CS5 Hot Work Tool Steel Tube,Pipe (UNS T91905)

CS5 Hot Work Tool Steel Tube (UNS T91905) Product Information -:- For detailed product information, please contact sales. -: CS5 Hot Work Tool Steel Tube (UNS T91905) Synonyms -:- For detailed product information, please contact sales. -:

CS5 Hot Work Tool Steel (UNS T91905) Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: CS5 Hot Work Tool Steel (UNS T91905)** ## **Overview** **CS5** is a **medium-carbon, chromium-based hot work tool steel** designated as **UNS T91905**. Engineered for exceptional **high-temperature strength, thermal fatigue resistance, and toughness**, CS5 represents a specialized grade within the hot work steel family. It is designed to maintain hardness and resist deformation under sustained thermal cycling and mechanical stress, making it ideal for demanding hot forming applications. Compared to more common hot work grades like H13, CS5 offers a unique balance of properties optimized for specific high-stress environments in die casting, forging, and extrusion tooling. --- ## **Chemical Composition (Typical Weight %)** The composition is balanced for high-temperature stability, thermal conductivity, and hot hardness. | Element | Content (%) | Role in Hot Work Performance | | :--- | :--- | :--- | | **Carbon (C)** | 0.35 - 0.45 | Provides base hardness and strength; balanced to maintain toughness at high temperatures. | | **Chromium (Cr)** | 4.75 - 5.50 | Imparts oxidation resistance, hardenability, and hot hardness through carbide formation. | | **Molybdenum (Mo)** | 1.25 - 1.75 | Enhances high-temperature strength, creep resistance, and hardenability; prevents temper embrittlement. | | **Vanadium (V)** | 0.80 - 1.20 | Forms stable, hard vanadium carbides that resist coarsening at high temps; improves wear and thermal fatigue resistance. | | **Silicon (Si)** | 0.80 - 1.20 | Increases resistance to thermal fatigue (heat checking) and oxidation; enhances high-temperature strength. | | **Manganese (Mn)** | 0.20 - 0.50 | Aids hardenability and deoxidization. | | **Sulfur (S)** | ≤ 0.03 | - | | **Phosphorus (P)** | ≤ 0.03 | - | | **Iron (Fe)** | **Balance** | Base metal. | **Key Feature:** The combination of **chromium, molybdenum, and vanadium** provides a synergistic effect for retaining hardness and strength at elevated temperatures (500-600°C / 930-1110°F), while **silicon** specifically combats heat checking. --- ## **Physical & Mechanical Properties** *Properties are for material in the hardened and tempered condition (typical operating hardness).* | Property | Typical Value / Description | | :--- | :--- | | **Density** | 7.80 g/cm³ (0.282 lb/in³) | | **Hardness (Annealed)** | 200 - 230 HB | | **Hardness (Hardened & Tempered)** | **40 - 52 HRC** (Typically operated at 44-48 HRC for optimal toughness/strength balance) | | **Hot Hardness (at 550°C / 1020°F)** | **~35-40 HRC** (Excellent retention of hardness at elevated temperature) | | **Thermal Fatigue Resistance** | **Excellent.** High resistance to the initiation and propagation of heat-check cracks due to good thermal conductivity and toughness. | | **Toughness** | **Very Good.** Superior to many high-carbon cold work steels, crucial for withstanding thermal and mechanical shock in hot work applications. | | **Thermal Conductivity** | **~28 W/m·K at 20°C** (Improves at higher temperatures, aiding heat dissipation from the tool surface). | | **Coefficient of Thermal Expansion** | ~12.5 × 10⁻⁶/°C (20-500°C) | | **Machinability (Annealed)** | **Fair to Good** (~60% of 1% carbon steel). | | **Grindability** | **Fair.** Requires proper wheel selection and cooling. | --- ## **Heat Treatment Guidelines** Precise heat treatment is critical to develop CS5's high-temperature properties. | Process | Parameters | Purpose/Notes | | :--- | :--- | :--- | | **Annealing** | Heat to 845-870°C (1550-1600°F), slow furnace cool to 480°C (900°F) at ≤15°C/hr, then air cool. | Achieves ~215 HB for safe machining. | | **Stress Relieving** | 650-675°C (1200-1250°F) for 2 hrs, air cool. (After rough machining) | Reduces machining stresses. | | **Preheating** | **Double Preheat:** 1) 650°C (1200°F), 2) 850°C (1560°F). **Essential.** | Minimizes thermal shock and distortion. | | **Austenitizing** | **1000-1030°C (1830-1885°F).** Soak: 20-30 min/in. (Use protective atmosphere/vacuum) | Dissolves carbides for optimal alloying effect. | | **Quenching** | **Quench in still or forced air (preferred)** or oil for complex shapes. | Air quenching minimizes stress; oil for maximum hardness in thick sections. | | **Tempering** | **Double or Triple Temper immediately.** **540-600°C (1000-1110°F)** for 2+ hrs each. | **Mandatory** to achieve secondary hardening peak (max hot hardness) and transform retained austenite. Temper above intended service temperature. | --- ## **Product Applications** CS5 is specialized for high-temperature tooling where thermal fatigue and hot strength are limiting factors. ### **Primary Hot Work Applications:** 1. **Aluminum Die Casting Dies:** Core pins, cavities, ejector pins, and goosenecks subjected to severe thermal cycling. 