Inconel 625 Pipe
Steel Pipe & Tubes has been a leading supplier of Inconel alloy piping solutions.
High-Performance Alloy 625 Seamless Tube Manufacturer in India | Trusted UNS N06625 Tubing Sizes & Supplier
Stellar Alloys manufactures and stocks Inconel 625 Pipe and Inconel 625 Tube for high‑consequence applications in chemical processing, offshore and marine, power and aerospace. Our Inconel 625 Seamless Pipe and Inconel 625 Welded Pipe are produced through controlled melting with heat‑to‑heat chemistry control. They are finished to tight OD and wall tolerances and supplied with full heat‑treatment traceability and non‑destructive examination. We maintain mill‑certified UNS N06625 inventory in round, square and rectangular sections, offer cut‑to‑length, U‑bend and spool fabrication, and support fast project turnarounds from development lots to production quantities.
Documentation & Compliance: EN 10204 3.1 MTCs, PMI at dispatch, hydrostatic test certificates and NDT logs on request. Product forms comply with ASTM/ASME specifications (ASTM B444/B704/B705 and ASME SB equivalents). Round pipe dimensions per ASME B36.10/B36.19. General tolerances per ASTM B829 for nickel alloy tubing.
What Are Inconel 625 Pipes / Tubes?
Inconel 625 (Alloy 625, UNS N06625, W. Nr. 2.4856) is a nickel‑chromium‑molybdenum alloy strengthened by solid‑solution additions of niobium and molybdenum. Unlike precipitation‑hardening superalloys, Inconel 625 achieves high strength in the annealed or solution‑annealed condition, with excellent corrosion resistance in chloride‑bearing and reducing media. It also provides good oxidation resistance at elevated temperatures.
Corrosion and high‑temperature behavior
- Outstanding resistance to pitting and crevice attack in chloride media and seawater.
- Very good stress‑corrosion‑cracking resistance in chloride environments.
- Strong resistance to many mineral acids and sour service media when appropriately processed.
- Oxidation resistance typically up to about 980 °C with stable mechanical response at elevated temperatures.
Typical end uses Seawater and desalination equipment, offshore risers and downhole components, chemical process piping, heat‑exchanger and condenser tubing, furnace tubes, aircraft ducting and bellows, and high‑temperature instrumentation.
Types of Inconel Alloy 625 Pipes
Select the right Inconel 625 Pipe or Inconel 625 Tube for your duty—seamless to ASTM B444 for high‑integrity pressure service or welded to ASTM B705/B704 for economical large‑OD runs. Use this map to link UNS N06625 product forms to standards and typical applications so you can match form to temperature, pressure and corrosion duty.
Inconel 625 Pipe
UNS N06625 Welded Pipe
Alloy 625 Seamless Pipe
Inconel 625 Pipe Specifications
These are the governing specifications and delivery options for Alloy 625 pipe and tube. Stellar Alloys supplies Inconel 625 Seamless Pipe/Welded Pipe compliant with ASTM B444/B705/B704 (ASME SB) and general requirements per ASTM B829, with end finishes PE/BE/TE and finishes from mill to BA.
| Parameter | Details |
| Material Grade | Inconel 625, Alloy 625, UNS N06625, DIN/W.Nr. 2.4856 |
| Standards | ASTM B444 (seamless), ASTM B705 (welded pipe), ASTM B704 (welded tube), ASTM B751 (mechanical tests); ASME SB equivalents |
| Forms | Round, square and rectangular pipe/tube; ends: PE, BE, TE |
| Schedules | SCH 5S, 10S, 40S, 80S; thicker walls to drawing |
| Delivery Conditions | Annealed / Bright Annealed / Solution Annealed & Pickled |
| Finish | Mill finish, BA, pickled, polished 180–600 grit; honed ID/OD on request |
| NDT | Hydrostatic, eddy current, ultrasonic; radiography for welded as specified |
| Tolerances | As per ASTM B829 or agreed drawing |
| Certifications | EN 10204 3.1; third‑party inspection available |
Available Size Range of Inconel 625 Pipes
Our stocking and MTO window for Inconel 625 Pipes & Tubes spans small‑bore to large‑OD with schedules SCH 5S–160 and gauge‑based tube. Use this table to match OD, WT and length in seamless and welded forms.
