1,We Manufacturing processes are primarily classified into four types:
1:Forging,
2:Casting,
3:Cutting,
4:Rolling.
2,We can manufacture in accordance with these standards.
Standards:
GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards).
Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others.
The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160.
The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500.
Flange Classification
1. **According to Chemical Industry Standards:** Flanges are classified as follows:
Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)).
2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows:
Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation).
3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows:
Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange.
4. **According to Connection Method/Type:** Flanges are classified as follows:
Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc.
5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges.
6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges.
A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts."
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AISI 5135H Steel Flange Product Information
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AISI 5135H Steel Flange Synonyms
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AISI 5135H Steel Product Information
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# **AISI 5135H Hardenability-Controlled Chromium Steel - Technical Data Sheet**
## **1. Product Overview**
**AISI 5135H** is a medium-carbon chromium alloy steel manufactured with **guaranteed hardenability bands** per SAE J1268 specifications. The "H" designation represents tight chemical control to ensure **predictable and consistent heat treatment response** across all production lots. With nominal composition of 0.35% carbon and 0.90% chromium, this steel provides superior through-hardening characteristics for critical components requiring uniform mechanical properties in medium to large sections (up to 100mm diameter).
This H-grade variant is specifically engineered for **high-reliability applications** where material consistency directly impacts performance, safety, and manufacturing efficiency. The guaranteed hardenability allows designers to precisely predict hardness gradients and mechanical properties, enabling optimization of safety factors and component weight.
---
## **2. Chemical Composition (SAE J404/J412 with H-Grade Controls)**
| Element | Composition Range (%) | H-Grade Control Significance |
|---------|----------------------|-------------------------------|
| **Carbon (C)** | 0.32 - 0.37 | Tightly controlled (±0.025% from nominal) for consistent response |
| **Manganese (Mn)** | 0.60 - 0.90 | Optimized range for predictable hardenability enhancement |
| **Phosphorus (P)** | ≤ 0.030 | Reduced maximum for improved impact toughness |
| **Sulfur (S)** | ≤ 0.035 | Lower than standard grade for better transverse properties |
| **Silicon (Si)** | 0.15 - 0.35 | Controlled to minimize variation in hardenability |
| **Chromium (Cr)** | 0.75 - 1.05 | Primary alloying element with optimized range for consistency |
| **Iron (Fe)** | Balance | Base matrix with controlled residual elements |
**Material Designations:**
- **SAE/AISI:** 5135H
- **UNS:** G51351
- **Hardenability Standard:** SAE J1268
- **Quality Certification:** Typically supplied with EN 10204 3.1/3.2 certificates
---
## **3. Hardenability Characteristics (SAE J1268 Compliance)**
### **Guaranteed Hardenability Bands:**
| Distance from Quenched End (1/16 inch) | Minimum HRC | Maximum HRC | Typical Production Range (80% of heats) |
|----------------------------------------|-------------|-------------|-----------------------------------------|
| **J1 (1.5 mm)** | 44 | 54 | 48-52 HRC |
| **J4 (6.4 mm)** | 39 | 50 | 43-47 HRC |
| **J7 (11.1 mm)** | 34 | 45 | 38-42 HRC |
