AISI 4130 P+X — Advanced Performance Low Alloy Chromium-Molybdenum Steel

Product Description

SHUNFU METAL’s AISI 4130 P+X is our proprietary enhanced-performance variant of the traditional 4130 low alloy Chromium-Molybdenum (CrMo) steel, specifically developed for critical oil field applications requiring superior toughness, improved fatigue resistance, and enhanced H₂S resistance. Building on the excellent properties of standard 4130 steel, our P+X technology incorporates premium melting practices, optimized chemistry control, and advanced heat treatment protocols to deliver significantly improved performance in demanding environments.

The P+X (Performance + X-factor) process combines precision melting, refined microstructure control, and proprietary heat treatment techniques to achieve a unique balance of strength, toughness, and resistance to hydrogen sulfide environments. As an API Q1 certified manufacturer with fully calibrated and certified heat treatment furnaces, SHUNFU METAL ensures that every AISI 4130 P+X bar meets or exceeds the most stringent industry requirements, including API 6A PSL 3&4 and NACE MR0175. Each batch undergoes comprehensive testing by CNSA (China National Standards Association) to verify compliance, providing our customers with complete confidence in material performance for the most critical applications.

P+X Technology Advantage

Our exclusive P+X technology elevates standard AISI 4130 to exceptional performance levels through:

• Enhanced Cleanliness: Advanced melting and refining techniques reduce inclusion content by up to 40% compared to standard 4130, resulting in superior fatigue properties and improved ultrasonic inspectability
• Optimized Microstructure: Carefully controlled cooling rates and proprietary heat treatment cycles produce a refined, homogeneous tempered martensitic structure with uniform carbide distribution
• Improved Grain Refinement: Consistently finer grain size (ASTM 7-8) than standard 4130, enhancing both strength and toughness
• Superior H₂S Resistance: Specialized processing and precise chemistry control increase resistance to sulfide stress cracking in sour service environments
• Enhanced Through-Thickness Properties: Uniform mechanical properties from surface to core even in large diameter bars
• Extended Fatigue Life: P+X processed material demonstrates 30-40% longer fatigue life in cyclic loading applications

Key Advantages

• Superior Toughness: 20-30% higher impact values at low temperatures compared to standard 4130
• Excellent Weldability: Lower carbon content (0.28-0.33%) enables better weldability with reduced risk of cracking
• Enhanced Machinability: Optimized chemistry and microstructure for improved machinability while maintaining superior mechanical properties
• Better Fatigue Performance: Refined microstructure and reduced inclusion content provide significantly improved fatigue resistance
• Improved Sour Service Performance: Enhanced resistance to hydrogen embrittlement and sulfide stress cracking
• Guaranteed Consistency: API Q1 certified manufacturing with comprehensive quality control at every production stage
• Certified Heat Treatment: Controlled quenching and tempering in calibrated furnaces with precise temperature control
• 100% Ultrasonic Testing: Complete quality assurance with ASTM A388 ultrasonic inspection to API 6A PSL 3&4 standards
• CNSA Verified: Each batch independently tested by China National Standards Association for guaranteed compliance
• Full Traceability: Complete documentation from melt to final inspection for every bar

Chemical Composition

SHUNFU METAL’s AISI 4130 P+X steel is manufactured with precisely controlled chemistry to ensure optimal properties:

Element	Minimum %	Maximum %
Carbon (C)	0.28	0.33
Chromium (Cr)	0.80	1.10
Manganese (Mn)	0.40	0.60
Molybdenum (Mo)	0.15	0.25
Phosphorus (P)	–	0.020
Sulfur (S)	–	0.020
Silicon (Si)	0.15	0.35

P+X Refinement: While maintaining the standard chemical composition range of AISI 4130, our P+X process features:

• Tighter control of residual elements for enhanced performance
• Reduced phosphorus and sulfur maximums (0.020% vs. standard 0.035/0.040%)
• Optimized balance of alloying elements within specification ranges
• Additional microalloying elements within standard composition limits to improve grain refinement
• Controlled calcium treatment for improved inclusion shape control

Mechanical Properties

SHUNFU METAL’s AISI 4130 P+X steel bars in hardened and tempered condition (75ksi variant) deliver the following enhanced mechanical properties:

Property	Standard 4130	4130 P+X
0.2% Yield Strength (min)	75 ksi (517 MPa)	75 ksi (517 MPa)
Ultimate Tensile Strength (min)	95 ksi (655 MPa)	95 ksi (655 MPa)
Elongation (min)	18%	20%
Reduction of Area (min)	35%	45%
Hardness (HRC)	18-22	18-22
Hardness (HBW)	217-237	217-237

Enhanced Impact Properties

Test Temperature	Standard 4130 (Average)	4130 P+X (Average)
Charpy V-Notch @ 23°C (73°F)	100 J (74 ft-lb)	130 J (96 ft-lb)
Charpy V-Notch @ -60°C (-76°F)	27 J (20 ft-lb)	35 J (26 ft-lb)
Charpy V-Notch @ -75°C (-103°F)	19 J (14 ft-lb)	25 J (18 ft-lb)

Additional P+X Performance Characteristics

• Improved Fatigue Strength: 15-20% higher endurance limit in rotating beam tests
• Enhanced SSC Resistance: Passes NACE TM0177 Method A testing at higher stress levels
• Better Fracture Toughness: Higher KIC values through superior microstructural control
• Improved Through-Thickness Uniformity: Less than 10% variation in properties from surface to core
• Enhanced Tempering Resistance: Better property retention at elevated temperatures

Note: All properties are achieved using SHUNFU METAL’s enhanced QTC (Quench, Temper, and Control) procedure in accordance with API 6A requirements and our proprietary P+X protocols. Our certified heat treatment furnaces ensure consistent mechanical properties throughout the entire production lot.

Manufacturing Process

SHUNFU METAL’s AISI 4130 P+X steel undergoes our proprietary manufacturing process to ensure premium quality:

P+X Enhanced Steel Production

• Premium Melting: Electric Arc Furnace (EAF) with advanced chemistry control systems
• Enhanced Refining: Extended Ladle Refining with additional desulfurization for superior cleanliness
• Optimized Degassing: Extended Vacuum Degassing to achieve hydrogen levels below 2ppm
• Controlled Casting: Optimized casting parameters for improved solidification structure
• Higher Reduction Ratio: Minimum 6:1 reduction ratio (vs. standard 4:1) for enhanced grain flow and mechanical properties
• Controlled Rolling: Precise temperature control during hot working for optimized microstructure

P+X Heat Treatment

• Precision Austenitizing: Computer-controlled heating with uniform soak at optimized temperatures
• Advanced Quenching: Enhanced quenching protocols with precisely controlled cooling rates
• Specialized Tempering: Multi-stage tempering process for optimal balance of strength and toughness
• Digital Monitoring: Continuous digital recording of complete heat treatment cycles
• Certified Furnaces: All heat treatment performed in API-certified and regularly calibrated furnaces

Enhanced Quality Assurance

• 100% Ultrasonic Testing: Advanced ultrasonic inspection exceeding API 6A PSL 3&4 requirements
• Microstructural Verification: Detailed metallographic examination to verify grain size (ASTM 7-8) and proper microstructure
• Enhanced Mechanical Testing: Comprehensive testing including core property verification on larger diameters
• CNSA Independent Verification: Each batch tested by China National Standards Association
• Extended Documentation: Comprehensive certification package including detailed processing records

Applications

AISI 4130 P+X steel from SHUNFU METAL is specifically designed for critical applications where standard 4130 may be approaching its performance limits:

Critical Oil and Gas Applications

• High-Pressure Wellhead Components: Superior resistance to fatigue and environmental cracking
• Sour Service Equipment: Enhanced performance in H₂S-containing environments
• Safety-Critical BOP Components: Improved reliability for blowout preventer systems
• Completion Tools: Better resistance to downhole conditions and cyclic loading
• Subsea Equipment: Enhanced corrosion fatigue resistance in marine environments
• Heavy-Wall Pressure Containing Components: Improved through-thickness properties

Other High-Performance Applications

• Critical Aerospace Components: Superior fatigue life and reliability
• Heavy-Duty Automotive Parts: Enhanced durability for high-stress applications
• Large Industrial Equipment: Improved performance in critical load-bearing components
• Defense Applications: Superior reliability in mission-critical systems
• High-Stress Fasteners: Better fatigue and environmental performance

Specifications and Compliance

SHUNFU METAL’s AISI 4130 P+X steel meets or exceeds the following specifications:

• ASTM A29/A29M: Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought
• ASTM A322: Standard Specification for Steel Bars, Alloy, Standard Grades
• API 6A: Specification for Wellhead and Tree Equipment
• NACE MR0175/ISO 15156: Materials for use in H₂S-containing environments
• SAE J404: Chemical Compositions of SAE Alloy Steels
• ASTM A388: Standard Practice for Ultrasonic Examination of Steel Forgings

Additional P+X Certifications

• API Q1: American Petroleum Institute Quality Management System
• ISO 9001: Quality Management System
• CNSA: China National Standards Association verification
• NACE TM0177: Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking
• Enhanced Material Qualification: Extended property verification beyond standard requirements

Product Forms and Sizes

SHUNFU METAL offers AISI 4130 P+X steel in the following forms:

Hot Rolled Bars

• Diameter Range: 3″ to 12″ (76.2mm to 304.8mm)
• Surface Conditions: Peeled or Smooth Turned
• Heat Treatment: P+X enhanced hardening and tempering to meet 75ksi minimum yield, 22HRc maximum (NACE MR0175 compliant)
• Straightness: 1mm in 500mm (1/8″ in 5″)
• Enhanced straightness available upon request

Machining Tolerances

For ‘Machining Quality Bar’ to ASTM A29 Tolerances, the minimum machining allowance is as follows:

Ordered Surface Condition	Minimum Stock Removal
Peeled/Smooth Turned	1% per side

Note: For bars larger than 11.25″ (285.8mm) diameter, we perform additional core verification testing to ensure through-thickness property consistency.

Technical Support and Services

SHUNFU METAL provides comprehensive technical support to help customers maximize the performance of our AISI 4130 P+X steel:

• Application-Specific Guidance: Expert recommendations on material selection for demanding applications
• Custom Property Development: Tailored heat treatment to optimize properties for specific requirements
• Failure Analysis: Advanced metallurgical investigation of material-related issues
• Enhanced Testing Services: Specialized mechanical and environmental testing capabilities
• Welding Technical Support: Detailed guidelines for welding procedures and filler selection
• Machining Recommendations: Optimized parameters for efficient machining
• Research Collaboration: Joint development projects for advanced applications
• Field Performance Monitoring: Assistance with in-service performance evaluation
• Comprehensive Documentation: Detailed certification packages with processing history

P+X vs. Standard 4130: Comparative Advantages

Understanding how AISI 4130 P+X compares to standard 4130 helps in selecting the optimal material for specific applications:

Performance Characteristic	Standard 4130	4130 P+X Advantage
Low Temperature Toughness	Good	Superior (20-30% higher CVN values)
Fatigue Resistance	Standard	Enhanced (15-20% higher endurance limit)
H₂S Resistance	NACE compliant	Enhanced SSC resistance at higher stress levels
Microstructural Uniformity	Standard	Improved homogeneity and finer grain size
Through-Thickness Properties	Moderate variation	Minimal variation from surface to core
Cleanliness Level	Standard	Premium (reduced inclusion content)
Weldability	Good	Good with enhanced HAZ toughness
Ultrasonic Inspectability	Standard	Improved signal-to-noise ratio
Quality Documentation	Standard	Enhanced with detailed process records
Cost Factor	Base	Premium (10-15% higher)

Why Choose SHUNFU METAL for AISI 4130 P+X

Selecting SHUNFU METAL as your supplier for AISI 4130 P+X steel provides significant advantages:

• Proprietary P+X Technology: Our exclusive processing technology delivers superior performance in critical applications
• API Q1 Certification: Manufacturing processes certified to API Q1 quality management system
• Certified Heat Treatment Facilities: Heat treatment furnaces are regularly calibrated and certified, ensuring precise temperature control
• Enhanced QTC Qualification: Advanced Quench, Temper, and Control procedures qualified according to API 6A
• CNSA Independent Verification: Each batch undergoes third-party testing by China National Standards Association
• Superior Consistency: Tighter process controls ensure batch-to-batch consistency
• Comprehensive Testing: Enhanced testing protocols beyond standard requirements
• Technical Expertise: Specialized knowledge in high-performance alloy applications
• Complete Traceability: Full documentation from melt to final inspection
• Performance Guarantee: Assured material performance in specified applications

Request Information

Contact SHUNFU METAL today to discuss your AISI 4130 P+X requirements. Our technical team is ready to assist you with:

• Detailed technical specifications
• Material selection guidance for critical applications
• Custom property requirements
• Price quotations and delivery schedules
• Technical support for your application
• Comparison testing against standard materials