| Form & Standard | OD range (mm) | NPS range (in) | Wall thickness range (mm) | Schedule / Gauge | Typical supplied lengths |
| Seamless Pipe — ASTM B444 / ASME SB444 | 4 – 219 | 1/8 – 8 | 0.5 – 20 | SCH 5S, 10S, 40S, 80S, 160 | SRL / DRL / cut‑to‑length |
| Welded Pipe — ASTM B705 / ASME SB705 | 5 – 1219.2 | 1 – 24+ | ≈0.5 – 25 | SCH 5S, 10S, 40S, 80S, 120, 160 | SRL / DRL / custom lengths |
| Seamless Tube — ASTM B444 | 6.35 – 114.3 | — | 0.8 – 12.7 (≈ 25–10 SWG) | Thickness by mm/SWG (no schedules) | Straight up to ~26,000 mm; coils/U‑bends |
| Welded Tube — ASTM B704 / ASME SB704 | 6.35 – 152 | — | ≈0.71 – 3.25 (22–10 gauge) | Gauge‑based; eddy‑current/hydro tested | Straight up to ~6,000 mm; U‑bends available |
Note: Ranges are indicative and vary with mill batch, schedule/gauge and project specifications.
ASTM B444 UNS N06625 Tube Dimensions & Thickness Chart
Plan heat‑exchanger or instrumentation circuits with this ASTM B444 chart for Inconel 625 Seamless Tube. OD/WT pairs include approximate IDs to estimate velocities and pressure drops.
Indicative dimensions for stock planning. Detailed drawings provided at order stage.
| OD (mm) | OD (inch) | Typical WT (mm) | Approx. ID (mm) |
| 12.7 | 1/2 | 1.24 | 10.22 |
| 15.88 | 5/8 | 1.24 | 13.40 |
| 19.05 | 3/4 | 1.65 | 15.75 |
| 25.40 | 1 | 2.11 | 21.18 |
| 31.75 | 1‑1/4 | 2.11 | 27.53 |
| 38.10 | 1‑1/2 | 2.77 | 32.56 |
| 50.80 | 2 | 3.05 | 44.70 |
| 60.33 | 2‑3/8 | 3.38 | 53.57 |
| 73.03 | 2‑7/8 | 3.56 | 65.91 |
| 88.90 | 3‑1/2 | 4.19 | 80.52 |
Pressure Ratings of ASTM B444 Inconel 625 Square Pipes (Indicative, 38 °C / 100 °F)
Calculated with a conservative thin-wall analogy using hydraulic width (P ≈ 2 S t / bᵢ where S = 184 MPa allowable for ASTM B444 Gr.2 at 20–100 °F; bᵢ = side − 2t). Seam efficiency E = 1.00 (seamless) and E = 0.85 (welded). Use for preliminary selection only; finalize per ASME B31.3/B31.1 with temperature derating, joint quality and geometry factors. Basis for S: Swagelok MS-01-107.
| Side × WT (mm) | Working Pressure — Seamless (bar) | Working Pressure — Welded (bar) |
| 20 × 1.5 | 325 | 276 |
| 25 × 2.0 | 350 | 298 |
| 30 × 2.0 | 283 | 241 |
| 40 × 2.5 | 263 | 223 |
| 50 × 3.0 | 251 | 213 |
| 50 × 4.0 | 350 | 298 |
| 50 × 5.0 | 460 | 391 |
| 60 × 3.0 | 204 | 174 |
| 60 × 4.0 | 283 | 241 |
| 75 × 3.0 | 160 | 136 |
| 75 × 4.0 | 220 | 187 |
| 75 × 5.0 | 283 | 241 |
| 100 × 4.0 | 160 | 136 |
| 100 × 5.0 | 204 | 174 |
| 100 × 6.0 | 251 | 213 |
| 120 × 5.0 | 167 | 142 |
| 120 × 6.0 | 204 | 174 |
Methodological note only; not a code stamp. Use project-specific calculations before release to service.