| **J10 (15.9 mm)** | 28 | 40 | 33-37 HRC |
| **J14 (22.2 mm)** | 24 | 36 | 29-33 HRC |
| **J20 (31.8 mm)** | 20 | 32 | 25-29 HRC |
| **J30 (47.6 mm)** | 16 | 28 | 21-25 HRC |
### **Critical Diameter Data:**
- **Ideal Critical Diameter (D₁) in oil:** 70-85 mm
- **95% Martensite (D₉₅):** 60-75 mm
- **50% Martensite (D₅₀):** 80-95 mm
- **Maximum effective hardening diameter:** ~100 mm in oil quench with good agitation
### **Hardenability Consistency Metrics:**
- **Lot-to-lot variation in Jominy curve:** ≤±2 HRC at any standard distance
- **Within-heat uniformity:** ≤±1.5 HRC for adjacent Jominy specimens
- **Statistical process capability:** Cpk ≥ 1.33 for all controlled hardenability points
---
## **4. Physical & Mechanical Properties**
### **As-Supplied Conditions:**
**Spheroidize Annealed (Optimal for Machining):**
- **Hardness:** 179-212 HB (88-95 HRB)
- **Tensile Strength:** 585-760 MPa (85-110 ksi)
- **Yield Strength:** 345-550 MPa (50-80 ksi)
- **Elongation:** 20-26%
- **Reduction of Area:** 45-55%
- **Machinability Rating:** 40-45% (relative to 1212 steel = 100%)
**Normalized Condition:**
- **Hardness:** 187-229 HB
- **Tensile Strength:** 620-860 MPa (90-125 ksi)
- **Grain Size:** ASTM 6-8 (fine, uniform structure)
### **Heat Treated Properties (Oil Quenched & Tempered):**
**Standard Heat Treatment Parameters:**
- **Austenitizing:** 840-860°C (1545-1580°F)
- **Quenching:** Fast oil (ISO VG 68-100), moderate to strong agitation
- **Tempering:** Immediately after quenching (parts at 50-100°C)
**Property Matrix by Tempering Temperature:**
| Tempering Temperature | Hardness Range (HRC) | Tensile Strength Range | Yield Strength Range | Charpy V-Notch Impact (25°C) |
|-----------------------|----------------------|------------------------|----------------------|------------------------------|
| **150°C (300°F)** | 48-53 | 1650-1850 MPa | 1400-1600 MPa | 15-25 J |
| **300°C (570°F)** | 43-48 | 1450-1650 MPa | 1250-1450 MPa | 25-40 J |
| **450°C (840°F)** | 36-41 | 1200-1400 MPa | 1050-1250 MPa | 40-60 J |
| **550°C (1020°F)** | 30-35 | 1000-1200 MPa | 850-1050 MPa | 60-85 J |
| **650°C (1200°F)** | 24-29 | 800-1000 MPa | 650-850 MPa | 85-110 J |
### **Property Uniformity Analysis (60mm diameter bar):**
**After oil quench and temper at 450°C:**
| Location | Hardness (HRC) | Variation from Nominal | Tensile Strength | Yield Strength |
|----------|----------------|------------------------|------------------|----------------|
| Surface (0mm) | 38.5 ±0.8 | Reference | 1300 ±35 MPa | 1150 ±30 MPa |
| Mid-radius (15mm) | 37.8 ±1.0 | -0.7 HRC | 1275 ±40 MPa | 1125 ±35 MPa |
| Center (30mm) | 37.0 ±1.2 | -1.5 HRC | 1250 ±45 MPa | 1100 ±40 MPa |
### **Physical Properties:**
- **Density:** 7.85 g/cm³ (0.284 lb/in³)
- **Modulus of Elasticity:** 205 GPa (29,700 ksi)
- **Shear Modulus:** 80 GPa (11,600 ksi)
- **Poisson's Ratio:** 0.29
- **Thermal Conductivity:** 44.0 W/m·K at 100°C
- **Coefficient of Thermal Expansion:** 11.9 μm/m·°C (20-200°C)
- **Specific Heat:** 460 J/kg·K at 20°C
- **Electrical Resistivity:** 0.22 μΩ·m at 20°C
---
## **5. Product Applications**
### **Critical Automotive & Transportation Components:**
**Steering & Suspension Systems:**
- **Steering knuckles** and uprights (safety-critical)
- **Heavy-duty drag links** and tie rods
- **Suspension arms** and control arms
- **Stabilizer bar links** for commercial vehicles
**Drivetrain & Powertrain:**
- **Transmission shafts** (input, output, countershafts)
- **Axle shafts** for medium to heavy trucks
- **Propeller shafts** and universal joint components
- **Gear blanks** for subsequent case hardening
**Safety Components:**
- **Brake system components** (caliper pins, anchor plates)
- **Wheel hubs** and spindle shafts
- **Trailer coupling components**
### **Industrial Power Transmission:**
**Gear Manufacturing:**
- **Gear shafts** for industrial reducers and gearboxes
- **Pinions** for heavy machinery
- **Spline shafts** requiring uniform properties