2. **Copper and Brass Extrusion Dies:** Mandrels, liners, and die holders for non-ferrous extrusion. 3. **Hot Forging Dies & Inserts:** For forging brass, copper, aluminum, and steel at moderate temperatures. 4. **Hot Stamping and Piercing Tools.** 5. **Pressure Die Casting Tools** for zinc and magnesium alloys. 6. **Glass Mold Tooling** for forming and handling. 7. **Heavy-Duty Hot Shear Blades.** ### **Industry Usage:** - **Non-Ferrous Die Casting** - **Metal Extrusion** - **Hot Forging** - **Glass Manufacturing** --- ## **International Standards & Cross-Reference** UNS T91905 (CS5) has specific equivalents in several international systems, though it is less common than H13. | Standard | Designation | Equivalent / Similar Grade | | :--- | :--- | :--- | | **UNS (USA)** | **T91905** | - | | **AISI (USA)** | **H12 Mod / H10 Mod** | (Closest AISI analogues) | | **ASTM (USA)** | A681 (possibly) | - | | **Europe (EN / DIN)** | **~1.2365** | 55NiCrMoV7 (Note: Ni-bearing, different composition) | | **Germany (DIN)** | **~1.2344** | X6CrMoV5-1 (Closer in Cr-Mo-V balance) | | **International** | - | Often considered a proprietary or modified H12/H13 grade. | **Note:** CS5 is not a universal standard grade like H13. Its composition suggests it is a modified **H12-type steel** (balanced Cr-Mo-V) or a proprietary grade. The UNS T91905 designation is its primary identifier. Always consult the mill certificate for exact composition. --- ## **Advantages & Considerations** ### **Advantages:** 1. **Excellent Thermal Fatigue Resistance:** Superior resistance to heat checking compared to many standard hot work steels. 2. **Good Combination of Hot Hardness & Toughness:** Maintains strength at temperature without becoming overly brittle. 3. **Good Oxidation Resistance:** Chromium content provides a protective scale at working temperatures. 4. **Good Hardenability & Through-Hardening:** Suitable for large, complex dies. ### **Considerations:** 1. **Specialized Grade:** Less common and potentially less readily available than H11, H12, or H13. 2. **Complex Heat Treatment Required:** Requires high austenitizing temperatures and precise multiple tempering. 3. **Not for Highest-Temperature Service:** For very high-temp applications (e.g., steel forging), tungsten-based hot work steels (H21-H26) may be more suitable. 4. **Cost:** Typically more expensive than standard H13 due to specialized alloying and lower production volume. --- ## **Comparison with Common Hot Work Grades** | Property | **CS5 (T91905)** | **H13** | **H11** | | :--- | :--- | :--- | :--- | | **Typical C Content** | 0.35-0.45% | 0.32-0.45% | 0.33-0.43% | | **Typical Cr Content** | 4.75-5.50% | 4.75-5.50% | 4.75-5.50% | | **Typical V Content** | **0.80-1.20%** | 0.80-1.20% | 0.30-0.60% | | **Key Difference** | Balanced for thermal fatigue | Most common, balanced all-around | Lower V, often tougher | | **Best For** | **Severe Thermal Cycling** | General-purpose hot work | High-toughness applications | --- ## **Conclusion** **CS5 Hot Work Tool Steel (UNS T91905)** is a **high-performance, engineered-grade material** designed for the most demanding hot work tooling applications where **thermal fatigue failure is the primary concern**. Its optimized chemistry, particularly its balanced chromium, molybdenum, and vanadium content, provides an exceptional blend of **hot hardness, thermal conductivity, and crack resistance**. While not as ubiquitous as H13, CS5 offers a targeted solution for die casting and extrusion tools that repeatedly fail due to heat checking. For tool engineers seeking to maximize the service life of critical hot work components operating under severe thermal cycling conditions, CS5 represents a sophisticated material choice that prioritizes long-term durability and performance stability at elevated temperatures. -:- For detailed product information, please contact sales. -: CS5 Hot Work Tool Steel (UNS T91905) Specification Dimensions Size： Diameter 20-1000 mm Length <6671 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. -: CS5 Hot Work Tool Steel (UNS T91905) Properties -:- For detailed product information, please contact sales. -:

Applications of CS5 Hot Work Tool Steel Tube (UNS T91905) -:- For detailed product information, please contact sales. -: Chemical Identifiers CS5 Hot Work Tool Steel Tube (UNS T91905) -:- For detailed product information, please contact sales. -:

Packing of CS5 Hot Work Tool Steel Tube (UNS T91905) -:- 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 Tube 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 3142 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