Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel

Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel Product Information -:- For detailed product information, please contact sales. -: Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel Synonyms -:- For detailed product information, please contact sales. -:

Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel Product Information -:- For detailed product information, please contact sales. -: # Product Datasheet: Latrobe Nitralloy® 135 Modified VAC-ARC (1.5" to 3.0") Premium Nitriding Steel ## 1. Product Overview **Latrobe Nitralloy® 135 Modified VAC-ARC** in the 1.5" to 3.0" (38-76 mm) section range represents the most robust variant of this premium nitriding steel, specifically engineered for **extra-large, heavily loaded components** requiring both deep hardenability and exceptional surface properties. Manufactured through advanced **Vacuum Arc Remelting (VAC-ARC)** technology, this material is optimized to deliver uniform mechanical properties through thick sections while maintaining superior nitriding response. This grade is specifically designed for applications where conventional nitriding steels cannot provide adequate core strength or dimensional stability in large cross-sections, making it indispensable for critical power generation, heavy industrial, and large aerospace components. ## 2. Key Advantages & Characteristics - **Exceptional Deep Section Hardenability**: Specifically formulated to maintain uniform properties in sections from 1.5" to 3.0" (38-76 mm) thickness - **Superior Nitriding Performance in Thick Sections**: Maintains excellent nitride formation capability despite increased alloy content for hardenability - **Minimal Property Gradient**: Reduced hardness drop-off from surface to center in large sections compared to standard grades - **Enhanced Dimensional Stability**: Predictable and minimal distortion during both quenching and nitriding processes for large components - **Optimized Toughness-Strength Balance**: Maintains good impact resistance even at high strength levels in thick sections - **Superior Steel Cleanliness**: VAC-ARC process ensures extremely low inclusion content critical for large forging integrity - **Consistent Response Through Thickness**: Uniform nitriding and hardening response across entire cross-section - **Reduced Susceptibility to Quenching Cracks**: Modified chemistry and processing minimize internal stresses during hardening ## 3. Chemical Composition (Modified for 1.5"-3.0" Sections) ### 3.1 Enhanced Composition (wt.%) | Element | Content Range | Typical Value | Metallurgical Function for Thick Sections | |---------|--------------|---------------|------------------------------------------| | Carbon (C) | 0.40-0.48 | 0.44 | Increased for core strength in thick sections | | Aluminum (Al) | 0.95-1.25 | 1.10 | Enhanced for sustained nitride formation in deep cases | | Chromium (Cr) | 1.50-1.90 | 1.70 | Increased for improved hardenability and nitride stability | | Molybdenum (Mo) | 0.35-0.55 | 0.45 | Enhanced for through-thickness hardening and temper resistance | | Vanadium (V) | 0.15-0.25 | 0.20 | Increased for grain refinement in slow-cooling thick sections | | Nickel (Ni) | 0.80-1.20 | 1.00 | **New Addition**: Significantly improves core toughness in thick sections | | Manganese (Mn) | 0.60-0.90 | 0.75 | Increased for enhanced hardenability in large sections | | Silicon (Si) | 0.25-0.45 | 0.35 | Moderate increase for solid solution strengthening | | Sulfur (S) | ≤0.008 | 0.004 | Ultra-low to maximize transverse properties | | Phosphorus (P) | ≤0.012 | 0.008 | Strict impurity control | | Iron (Fe) | Balance | Balance | Matrix | ### 3.2 VAC-ARC Process Enhancements for Large Sections - **Oxygen Content**: ≤10 ppm (typically 4-7 ppm) for improved fatigue resistance - **Hydrogen Content**: ≤1.5 