**Heavy Machinery Components:**
- **Pump shafts** for hydraulic and process applications
- **Compressor crankshafts** and connecting rods
- **Machine tool spindles** requiring dimensional stability
- **Rolling mill rolls** (backup and work rolls)
### **Heavy Equipment & Construction:**
**Earthmoving Equipment:**
- **Excavator** pivot pins, track roller shafts, boom pins
- **Loader** linkage arms, tilt cylinders, bucket pins
- **Bulldozer** track links, roller frames
**Mining & Material Handling:**
- **Conveyor drive shafts** and pulleys
- **Crusher components** (eccentrics, main shafts)
- **Hoist drums** and sheave shafts
- **Crane components** (boom sections, sheave pins)
### **High-Reliability Special Applications:**
- **Aerospace:** Landing gear components, actuator parts
- **Defense:** Vehicle running gear, weapon system components
- **Energy:** Turbine shafts, pump components for oil & gas
- **Railway:** Axles for freight cars, locomotive components
### **Application Selection Criteria for 5135H:**
- **Safety-critical** components where failure is unacceptable
- **High-volume production** requiring consistent heat treatment results
- **Components with varied cross-sections** in single part
- **Regulated industries** (automotive, aerospace, defense) with material certification requirements
- **Applications** where reduced safety margins are desired for weight optimization
---
## **6. International Standards & Equivalents**
### **Primary Standards:**
| Standard | Designation | Governing Specification | Notes |
|----------|-------------|-------------------------|-------|
| **SAE/AISI** | **5135H** | SAE J404, J412, J1268 | Primary specification |
| **UNS** | **G51351** | Unified Numbering System | Material identification |
| **ASTM** | - | A304 (Standard for H-Steel Bars) | Bar product specification |
| **AMS** | **AMS 2301** | - | Aircraft quality cleanliness |
### **Global H-Grade Equivalents:**
| Country/Region | Standard | H-Grade Equivalent | Hardness Comparison |
|----------------|----------|-------------------|---------------------|
| **International (ISO)** | ISO 683-11 | **34Cr4H** | Type 1.7035H |
| **Europe (EN)** | EN 10083-3 | **34Cr4H** | Designation 1.7035H |
| **Germany** | DIN 17211 | **34Cr4H** | Direct equivalent |
| **Japan** | JIS G4052 | **SCr440H** | Similar hardenability control |
| **China** | GB/T 5216 | **35CrH** | Chinese H-grade equivalent |
| **France** | NF A35-556 | **35C4H** | French H-grade specification |
| **United Kingdom** | BS 970 | **530M40H** | British H-grade |
### **Quality & Processing Standards:**
- **Hardenability Testing:** SAE J1268 (Standard Method for Jominy Test)
- **Material Cleanliness:** ASTM E45 (Method D), AMS 2301 (Aircraft Quality)
- **Heat Treatment:** AMS 2759 (Pyrometry), CQI-9 (Automotive)
- **Traceability:** EN 10204 3.1/3.2 Certification required
- **Non-Destructive Testing:** ASTM E1444 (MPI), A388 (UT), E709 (MPI Standard)
---
## **7. Manufacturing & Processing Guidelines**
### **Heat Treatment Specifications:**
**Pre-machining Conditioning:**
- **Spheroidize Annealing:** 740-760°C, hold 6-8 hours, furnace cool to 650°C at ≤8°C/hour
- **Result:** 179-197 HB, optimal for heavy machining operations
- **Alternative:** Subcritical anneal at 680-700°C for stress relief without significant softening
**Through-Hardening Process (Recommended):**
1. **Pre-heat:** 650-700°C (essential for sections >50mm to minimize distortion)
2. **Austenitize:** 850±5°C, soak 30 minutes per inch of thickness (minimum 30 minutes)
3. **Quench:** Fast oil at 40-60°C, agitation to achieve H=0.50-0.80
4. **Tempering:** Begin when parts reach 50-80°C, hold 2+ hours per inch
5. **Cooling:** Air cool after tempering; rapid cool through 350-575°C recommended
**Alternative Heat Treatment Methods:**
- **Martempering:** Quench into hot oil at 180-220°C, hold to equalize, air cool (reduces distortion)
- **Austempering:** Quench into salt bath at 290-330°C, hold to transformation, air cool (improves toughness)
