Hastelloy alloy 625,1

### **Introduction to Hastelloy® Alloy 625 and Related Specifications** **Hastelloy® Alloy 625** (often referred to as INCONEL® Alloy 625) is a nickel-chromium-molybdenum superalloy renowned for its exceptional combination of properties. Its outstanding strength and toughness are derived from the solid-solution strengthening effect of molybdenum and niobium in its nickel-chromium matrix. It exhibits excellent fatigue strength, superior resistance to a wide range of corrosive environments, including pitting, crevice corrosion, and oxidation, and high strength over a broad temperature range from cryogenic to 1800°F (1000°C). This alloy is covered by numerous international standards for its base metal forms (sheet, plate, bar, wire) and for the welding consumables used to join it. --- ### **1. Base Metal: Hastelloy® Alloy 625** The wrought forms of Alloy 625, such as sheet, plate, bar, and wire, are governed by specifications from organizations like SAE International (AMS) and ASTM. ***Correction and Clarification on Standards:*** * **AMS 5755, 5786, 5787:** These specific AMS standards are primarily for **Cobalt-Based Alloy 188** (as detailed in the previous response). For Alloy 625, the common AMS specifications are: * **AMS 5599:** Sheet, Strip, and Plate * **AMS 5666:** Bar, Forgings, and Rings * **AMS 5837:** Welding Wire #### **Chemical Composition (Weight %, typical per AMS 5599 / UNS N06625):** | Element | Minimum | Maximum | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance | --- | | **Chromium (Cr)** | 20.0 | 23.0 | | **Molybdenum (Mo)** | 8.0 | 10.0 | | **Niobium (Nb) + Tantalum (Ta)** | 3.15 | 4.15 | | **Iron (Fe)** | --- | 5.0 | | **Aluminum (Al)** | --- | 0.40 | | **Titanium (Ti)** | --- | 0.40 | | **Carbon (C)** | --- | 0.10 | | **Manganese (Mn)** | --- | 0.50 | | **Silicon (Si)** | --- | 0.50 | | **Phosphorus (P)** | --- | 0.015 | | **Sulfur (S)** | --- | 0.015 | *Balance is Nickel, along with incidental impurities.* #### **Physical Properties (Typical):** * **Density:** 8.44 g/cm³ (0.305 lb/in³) * **Melting Range:** 1290 - 1350 °C (2350 - 2460 °F) * **Electrical Resistivity:** 129 μΩ·cm at 21°C * **Thermal Expansion Coefficient:** 12.8 μm/m·°C (20-100°C) * **Thermal Conductivity:** 9.8 W/m·K at 100°C * **Modulus of Elasticity (Young's Modulus):** 207 GPa (30 x 10⁶ psi) at 21°C #### **Mechanical Properties (Typical at Room Temperature per AMS 5599 - Annealed Condition):** * **Tensile Strength:** ≥ 827 MPa (120 ksi) * **Yield Strength (0.2% Offset):** ≥ 414 MPa (60 ksi) * **Elongation:** ≥ 30% --- ### **2. Welding Consumables: ERNiCrMo-3 and ENiCrMo-3** To weld Alloy 625 and for cladding steel with a corrosion-resistant layer, matching-composition welding electrodes and wires are used. These are standardized by AWS and ASME. #### **Key Standards for Welding Consumables:** * **AWS A5.14 / ASME SFA-5.14:** Specification for Nickel and Nickel-Alloy Bare Welding Electrodes and Rods. * **Product:** **ERNiCrMo-3** (Bare welding wire for GTAW/TIG, GMAW/MIG, SAW processes). * **AWS A5.11 / ASME SFA-5.11:** Specification for Nickel and Nickel-Alloy Welding Electrodes for Shielded Metal Arc Welding. * **Product:** **ENiCrMo-3** (Covered electrodes for SMAW/Stick welding). #### **Chemical Composition of Welding Products (Weight %, AWS Requirements for ERNiCrMo-3):** | Element | ERNiCrMo-3 (AWS A5.14) | | :--- | :--- | | **Nickel (Ni)** | Balance | | **Chromium (Cr)** | 20.0 - 23.0 | | **Molybdenum (Mo)** | 8.0 - 10.0 | | **Niobium (Nb) + Tantalum (Ta)** | 3.15 - 4.15 | | **Iron (Fe)** | 5.0 max | | **Aluminum (Al)** | 0.40 max | | **Titanium (Ti)** | 0.40 max | | **Carbon (C)** | 0.10 max | | **Manganese (Mn)** | 0.50 max | | **Silicon (Si)** | 0.50 max | | **Cobalt (Co)** | 1.0 max | | **Phosphorus (P)** | 0.03 max | | **Sulfur (S)** | 0.015 max | *The composition for ENiCrMo-3 electrode weld metal is very similar, ensuring a matching deposit.* --- ### **Product Applications** Hastelloy Alloy 625's unique properties make it a critical material across multiple high-performance industries: * **Aerospace & Gas Turbines:** * Engine ducting, rings, and casings * Exhaust systems * Combustion liners * Afterburner components * **Marine & Offshore:** * Propeller and rudder shafting * Submarine components * Seawater heat exchangers and piping systems * **Chemical Processing:** * Reactors, heat exchangers, and piping in aggressive environments * Components exposed to chlorides, acids, and other corrosives * **Pollution Control:** * Flue gas desulfurization systems (scrubbers, dampers, fans) * **Nuclear Industry:** * Core components and control rod ducting * **Oil & Gas:** * Downhole and subsea equipment (e.g., umbilicals, control lines) --- ### **Summary of International Standards** | Product Form | Standard | Governing Body | Designation | | :--- | :--- | :--- | :--- | | **Sheet, Strip, Plate** | AMS 5599 | SAE International | Alloy 625 | | **Bar, Forgings, Ring** | AMS 5666 | SAE International | Alloy 625 | | **Welding Wire** | AMS 5837 | SAE International | Alloy 625 | | **Bare Welding Wire** | AWS A5.14 / ASME SFA-5.14 | American Welding Society / ASME | **ERNiCrMo-3** | | **Covered Electrodes** | AWS A5.11 / ASME SFA-5.11 | American Welding Society / ASME | **ENiCrMo-3** | | **Plate, Sheet, Strip** | ASTM B443 | ASTM International | UNS N06625 | | **Pipe & Tube** | ASTM B444 / B705 | ASTM International | UNS N06625 | **Note:** "Hastelloy" is a registered trademark of Haynes International, Inc., and "INCONEL" is a registered trademark of Special Metals Corporation. The specifications mentioned are industry standards used to define the technical requirements for procurement and quality assurance.

Packing of Standard Packing: 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 3255 gallon liquid totes Special package is available on request.