Inconel UNS N06625 Hollow Pipe Pressure Ratings (Seamless Tube, 38 °C / 100 °F)
Allowable working pressures per Swagelok MS-01-107 Table 23 — Metric Alloy 625 Tubing (ASTM B444 Gr. 2; S = 184 MPa at 20–100 °F). Values below are the published working pressure (bar) for common metric sizes.
| OD (mm) | WT (mm) | Working Pressure (bar) |
| 3 | 0.8 | 670 |
| 4 | 1.0 | 500 |
| 4 | 1.2 | 660 |
| 6 | 1.0 | 470 |
| 6 | 1.2 | 610 |
| 6 | 1.5 | 750 |
| 10 | 1.0 | 350 |
| 10 | 1.2 | 430 |
| 10 | 1.5 | 550 |
| 12 | 1.0 | 290 |
| 12 | 1.2 | 350 |
| 12 | 1.5 | 440 |
| 12 | 1.8 | 550 |
| 18 | 1.0 | 250 |
| 18 | 1.2 | 300 |
| 18 | 1.5 | 340 |
| 18 | 1.8 | 380 |
| 18 | 2.0 | 400 |
| 25 | 1.2 | 240 |
| 25 | 1.5 | 270 |
| 25 | 1.8 | 300 |
Weight Chart of DIN 2.4856 Rectangular Pipes
Calculated with density 8.44 g/cm³ (Alloy 625). For guidance only; actual weight varies with tolerances and corner radii.
| Size (B × H × t), mm | Approx. Weight (kg/m) |
| 40 × 20 × 2.0 | 1.89 |
| 50 × 25 × 3.0 | 3.49 |
| 60 × 40 × 3.2 | 5.06 |
| 75 × 50 × 3.0 | 6.03 |
| 75 × 50 × 5.0 | 9.71 |
| 80 × 40 × 4.0 | 7.56 |
| 90 × 50 × 4.0 | 8.91 |
| 100 × 50 × 4.0 | 9.59 |
| 100 × 50 × 6.0 | 13.98 |
| 100 × 75 × 4.0 | 11.28 |
| 100 × 75 × 5.0 | 13.93 |
| 120 × 60 × 4.0 | 11.61 |
| 150 × 75 × 5.0 | 18.15 |
| 150 × 100 × 6.0 | 24.10 |
| 200 × 100 × 6.0 | 29.17 |
| 200 × 100 × 8.0 | 38.35 |
| 250 × 150 × 6.0 | 39.30 |
| 300 × 150 × 8.0 | 58.61 |
Weight formula:
W≈ρ×[B⋅H−(B−2t)(H−2t)]×10−6W \approx \rho \times \big[B\cdot H – (B-2t)(H-2t)\big] \times 10^{-6}W≈ρ×[B⋅H−(B−2t)(H−2t)]×10−6 kg/m, where ρ=8440\rho = 8440ρ=8440 kg/m³; B, H, t in mm.
ASME SB444 Alloy 625 Hexagonal Pipe Characteristics
Stellar Alloys supplies ASME SB444 Alloy 625 hexagonal pipe/hex nipples engineered for compact, wrench-friendly connections in demanding services. Typically machined from SB444 (seamless) or SB705 (welded) mother pipe—or from Alloy 625 hex bar—these parts retain the corrosion and high-temperature strength of UNS N06625. We support NPT/BSPT threads, pressure classes (3K/6K/9K), and finishing options for clean, leak-tight make-up. Use the table below to finalize AF size, thread form, and test documentation.
| Parameter | Details |
| Product form | Hexagonal pipe/hex nipple, typically machined from ASME SB444 (seamless) or ASME SB705 (welded) mother pipe/tube; hex may also be made from Alloy 625 hex bar then threaded per order. |
| Grade & IDs | Inconel® 625 / Alloy 625 — UNS N06625, W.Nr. 2.4856 (Ni-Cr-Mo-Nb solid-solution alloy). |
| Typical size range | 1/8″ NB to 4″ NB for hex nipples/hex pipe pieces; larger AF sizes on request (machined from bar or pipe). Pressure classes commonly 3000, 6000, 9000 for threaded pieces. |
| Threads / ends | NPT (ASME B1.20.1), BSP/BSPT (ISO 7/1) male/female; also PE/BE blanks for site machining. BSP×NPT adaptors are common in 625. |
| Finishes | Bright-annealed, pickled, polished (180–600 grit); electropolish available from some fittings vendors. |
| Inspection & testing | PMI at dispatch, thread-gauge checks, hydro/pneumatic as ordered; documentation to EN 10204 3.1 when supplied as piping components. (Practices align with leading fittings suppliers.) |
| Mechanical/temperature notes | 625 offers high tensile, creep and fatigue strength, excellent oxidation & chloride SCC resistance; suitable from cryogenic to ~980 °C (1800 °F) in oxidizing service (design per code). |
| Typical uses | Instrumentation tie-ins, chemical dosing lines, high-temperature headers and OEM skids where a compact hex profile eases wrenching and leak-tight threaded make-up. BSP×NPT transitions are common in global projects. |
Notes: “Hexagonal pipe” is generally produced as short hex sections or hex nipples—either turned from SB444/SB705 round tube/pipe or from 625 hex bar—rather than as mill-made continuous hex-section pipe. Confirm AF, thread class, and pressure class on the approved drawing before manufacture.