### **Machining Parameters:**
- **Optimal Condition:** Spheroidize annealed (179-197 HB)
- **Turning Speed (Carbide):** 35-55 m/min for finishing, 25-40 m/min for roughing
- **Feed Rate:** 0.10-0.25 mm/rev for finishing, 0.30-0.50 mm/rev for roughing
- **Depth of Cut:** Up to 4.0 mm for roughing, 0.3-0.8 mm for finishing
- **Tool Material:** Carbide grades C2-C6 for production, premium cobalt HSS for toolroom
- **Tool Geometry:** Positive rake (5-8°), sharp cutting edges, chip breakers for stringy chips
- **Coolant:** Water-soluble emulsion (5-10%) or neat oil for difficult operations
### **Grinding After Heat Treatment:**
- **Wheel Selection:** Aluminum oxide (A46-J-V) or CBN for hardened material
- **Cutting Fluid:** Water-soluble emulsion with rust inhibitor
- **In-feed:** 0.005-0.020 mm per pass for finishing
- **Spark-out:** 2-4 passes with no infeed for dimensional stability
- **Caution:** Avoid grinding burns; monitor wheel sharpness and coolant flow
### **Welding (Restricted Applications Only):**
- **Pre-heat Requirement:** 300-350°C minimum
- **Interpass Temperature:** 300-350°C
- **Post-weld Heat Treatment:** Full re-austenitize, quench, and temper recommended
- **Alternative:** Stress relief at 620-650°C for 2 hours per inch if full HT not possible
- **Electrode Type:** Low-hydrogen (E11018-D2 or equivalent)
- **Critical Restriction:** Weld-affected zones will have different properties; not recommended for highly stressed areas
---
## **8. Quality Assurance & Certification**
### **H-Grade Certification Requirements:**
**Mandatory Documentation:**
1. **Hardenability Test Report:** Complete Jominy curve with actual test data points
2. **Chemical Analysis Certificate:** Full elemental analysis per heat/lot
3. **Material Test Certificate:** EN 10204 3.1 or 3.2 format
4. **Heat Treat Response Data:** For critical applications (optional but recommended)
**Statistical Quality Requirements:**
- **Hardenability Compliance:** 100% of heats must fall within SAE J1268 specified bands
- **Process Capability:** Cp ≥ 1.33 for all critical mechanical properties
- **Lot-to-Lot Consistency:** ≤2.0 HRC variation in equivalent heat treatment conditions
- **Property Uniformity:** ≤3.0 HRC variation within same heat treated lot
### **Inspection & Testing Protocol:**
**Per Heat/Lot Testing:**
- **Chemical Analysis:** Spectrochemical per ASTM A751 (3 samples minimum)
- **Hardenability Test:** One Jominy test per heat (additional for heats >50 tons)
- **Mechanical Properties:** Tensile and impact tests per specified sampling plan
- **Microcleanliness:** Per ASTM E45 Method D (typically specified for critical applications)
**Additional Testing (Customer Specification):**
- **Grain Size Determination:** ASTM E112, typically 6-8 required
- **Decarburization Measurement:** ASTM E1077, typically ≤0.25mm total per side
- **Macroetch Examination:** ASTM E340 for internal quality assessment
- **Non-Destructive Testing:** UT per ASTM A388, MPI per ASTM E1444/E709
### **Traceability System:**
- **Heat Identification:** Permanently marked on each piece or bundle
- **Process History:** Complete documentation of all thermal and mechanical processing
- **Test Coupon Retention:** Representative samples retained per quality plan
- **Certification Chain:** Full traceability from melt to finished product
---
## **9. Design Engineering Advantages**
### **Predictable Performance Characteristics:**
**Hardness Gradient Prediction Model (for 75mm diameter bar):**
| Distance from Surface | Predicted Hardness (HRC) after 450°C temper | Allowable Design Range | Strength Equivalent |
|-----------------------|---------------------------------------------|------------------------|---------------------|
| 0 mm (surface) | 37.5 | 36.0-39.0 | 1280 MPa |
| 9.4 mm (1/4 radius) | 36.9 | 35.4-38.4 | 1255 MPa |
| 18.8 mm (1/2 radius) | 36.3 | 34.8-37.8 | 1230 MPa |
| 28.1 mm (3/4 radius) | 35.7 | 34.2-37.2 | 1205 MPa |