ppm to minimize hydrogen embrittlement risk - **Macro-Segregation Control**: Advanced solidification control for uniform chemistry in large ingots - **Inclusion Morphology Control**: Spheroidized inclusions to minimize stress concentrations - **Grain Structure**: Uniform ASTM 5-7 throughout large sections ### 3.3 Key Modifications vs. Standard 135 - **Nickel Addition**: 0.8-1.2% Ni for dramatically improved core toughness in thick sections - **Higher Carbon**: Increased to 0.40-0.48% for maintaining core strength at depth - **Balanced Aluminum**: Optimized for deep nitriding without excessive grain coarsening - **Enhanced Molybdenum**: For improved hardenability and tempering resistance - **Vanadium Increase**: For grain control in slow-cooling large sections ## 4. Manufacturing Process for Large Sections ### 4.1 Specialized VAC-ARC Processing ``` 1. INGOT PRODUCTION FOR LARGE SECTIONS • Oversized electrode preparation (400-600mm diameter) • Extended VAC-ARC cycle with controlled melt rate (100-200 kg/hr) • Advanced solidification control (0.5-2.0°C/min cooling rate) • Segregation minimization through thermal management • Ingot sizes: 600-1000mm diameter, 2000-4000mm length 2. THERMOMECHANICAL PROCESSING • Extended homogenization: 1180-1220°C for 8-16 hours • Multiple forging/heating cycles with controlled reductions • Cross-forging techniques for uniform grain structure • Intermediate annealing for recrystallization • Final shaping with proper grain flow orientation 3. HEAT TREATMENT PREPARATION • Spheroidize annealing for optimal machinability • Controlled cooling to prevent carbide networks • Extensive non-destructive testing (UT, MT, PT) ``` ### 4.2 Quality Control for Large Sections | Parameter | Specification | Test Method | Section Size Application | |-----------|---------------|-------------|-------------------------| | Ultrasonic Quality | AMS 2301, Class 1 | Full volume scan | All sections 1.5"-3.0" | | Macro-Etch Uniformity | ASTM E381, Uniform | Multiple locations | Center, mid-radius, surface | | Hardenability Verification | ASTM A255, Extended | Jominy to 3" equivalent | Validated for 3" ruling section | | Inclusion Rating | ASTM E45, Plate 1 ≤0.3 | Surface, mid, center | Stricter than standard | | Grain Size Consistency | ASTM 5-7 throughout | Multiple sections | Verified at 3" depth | ## 5. Physical & Mechanical Properties ### 5.1 Base Material Properties (Annealed Condition) | Property | 1.5" Section | 2.0" Section | 3.0" Section | Test Standard | |----------|--------------|--------------|--------------|---------------| | Hardness | 229-285 HB | 235-293 HB | 241-302 HB | ASTM E10 | | Tensile Strength | 795-965 MPa | 825-1000 MPa | 860-1035 MPa | ASTM E8 | | Yield Strength (0.2%) | 585-760 MPa | 620-795 MPa | 655-825 MPa | ASTM E8 | | Elongation | 15-20% | 14-18% | 13-17% | ASTM E8 | | Reduction of Area | 35-45% | 32-42% | 30-40% | ASTM E8 | ### 5.2 Heat Treated Core Properties (Before Nitriding) | Property | 1.5" Section | 2.0" Section | 3.0" Section | Heat Treatment | |----------|--------------|--------------|--------------|----------------| | Core Hardness | 34-40 HRC | 32-38 HRC | 30-36 HRC | Oil quenched & tempered | | Ultimate Tensile | 1240-1480 MPa | 1170-1380 MPa | 1100-1310 MPa | Center of section | | Yield Strength | 1100-1310 MPa | 1030-1240 MPa | 965-1170 MPa | 0.2% offset | | Impact Energy (Charpy) | 40-55 J | 35-50 J | 30-45 J | Room temperature | | Fracture Toughness (K₁C) | 70-85 MPa√m | 65-80 MPa√m | 60-75 MPa√m | ASTM E1820 | ### 5.3 Through-Thickness Hardness Profile (Jominy Equivalent) | Distance from Surface | Hardness (HRC) | Hardness Drop from Surface | |------------------------|----------------|----------------------------| | Surface (Quenched) | 52-56 HRC | Baseline | | 0.5" Depth | 48-52 HRC | 4-6 HRC drop | | 1.0" Depth | 44-48 HRC | 8-10 HRC drop | | 1.5" Depth | 