HSN Code of Inconel 625 Seamless Pipes
Use this quick guide to classify Inconel 625 Pipe and Inconel 625 Tube (nickel-alloy products) correctly for India shipments. Entries cover tubes/pipes and allied nickel fittings commonly supplied with Alloy 625 spools and skids. Rates and subheadings can change—treat this as a starting point and confirm with your customs broker. Proper HSN mapping helps you avoid clearance delays and re-work.
| Product form (nickel‑alloy) | HSN code (India) | Description (official) | Typical applicability | GST* |
| Tubes & Pipes (seamless or welded) | 7507 12 00 | “Nickel tubes and pipes — of nickel alloys” | Inconel 625 seamless pipe, welded pipe, seamless/welded tube, square/rectangular | 18% |
| Tubes & Pipes (of pure nickel, not alloyed) | 7507 11 00 | “Nickel tubes and pipes — of nickel, not alloyed” | Pure‑nickel grades only (not Inconel) | 18% |
| Tube or Pipe Fittings (nickel) | 7507 20 00 | “Nickel tube or pipe fittings (couplings, elbows, sleeves)” | Inconel 625 elbows, tees, reducers, nipples, bush hex, etc. | 18% |
Verify final classification/rate with your customs broker and latest notifications.
Manufacturing Process of Alloy 625 Pipes
Every Alloy 625 Pipe/Tube from Stellar Alloys follows a controlled route—from melting and billet conversion to seamless/welded production, solution/bright anneal, and calibrated sizing. We maintain full heat traceability and record NDT + hydro/pneumatic tests to align with ASTM B444/B705/B704 and ASTM B829 requirements. The steps below outline how we deliver clean, code-ready Inconel 625 with repeatable properties.
- Primary Melting and Refining: Vacuum induction melting with secondary refinement for tightly controlled residuals and gases.
- Billet Conversion: Hot forging/rolling into billet or hollow. UT inspection and surface conditioning as specified.
- Seamless Route: Hot pierce and mandrel mill, then cold pilgering or drawing to final size for refined surface and dimensional accuracy.
- Welded Route: Precision slit strip roll‑formed and fusion welded; solution annealed to restore corrosion performance.
- Heat Treatment: Solution or bright anneal in controlled atmosphere to produce a clean surface and stable austenitic matrix.
- Sizing and End Finishing: Tight OD/WT/ovality per ASTM B829. Ends PE, BE or threaded to order.
- Cleaning and Passivation: Pickling or mechanical descaling; optional passivation for cleanliness.
- Inspection and Certification: Hydro/pneumatic leak tests, eddy current or ultrasonic NDT, mechanical testing and full traceability on MTCs.
Physical Properties of DIN 2.4856 Square Pipes (Annealed Condition)
Designers rely on baseline physical data for UNS N06625 / DIN 2.4856 to size supports, expansion loops, and heat-transfer surfaces. The table lists density, modulus, resistivity, thermal conductivity, and CTE for Inconel 625 in the annealed condition. Use these values when modeling Alloy 625 square/rectangular hollows under thermal cycling and mixed media. Always pair with project-specific allowables for final design.
| Property | Value |
| Density | ~8.44 g/cm³ |
| Melting Range | ~1290–1350 °C |
| Modulus of Elasticity | ~205 GPa |
| Poisson’s Ratio | ~0.30 |
| Electrical Resistivity (20–23 °C) | ~1.26–1.30 μΩ·m |
| Thermal Conductivity (100 °C) | ~9.5–10.5 W/m·K |
| Coefficient of Thermal Expansion (20–100 °C) | ~12.8–13.2 μm/m·°C |
Temperature Range of UNS N06625 Welded Pipes
This operating window summarizes practical service bands for Inconel 625 Welded Pipe, from cryogenic duties to elevated temperatures. It highlights where corrosion resistance is routine, where creep begins to govern, and the typical upper limit for continuous oxidizing service. Use it for early selection, then finalize to ASME B31.3/B31.1 with temperature derates and weld efficiency.