| 37.5 mm (center) | 35.1 | 33.6-36.6 | 1180 MPa |
### **Fatigue Design Values (R=-1, polished):**
- **Endurance Limit Base Value:** 0.50 × Tensile Strength (at 10⁷ cycles)
- **Surface Finish Factor (ground):** 0.90-0.95
- **Size Factor (diameter correction):** 0.85 for 50mm, 0.80 for 75mm, 0.75 for 100mm
- **Reliability Factor:** 0.814 for 99% reliability, 0.752 for 99.9% reliability
- **Notch Sensitivity Index (q):** 0.82-0.87 for typical notch geometries
- **Calculated Design Endurance Limit:** 520-580 MPa at 38 HRC (tempered at 450°C)
### **Allowable Stresses (Safety Factors per Industry Standards):**
| Loading Condition | Allowable Stress (38 HRC) | Safety Factor | Applicable Standard |
|-------------------|---------------------------|---------------|---------------------|
| **Static Tension** | 600 MPa | 1.67 on yield | ASME B&PV, AISC |
| **Static Shear** | 345 MPa | 1.67 on yield | AISC, DIN |
| **Static Bearing** | 900 MPa | 2.00 on yield | AISC |
| **Fully Reversed Bending** | 260 MPa | 2.00 on endurance | FKM, DIN |
| **Fully Reversed Torsion** | 150 MPa | 2.00 on endurance | FKM |
### **Section Size Design Guidelines:**
| Diameter (mm) | Expected Hardness Gradient (ΔHRC) | Recommended Applications | Heat Treatment Notes |
|---------------|-----------------------------------|--------------------------|---------------------|
| **≤25** | ≤1.5 | Precision gears, high-speed shafts | Uniform hardening achievable |
| **25-50** | ≤3.0 | General machinery shafts, gears | Slight center softening acceptable |
| **50-75** | ≤5.0 | Heavy equipment shafts, large gears | Moderate gradient, design accordingly |
| **75-100** | ≤7.0 | Large axles, rolling mill rolls | Significant gradient, core properties important |
| **100-125** | ≤10.0 | Special applications only | Limited to non-critical areas or surface hardening |
---
## **10. Comparison with Standard 5135 & Other H-Grades**
### **Key Differentiators from Standard 5135:**
| Parameter | 5135H | Standard 5135 | Impact on Design & Manufacturing |
|-----------|-------|---------------|----------------------------------|
| **Chemistry Control** | Tight ranges (±0.025% C) | Standard SAE ranges | Enables precise property prediction |
| **Hardenability** | Guaranteed SAE J1268 bands | Variable by heat | Eliminates need for conservative safety factors |
| **Cost Premium** | 15-20% higher | Baseline | Justified by reduced testing and improved yield |
| **Testing Required** | Minimal (certified) | Extensive per heat/lot | Significant cost and time savings |
| **Design Allowables** | Can use mean values | Must use minimum values | Enables weight optimization (5-15% reduction) |
| **Production Consistency** | Excellent (Cp ≥ 1.33) | Variable (Cp ≈ 0.8-1.2) | Reduces scrap/rework, improves process yield |
| **Traceability** | Full heat-to-heat with certs | Basic heat identification | Essential for regulated industries |
### **Economic Justification Analysis:**
- **Material Cost Increase:** +15-20%
- **Reduced Testing Cost:** -30-50% (eliminates extensive lot testing)
- **Lower Scrap/Rework:** -20-40% (consistent response to heat treatment)
- **Improved Process Yield:** +8-15% (predictable dimensional changes)
- **Reduced Safety Margins:** Enables 5-15% weight reduction
- **Reduced Inventory:** Smaller safety stocks possible
- **Total Cost Impact:** Typically neutral or positive in high-volume applications
### **Comparison with Other H-Grades in 51xx Series:**
| Grade | Carbon Range | DI Range (mm) | Relative Cost | Optimal Application Size |
|-------|--------------|---------------|---------------|--------------------------|
| **5130H** | 0.27-0.33 | 55-70 | 1.00 | ≤60 mm diameter |
| **5132H** | 0.29-0.34 | 60-75 | 1.05 | 50-75 mm diameter |
| **5135H** | 0.32-0.37 | 70-85 | 1.10 | 60-90 mm diameter |
| **5140H** | 0.38-0.43 | 75-95 | 1.15 | 75-100+ mm diameter |
---
## **11. Technical Performance Data**
### **Fatigue Characteristics (Detailed):**
- **Rotating Bending Endurance (10⁷ cycles):** 530-590 MPa at 38 HRC
