | min. 50% |
| Impact Energy | - | - | min. 135 J (100 ft.lb) |
| Endurance Strength (N=10⁵) | - | - | ± 550 N/mm² (± 80 ksi) |
| Hardness (Brinell) | - | - | 300 - 400 HB |
Heat Treatment Protocols
Proper thermal processing is vital to maintaining the austenitic structure and achieving the targeted mechanical properties of P750.
| Heat Treatment Process | Application / Purpose | Cooling Method |
|---|---|---|
| Solution Annealing / Quenching | Applied after warm forging to prevent material sensitization and restore full austenitic structure | Water Quenching |
| Cold Working | Specialized process over the full length to achieve required yield and tensile strengths | Ambient / Mechanical |
Surface Finish & Machining Capabilities
To maximize the operational lifespan of P750 components, Shunfu Metal provides comprehensive surface finishing and precision machining services. We offer turning, grinding, and milling to achieve precise dimensional tolerances down to ±0.01mm and surface roughness (Ra) values as low as 0.4μm. For internal diameters, our BTA deep hole boring and long-distance gunhole drilling ensure superior concentricity.
Critically for P750, we perform specialized surface treatments such as roller burnishing, shot peening, and hammer peening, which induce compressive residual stresses to effectively prevent transgranular stress corrosion cracking (SCC). Combined with our CNC lathe and milling capabilities, we deliver fully finished, downhole-ready drill collars and hollow bars.
Quality Assurance & Inspection
Shunfu Metal enforces rigorous quality control across pre-production, in-process, and post-production stages. All P750 products undergo 100% volumetric ultrasonic inspection according to ASTM E114 to verify internal structural integrity. Magnetic permeability is 100% verified via proprietary probe-testing, with results certified on printouts guaranteeing a relative permeability of ≤ 1.001.
Intergranular corrosion resistance is validated strictly per ASTM A262 (Practices A & E). Comprehensive testing includes chemical composition analysis, mechanical property evaluation, dimensional checks, and metallographic examination. We issue EN 10204 3.1 certificates standardly, with 3.2 certificates available upon request. Third-party inspections by SGS or TÜV can be arranged. Learn more about our corporate commitment to excellence on the ShunFu Metal about page. All processes operate under our API Q1 and ISO 9001 certified quality management systems.
Packing & Shipping Protocols
Shunfu Metal ensures secure delivery of P750 products through tailored packing protocols. Black-skin (as-forged/rolled) bars are securely fastened with steel wire bundles, structurally reinforced to prevent any shifting or container damage during transit.
For bright-surface and precision-machined components, such as finished drill collars and hollow bars, we utilize multiple protective packaging materials—including wooden cases and shock-absorbing wraps—to safeguard surface roughness and dimensional integrity. Comprehensive anti-rust measures, including the application of specialized rust-preventative oil, are mandatory to guarantee that the material remains entirely free from oxidation throughout the entire overseas maritime shipping process.
Request P750 Nonmagnetic Steel Quotes
Secure your downhole operations with industry-leading magnetic transparency and corrosion resistance. Our technical team is ready to assist with custom specifications, melting routes, and immediate shipment requests.
Request a Quote for P750 SteelFrequently Asked Questions
Can you supply P750 nonmagnetic steel to API specification?
Yes. As an API Q1 certified manufacturer, Shunfu Metal produces P750 drill collars and hollow bars fully compliant with API Spec 7-1 requirements, ensuring they meet the rigorous dimensional and mechanical standards for drill stem components.
What is the minimum order quantity for P750 nonmagnetic steel?
For ready stock items, we support a minimum order quantity of just one single piece. For custom forged or rolled requirements, the MOQ is typically 3 tons. We also offer small-batch melting from 3-5 tons via our induction furnace for specialized projects.
How is the non-magnetic property of P750 verified?
Every single P750 collar and bar is 100% tested using our proprietary probe-testing process. The magnetic permeability is certified and provided with a printout, guaranteeing a relative permeability of ≤ 1.001 for downhole magnetic transparency.
What surface treatments do you apply to prevent stress corrosion cracking (SCC)?
To prevent transgranular SCC, we offer specialized surface treatments including hammer peening, roller burnishing, and shot peening. For intergranular SCC, sensitization is prevented by water quenching immediately after warm forging, and each piece is tested per ASTM A262 Practices A and E.