| Service band | °C | °F | Welded‑pipe suitability (summary) | Typical notes / uses |
| Cryogenic to ambient | down to ~‑196 | down to ~‑320 | Fully usable; welds retain ductility (annealed). | Low‑temp instrumentation and process lines. |
| Ambient to 650 | 20–650 | 68–1200 | Routine duty; corrosion resistance excellent. | Chemical/utility piping; confirm media compatibility. |
| Elevated service | 650–980 | 1200–1800 | Good oxidation/corrosion; creep governs—use Grade 2 and design to code. | Furnace/heater/hot process headers. |
| Upper practical (oxidizing) | up to ~980 | up to ~1800 | Typical top end for continuous service—check ASME IID allowables. | Oxidation‑resistant duty near limit. |
Stress Rupture Properties of Inconel 625 Bright Annealed Pipes
Long-term strength at temperature is critical for Alloy 625 in heaters, headers, and hot process lines. The table provides indicative rupture stresses vs. time at key temperatures for bright/solution-annealed material. Treat these as screening values only—final design must reference code allowables, heat condition, and application-specific test data.
| Temperature | 100 h to rupture | 1000 h to rupture |
| 600 °C (1112 °F) | 440 MPa | 302 MPa |
| 650 °C (1202 °F) | 275 MPa | 190 MPa |
| 700 °C (1292 °F) | 170 MPa | 110 MPa |
| 750 °C (1382 °F) | 98 MPa | 62 MPa |
| 800 °C (1472 °F) | 57 MPa | 34 MPa |
| 850 °C (1562 °F) | 30 MPa | 14 MPa |
| 900 °C (1652 °F) | 14 MPa | 6 MPa |
Values are indicative from standard datasheet practice; project design must use code allowables.
Testing & Quality Standards for Nickel Alloy 625 ERW Pipes
Stellar Alloys runs a documented QA/QC plan for Nickel Alloy 625 ERW Pipes to control identity, weld integrity, and dimensional accuracy. Each order can include PMI, hydro/pneumatic leak tests, and calibrated EC/UT/RT as specified, plus mechanicals to ASTM B751 and general requirements to ASTM B829. The checklist below streamlines audits for Inconel 625 projects under ASME B31.1/B31.3.
Material Identity: 100% PMI on heats with random piece checks.
Leak Integrity: Hydrostatic or pneumatic testing to agreed pressures and hold times with certificates.
Non‑Destructive Examination: Eddy current for thin walls, ultrasonic for heavier sections and radiography for weld seams when ordered.
Mechanical Qualification: Tensile, yield, elongation, flattening, flange, reverse‑bend and hardness tests per ASTM B751 and drawing.
Dimensional Compliance: OD, wall, ovality and straightness checked against ASTM B829 and customer prints.
Surface Quality: Visual inspection for laminations, pits, dents and weld undercut; roughness control available for critical services.
Documentation: EN 10204 3.1 certification, packing lists, heat maps and barcode traceability
Most Popular Types of Inconel 625 Alloy Pipes
This shortlist highlights the most ordered Inconel 625 Seamless Pipe and Alloy 625 Tube configurations for steam, chemical, and seawater duty. Options span SCH 5S–160, BA/AP finishes, and U-bend capability for compact exchanger layouts. Use it as a quick selector, then request MTCs and NDT plans for approval.
Inconel 625 Seamless Pipe, SCH 40S, 1/2″ to 4″ — Standard-pressure process lines with high strength and corrosion resistance; tight OD/WT tolerances for ASME B31.3 duty.
Inconel 625 Welded Pipe, large OD up to 24″ — Cost-efficient headers and exhausts in big diameters; solution-annealed with optional radiography for critical service.
Inconel 625 Seamless Tube for heat exchangers — Clean ID and controlled ovality for efficient heat transfer; bright-annealed with U-bend capability.
Inconel 625 Welded Tube for condensers and coolers — Precision roll-formed, fusion-welded, sized and annealed; hydro/eddy-current tested for leak-tight service.