- **Fatigue Ratio Development:** Increases with tensile strength up to ~0.52 at 1500 MPa
- **Fatigue Crack Growth Threshold (ΔKth):** 7-9 MPa√m (R=0.1)
- **Paris Law Constants:** C = 6.5×10⁻¹², n = 3.3 (da/dN in m/cycle, ΔK in MPa√m)
- **Notch Fatigue Strength Reduction:** Kf = 1.8-2.4 for sharp notches (Kt = 3)
- **Surface Treatment Effects:** Shot peening improves fatigue limit by 30-45%
### **Wear Performance Metrics:**
- **Abrasive Wear Resistance (relative to 1020 steel):** 4.0-4.5× at 38 HRC
- **Adhesive Wear (scoring resistance):** Good with EP lubricants, limited without
- **Contact Fatigue (pitting) Life:** L₁₀ > 2×10⁷ cycles at 1.8 GPa contact pressure
- **Break-in Characteristics:** Optimal with surface finish 0.8-1.6 μm Ra, 10-30% oil retention
- **Gallling Resistance:** Moderate; requires proper lubrication and surface treatment
### **Temperature Performance Limits:**
- **Maximum Continuous Service:** 300°C (570°F) without significant property loss
- **Short-term Exposure Limit:** 500°C (930°F) for <100 hours
- **Temper Resistance:** Good up to 400°C (750°F) for 1000+ hours
- **Cryogenic Suitability:** Down to -40°C (-40°F) with proper heat treatment
- **Thermal Fatigue Resistance:** Moderate; ΔT ≤ 250°C recommended to avoid cracking
- **Creep Resistance:** Limited; not recommended for sustained high-temperature service
### **Corrosion Behavior & Protection:**
- **General Corrosion Rate:** 0.08-0.25 mm/year in industrial atmosphere
- **Pitting Resistance Equivalent (PRE):** ~10.5 (limited corrosion resistance)
- **Stress Corrosion Threshold (K₁SCC):** 22-28 MPa√m in 3.5% NaCl solution
- **Hydrogen Embrittlement Susceptibility:** Moderate; baking required after plating
- **Recommended Coatings:** Zinc plating (with chromate), cadmium plating, phosphate+oil, DLC for wear
- **Painting Compatibility:** Excellent with proper surface preparation (sandblasting recommended)
---
## **12. Special Considerations & Technical Notes**
### **Processing Limitations & Constraints:**
1. **Maximum Effective Section:** ~100 mm diameter for through-hardening in oil with strong agitation
2. **Distortion Control:** Requires careful fixturing, especially for asymmetrical parts
3. **Decarburization Sensitivity:** Protective atmosphere or packaging required during heat treatment
4. **Grinding Limitations:** Avoid excessive heat input to prevent tempering or re-hardening
5. **Size Effect:** Properties in very large sections (>125mm) may not meet typical expectations
### **Metallurgical Considerations:**
- **Temper Embrittlement Range:** 350-575°C (660-1070°F) - rapid cooling through this range essential
- **Retained Austenite:** Typically <10% after quenching, reduced to <5% after proper tempering
- **Tempering Response:** Secondary hardening peak observed around 500-550°C from alloy carbide precipitation
- **Grain Growth Control:** Maximum recommended austenitizing temperature 880°C to prevent excessive grain growth
- **Hardenability Band Interpretation:** Actual production heats typically cluster in middle 60% of allowed band
### **Quality Assurance Specifics:**
- **Hardenability Test Frequency:** One test per heat, plus one per 50 tons for large heats
- **Test Coupon Location:** From center of billet or bloom for representative results
- **Statistical Process Control:** Required at steel mill for H-grade production
- **Supplier Qualification:** Requires certified melting facilities with ladle refining capability
- **Lot Acceptance:** Based on hardenability certification, not just chemistry compliance
### **Design for Manufacturing Considerations:**
- **Allow for Distortion:** Typical growth 0.1-0.3% during heat treatment
- **Grinding Allowance:** 0.2-0.5 mm per side minimum after heat treatment
- **Stress Relief:** Recommended after heavy machining before final heat treatment
- **Symmetry:** Design symmetrical parts where possible to minimize distortion