40-44 HRC | 12-14 HRC drop | | 2.0" Depth | 36-40 HRC | 16-18 HRC drop | | 2.5" Depth | 33-37 HRC | 19-21 HRC drop | | Center (3.0") | 30-34 HRC | 22-24 HRC drop | ### 5.4 Nitrided Surface Properties for Large Sections | Property | 1.5" Section | 2.0"-3.0" Section | Nitriding Conditions | |----------|--------------|-------------------|---------------------| | Surface Hardness | 67-73 HRC (925-1100 HV) | 66-72 HRC (900-1075 HV) | Gas, 510-525°C, 50-80h | | Effective Case Depth | 0.50-1.00 mm | 0.45-0.90 mm | At 500 HV (50 HRC) | | Case Depth Consistency | ±0.08 mm | ±0.10 mm | Through-thickness variation | | White Layer Control | 15-30 μm | 15-35 μm | Adjustable via process | | Surface Compressive Stress | -550 to -950 MPa | -500 to -900 MPa | Maximum at surface | ### 5.5 Thermal & Physical Properties | Property | Value | Conditions | Importance for Large Sections | |----------|-------|-----------|-------------------------------| | Thermal Conductivity | 38.5 W/m·K | 20°C | Affects cooling uniformity | | Specific Heat | 470 J/kg·K | 20°C | Heat treatment energy requirements | | Thermal Expansion | 11.8×10⁻⁶/°C | 20-100°C | Dimensional change prediction | | Thermal Diffusivity | 10.5 mm²/s | 20°C | Quenching response | | Ac₁ Temperature | 750°C | Lower critical | Heat treatment planning | | Ac₃ Temperature | 825°C | Upper critical | Austenitizing temperature | | Quench Severity (H-value) | 0.35-0.45 | Oil quench | For thick section hardening | ## 6. Heat Treatment Guidelines for Large Sections ### 6.1 Pre-Nitriding Heat Treatment for 3.0" Sections ``` FOR 3.0" (76mm) SECTIONS: 1. PREHEATING (Critical for Large Sections) • Stage 1: 350-400°C for 1-2 hours • Stage 2: 650-700°C for 2-3 hours • Purpose: Minimize thermal shock and stress 2. AUSTENITIZING • Temperature: 860-885°C (1580-1625°F) • Soak Time: 1.5-2.0 hours per inch of thickness • Atmosphere: Protective or vacuum • Uniformity: Critical - monitor multiple locations 3. QUENCHING • Medium: Fast oil with high agitation • Temperature: 40-60°C (100-140°F) • Agitation: Very vigorous, directional flow • Monitoring: Center temperature vs. time critical 4. TEMPERING (DOUBLE RECOMMENDED) • Temperature: 580-620°C (1075-1150°F) • Time: 3-4 hours per inch minimum • Cycle: Temper twice at same temperature • Cooling: Slow furnace cool after tempering 5. STRESS RELIEVING (MANDATORY) • Temperature: 620-650°C (1150-1200°F) • Time: 4-6 hours • Purpose: Maximize dimensional stability before nitriding ``` ### 6.2 Nitriding Process for Large Sections ``` GAS NITRIDING OPTIMIZED FOR THICK SECTIONS: • Pre-cleaning: Critical - vapor degrease + mechanical clean • Temperature: 515-530°C (960-985°F) - higher for deeper diffusion • Time: 60-120 hours for 0.6-1.0 mm case depth • Atmosphere: Two-stage process with varying NH₃ concentration • Cooling: Controlled slow cool (≤30°C/hour) to 300°C • Post-nitriding Temper: 300-350°C for 4-8 hours to relieve stresses PLASMA NITRIDING ADVANTAGES FOR LARGE PARTS: • Temperature Uniformity: Excellent for complex geometries • Process Control: Precise white layer management • Environment: No ammonia handling concerns • Case Consistency: Excellent for deep cases ``` ### 6.3 Special Considerations for Large Components - **Fixturing**: Special racks/supports to minimize distortion - **Temperature Monitoring**: Multiple thermocouples at different depths - **Quench Delay**: Minimize transfer time from furnace to quench - **Post-nitriding Machining**: Allow for final dimensional adjustment - **Non-destructive Testing**: Extensive UT and MT after all thermal processes ## 7. International Standards & Specifications ### 7.1 Primary Specifications for Large Sections | Standard | Designation | Application Range | Notes | |----------|-------------|-------------------|-------| | AMS 6472 (Modified) | Nitralloy 135 Enhanced | 1.5"-3.0" sections | Special procurement specification | | ASTM A355 (Grade 135M) | Modified 135 | Thick sections | Custom grade specification | | Latrobe Proprietary | N-135-3.0 | 1.5"-3.0" exclusive | Enhanced for thick sections | | AMS 2301 | Special Premium Quality | All large sections | With extended testing requirements | | AMS 2759/5 | Class D Nitriding | Heavy section process | Special procedures for thick parts | ### 7.2 Industry-Specific Standards | Industry | Standard | Application | Section Size | |----------|----------|------------|--------------| | Aerospace | AMS-H-6875B | Heavy section heat treatment | Up to 3.0" | | Power Generation | ASTM A668 Class F | Heavy forgings | 2.0"-3.0" | | Marine | MIL-S-22698 | Large shafting | 2.0"-4.0" | | Oil & Gas | API 6A/17D | Wellhead components | 2.0"-3.0" | | Nuclear | RCC-M M2131 | Large components | With restrictions | ### 7.3 Global Equivalents for Thick Sections | Country | Standard | Equivalent Grade | Maximum Section | |---------|----------|-----------------|-----------------| | Germany | DIN 17211 | 34CrAlNi7 (enhanced) | 80 mm | | Japan | JIS G4202 | SACM 645 (modified) | 70 mm | | France | NF A35-556 | 35NCD16 (modified) | 75 mm | | UK | BS 970 | 905M39 (enhanced) | 76 mm | | International | ISO 683-10 | 34CrAlNi7-10 | 80 mm | ## 8. Product Applications ### 8.1 Power Generation (Primary Application) - **Large Turbine Shafts**: Steam turbine rotors (2.5"-3.0" diameters), generator shafts - **Hydroelectric Components**: Turbine shafts (2.0"-3.0"), gate mechanism components - **Gas Turbine Parts**: Compressor shafts, turbine discs, bearing housings - **Nuclear Components**: Control rod drive mechanisms, pump shafts (non-active) - **Wind Turbine**: Main shaft sections, gearbox components for multi-MW turbines ### 8.2 Heavy Industrial & Marine - **Large Gear Blanks**: Mining equipment gears (2.0"-3.0" face width), mill pinions - **Marine Propulsion**: Propeller shafts (2.5"-3.0"), stern tubes, rudder stocks - **Crane Components**: Hoist shafts, boom pivot pins, slewing rings - **Press Components**: Crankshafts, eccentric shafts for large forming presses - **Rolling Mill**: Backup roll shafts, spindle couplings ### 8.3 Aerospace & Defense (Large Components) - **Large Aircraft**: Main landing gear components, wing attachment fittings - **Helicopter**: Main rotor shafts (2.0"-2.5"), transmission input/output shafts - **Rocket/Missile**: Large launch tube components, motor casing fittings - **Naval Systems**: Large gun mount components, periscope mechanisms ### 8.4 Specialized Heavy Equipment - **Oil & Gas**: Large Christmas tree components, blowout preventer parts - **Mining**: Dragline components, shovel dipper handles, crusher main shafts - **Chemical Processing**: Large mixer shafts, reactor agitators - **Paper Manufacturing**: Large dryer rolls, calendar stack components ## 9. Machining & Processing of Large Sections ### 9.1 Machining Recommendations for Thick Sections | Operation | 1.5"-2.0" Sections | 2.0"-3.0" Sections | Special Considerations | |-----------|-------------------|-------------------|------------------------| | Turning | Speed: 60-100 m/min | Speed: 55-90 m/min | Increased rigidity required | | Feed | 0.20-0.35 mm/rev | 0.18-0.30 mm/rev | Lower feeds for heavy cuts | | Milling | Speed: 70-120 m/min | Speed: 65-110 m/min | Climb milling preferred | | Feed/tooth | 0.12-0.22 mm | 0.10-0.18 mm | Reduced for tool life | | Drilling | Speed: 20-35 m/min | Speed: 18-30 m/min | Peck drilling required | | Feed | 0.12-0.25 mm/rev | 0.10-0.20 mm/rev | Frequent chip clearing | ### 9.2 Tooling Recommendations - **Insert Grades**: Carbide grades with high edge strength (P30-P40 equivalent) - **Tool Geometry**: Positive rake for reduced cutting forces - **Coolant Application**: High-pressure through-tool coolant essential - **Machine Requirements**: Rigid machines with high torque capacity ### 9.3 Special Processing Considerations - **Stress Equalization**: Multiple stress relief cycles during rough machining - **Balancing**: Dynamic balancing of large rotating components - **NDT Integration**: Regular inspection during machining process - **Temperature Control**: Avoid localized heating during machining - **Handling Equipment**: Proper lifting and support to prevent distortion ## 10. Performance Data & Comparative Analysis ### 10.1 Hardenability Comparison for Thick Sections | Material | 1.5" Center HRC | 2.0" Center HRC | 3.0" Center HRC | Hardenability Factor | |----------|-----------------|-----------------|-----------------|---------------------| | Nitralloy® 135 Modified | 34-40 | 32-38 | 30-36 | Excellent | | Standard 135 | 30-36 | 27-33 | 24-30 | Good | | AISI 4340 | 33-39 | 30-36 | 27-33 | Very Good | | Nitralloy N | 28-34 | 25-31 | 22-28 | Moderate | ### 10.2 Toughness Comparison in Thick Sections | Property | Nitralloy® 135 Modified | AISI 4340 | Standard 135 | Advantage | |----------|-------------------------|-----------|--------------|-----------| | Charpy Impact (1.5") | 40-55 J | 35-50 J | 25-40 J | 15-30% better | | Fracture Toughness | 70-85 MPa√m | 65-80 MPa√m | 50-65 MPa√m | 20-40% better | | Transition Temperature | -40°C | -30°C | -20°C | Better low-temp performance | | Fatigue Crack Growth | Slow | Moderate | Moderate | Superior resistance | ### 10.3 Nitriding Performance in Large Sections | Parameter | 1.5"-2.0" Performance | 2.0"-3.0" Performance | Key Advantage | |-----------|----------------------|----------------------|---------------| | Case Depth Uniformity | ±0.08 mm | ±0.10 mm | Excellent for size | | Surface Hardness Drop | 1-2 HRC from thin section | 2-3 HRC from thin section | Minimal reduction | | White Layer Consistency | Excellent | Very Good | Controlled growth | | Process Time Increase | +20-30% vs. 1" | +40-60% vs. 1" | Predictable scaling | ### 10.4 Economic & Life Cycle Advantages - **Service Life**: 2-4× longer than standard steels in similar applications - **Maintenance Intervals**: Extended by 50-100% - **Failure Reduction**: Significant decrease in catastrophic failures - **Total Cost**: Lower life cycle cost despite higher initial material cost - **Availability**: Reduced downtime for replacement/repair ## 11. Quality Assurance for Large Sections ### 11.1 Extended Testing Requirements | Test | Frequency | Locations Tested | Acceptance Criteria | |------|-----------|------------------|-------------------| | Chemical Analysis | Each heat + product testing | Top, middle, bottom of ingot | Uniformity requirements | | Ultrasonic Testing | 100% at multiple stages | Full volume scanning | AMS 2301 Class 1 | | Macro-Etch | Each forging/bar | Multiple transverse sections | Uniform grain flow | | Mechanical Properties | Each heat + product testing | Surface, mid-radius, center | All meet specifications | | Hardenability Verification | Each heat | Extended Jominy (to 4" equivalent) | Meet 3.0" ruling section | ### 11.2 Special Quality Documentation - **Triple Certification**: Heat, process, and product certification - **Extended Traceability**: Full pedigree from melt to finished component - **Process Data Logging**: Complete thermal process records - **Statistical Reporting**: Process capability analysis for critical parameters ### 11.3 Industry Certifications & Compliance - **AS9100 Rev D**: Aerospace quality management - **ISO 9001:2015**: Quality management systems - **NADCAP**: Heat treating and testing accreditation - **Nuclear Compliance**: For applicable applications - **Marine Certification**: ABS, DNV, Lloyd's Register ## 12. Technical Support & Design Guidelines ### 12.1 Design Recommendations for Large Nitrided Components - **Section Transitions**: Use generous radii (minimum 6× section change) - **Stress Concentration Factors**: Design for Kt ≤ 2.0 in critical areas - **Surface Finish Specification**: Ra 1.6-3.2 μm before nitriding for large parts - **Dimensional Allowances**: Include 0.002-0.004 in/in growth allowance for nitriding - **Masking Design**: Plan for selective nitriding from initial design phase - **Inspection Accessibility**: Design for post-nitriding inspection capability ### 12.2 Application Engineering Guidelines - **Load Analysis**: Complete FEA recommended for stress distribution - **Temperature Gradients**: Consider in design for large mass components - **Corrosion Protection**: Specify post-nitriding oxidation for all outdoor applications - **Lubrication Systems**: Design for adequate lubrication of nitrided surfaces - **Assembly Considerations**: Account for different thermal expansion in assemblies ### 12.3 Failure Prevention for Large Components - **Comprehensive NDT**: Implement multiple NDT methods during manufacturing - **Process Validation**: Full-scale process trials for first articles - **Stress Monitoring**: Consider embedded strain gauges for critical applications - **Regular Inspection**: Scheduled in-service inspection programs - **Failure Analysis**: Immediate investigation of any anomalies ### 12.4 Economic Justification for Large Applications - **Life Extension**: Typically 3-5× service life vs. conventional materials - **Reduced Maintenance**: Significantly lower maintenance frequency and cost - **Downtime Reduction**: Extended operation between maintenance cycles - **Warranty Considerations**: Often enables extended warranties - **Insurance Benefits**: May qualify for reduced insurance premiums --- ## Technical Notice The information contained in this datasheet represents typical values and characteristics for Latrobe Nitralloy® 135 Modified VAC-ARC steel in the 1.5" to 3.0" section range. Actual properties may vary depending on specific processing conditions, component geometry, and heat treatment parameters. For large section applications, consultation with Latrobe technical personnel is **mandatory** before specification and procurement. **Critical Safety Precautions for Large Components**: - Specialized handling equipment required due to weight - Enhanced safety protocols for heat treatment of large masses - Special considerations for ammonia handling in large nitriding operations - Comprehensive risk assessment for all processing steps **Document Control**: - Document: LAT-N135-3.0-DS-001 - Revision: 4.1 - Effective Date: [Current Date] - Supersedes: All previous large section specifications **Contact Information**: Latrobe Specialty Metals Large Components Division [Company Address] Technical Services: [Specialized Contact Number] Email: [LargeSection.Technical@Company.com] Website: [Company Website/LargeComponents] --- *Nitralloy® is a registered trademark of Latrobe Specialty Metals. This information is proprietary and confidential. Reproduction or distribution without written permission is prohibited. Large section material availability may be limited and subject to minimum order quantities and extended lead times. Consult factory for current availability, pricing, and technical support for large component applications.* -:- For detailed product information, please contact sales. -: Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel Specification Dimensions Size： Diameter 20-1000 mm Length <5328 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel -:- For detailed product information, please contact sales. -: Chemical Identifiers Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel -:- For detailed product information, please contact sales. -:

Packing of Latrobe Nitralloy® 135 Modified VAC-ARC, 1.5 to 3 in Premium Nitriding Steel -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel 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 1799 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