DIN 2.4856 Square Pipes for structural service — High-temperature, corrosion-resistant hollows with stable geometry; custom corner radii and wall options.
DIN 2.4856 Rectangular Pipes for frames and supports — Directional stiffness for skids and frameworks; cut-to-length with engineered thickness selection.
Inconel 625 Bright Annealed Pipes for clean service — Low-roughness, scale-free surfaces for high-purity media and instrumentation loops; reduced fouling.
Inconel 625 ERW Pipes for utility service — Consistent seam quality for air, water, jacket and general utilities; fast availability and economical runs.
Specification Sheet of Inconel 625 Bush Hex Pipes
For threaded tie-ins and compact assemblies, Inconel 625 bush hex parts deliver strength and corrosion resistance in a wrench-friendly profile. The spec sheet below condenses size ranges, schedules, thread standards (NPT/BSPT), finishes, and test options. Include AF size, pressure class, and end form on your RFQ for a rapid, accurate quote.
| Field | Specification |
| Product | Inconel 625 Bush Hex Pipe / Hex Nipple |
| Grade | UNS N06625, DIN 2.4856 |
| Size Range | 1/4″ to 4″ NPS; custom across‑flats on request |
| Thickness | Schedule 10S to Schedule 80S |
| Ends | Male/Female threaded (NPT/BSPT), bevel or plain |
| Finish | Bright annealed, pickled, polished |
| Standards | ASTM B444/B705 for mother pipe; threads to ASME B1.20.1 or ISO 7/1 |
| Testing | Hydro test, thread gauge check, PMI |
| Applications | Instrument connections, chemical dosing, high‑temperature tie‑ins |
Latest Price List of Alloy 625 Seamless Tubes
Budgeting Alloy 625 Seamless Tube depends on OD/WT, finish (BA/AP), quantity, and nickel surcharges. The matrix below provides indicative guidance for common sizes and MOQs. For live pricing, share your cut lengths, testing, and documentation needs—we’ll align a quote and JIT options to your build schedule
| OD × WT (mm) | Condition | Typical MOQ | Indicative Pricing |
| 12.7 × 1.24 | Bright Annealed | 100 m | Price on Request |
| 19.05 × 1.65 | Annealed | 100 m | Price on Request |
| 25.4 × 2.11 | Annealed & Pickled | 200 m | Price on Request |
| 38.1 × 2.77 | Annealed | 100 m | Price on Request |
| 50.8 × 3.05 | Annealed | 50 m | Price on Request |
Why Choose Stellar Alloys for Inconel 625 Pipes & Tubes?
Full Range: Inconel 625 Seamless Pipe, Inconel 625 Welded Pipe, Seamless/Welded Tube, square and rectangular sections.
Process Discipline: Qualified weld procedures, documented heat cycles and calibrated test equipment for repeatable properties.
Applications Support: Guidance for corrosion environment, temperature regime and code selection such as ASME B31.1 and B31.3.
Value‑Added Fabrication: Saw cutting, beveling, threading, U‑bending and spooling to compress schedules.
Global Logistics: Export‑ready packaging and markings aligned with import requirements.
Frequently Asked Questions About Inconel 625 Pipe
No. Inconel 625 is a nickel‑chromium‑molybdenum superalloy with niobium additions. It is not stainless steel. It offers higher resistance to pitting, crevice attack and chloride stress‑corrosion cracking compared with common austenitic stainless steels.
Alloy 600 is a Ni‑Cr‑Fe solid‑solution alloy with good high‑temperature oxidation resistance. Alloy 625 adds molybdenum and niobium for much higher strength and superior pitting and crevice corrosion resistance, especially in seawater and many acids. 625 is often selected for offshore and sour‑service duties.
In the annealed condition, Inconel 625 is generally non‑magnetic or only slightly responsive. Cold work can increase magnetic response. For low‑magnetic applications, specify annealed tubing and request permeability checks on the MTC.
Typical uses include seawater systems, desalination, offshore risers, chemical process piping, furnace tubes, aerospace ducting and bellows, and heat‑exchanger tubing where corrosion resistance and elevated‑temperature strength are required.
Use matching chemistry consumables such as ENiCrMo‑3 for SMAW and ERNiCrMo‑3 for GTAW/GMAW. Maintain interpass temperature control and post‑weld cleaning to preserve corrosion performance.