- **Section Transitions:** Use generous radii (R ≥ 0.5× thickness change)
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## **13. Storage, Handling & Documentation**
### **Material Identification & Traceability:**
- **Heat Number Marking:** Permanent stamping or tagging on each piece
- **Hardenability Code:** Identification of actual Jominy test results
- **Certification Package:** EN 10204 3.1 or 3.2 certificate with each shipment
- **Test Reports:** Complete mechanical, chemical, and hardenability data
- **Material Safety Data Sheet:** Provided for handling and disposal guidance
### **Storage & Preservation Requirements:**
- **Storage Environment:** Dry, temperature-controlled warehouse (RH < 60%)
- **Rust Prevention:** VCI paper wrapping or rust preventive coating for long-term storage
- **Stacking:** Proper support to prevent bending or distortion; not directly on concrete
- **Shelf Life:** 12 months recommended maximum with periodic inspection
- **Revalidation:** Required after extended storage (>12 months) or environmental exposure
- **Handling:** Use non-marring lifting devices; avoid impact damage to machined surfaces
### **Documentation Requirements (Regulated Industries):**
1. **Material Certificate:** Full chemistry, hardenability, mechanical properties
2. **Heat Treatment Records:** For any supplied in heat treated condition
3. **Non-Destructive Testing Reports:** UT, MPI, or other as specified
4. **Statistical Process Control Data:** For high-volume production applications
5. **Traceability Chain:** Complete documentation from melt to finished product
6. **Compliance Statements:** REACH, RoHS, conflict minerals as required
7. **First Article Inspection Reports:** For initial production lots
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**Technical Significance:** AISI 5135H represents the optimal balance in the 51xx H-grade series for applications requiring reliable through-hardening in medium to large sections (60-100mm diameter). Its guaranteed hardenability provides engineering and manufacturing benefits that often justify the material cost premium through reduced testing, improved process yield, and optimized designs. Particularly valuable in regulated industries and safety-critical applications, 5135H enables manufacturers to achieve consistent quality while maintaining economic viability.
**Revision:** 1.2
**Date:** October 2023
**Disclaimer:** This technical specification describes AISI 5135H material produced to SAE J1268 standards. While hardenability is guaranteed within specified bands, actual mechanical properties in finished components depend on specific heat treatment parameters, section size, machining history, and other processing variables. Designers should always verify critical properties through application-specific testing and consult with qualified metallurgical engineers for safety-critical applications. H-grade certification ensures material consistency but does not eliminate the need for proper manufacturing process control and quality assurance.
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AISI 5135H Steel Specification
Dimensions
Size：
Diameter 20-1000 mm Length <4117 mm
Size:We can customized as required
Standard：
Per your request or drawing
We can customized as required
Properties（Theoretical）
Chemical Composition
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AISI 5135H Steel Properties
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Applications of AISI 5135H Steel Flange
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Chemical Identifiers AISI 5135H Steel Flange
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Packing of AISI 5135H Steel Flange
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Standard Packing:
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Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 588 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition
