AWS Class ERTi-7 MIG & TIG
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ERTi-7 Titanium TIG Filler Rod & MIG Wire Supplier in India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified supplier and stockist of ERTi-7 titanium welding wire (Ti-0.2Pd), classified under AWS A5.16 / ASME SFA-5.16, We supply this palladium-bearing filler metal from Mumbai, India, as TIG rods and MIG spools for GTAW, GMAW, and PAW processes.
Also known as UNS R52400 (Werkstoff Nr. 3.7236, EN ISO 24034 S Ti 2401 / TiPd0.2A). ERTi-7 is a specific grade of economically pure titanium alloyed with palladium in concentrations ranging from 0.12% to 0.25%. This titanium alloy alters its corrosion potential to the passive zone, providing substantial resistance to reducing acids, including dilute hydrochloric acid (HCl), dilute sulphuric acid (H₂SO₄), and elevated-temperature organic acids. The material has a tensile strength of 345 MPa (50,000 psi) in all weld metals, along with a yield strength of 275 MPa (40,000 psi) and elongation of 20%. Welding consumables that can be used include TIG rods of diameters ranging from 1.0 to 3.2 mm and MIG spools with diameters of 0.9 and 1.2 mm. The welding procedure involves direct current electrode negative polarity with 100% ultra-high purity argon shielding and a trailing shield until the weldment cools to below 427°C (800°F).
This material is optimised for chemical processing, heat exchangers prone to crevice corrosion, and seawater systems operating at elevated temperatures. It meets NACE MR0175 standards for sour service and is suitable for pharmaceutical reactors, with all shipments including MTC 3.1 certification according to EN 10204.
ERTi-7 Welding Wire Specifications
The table below includes information on the classification, process, shielding, dimensions, and more for ERTi-7
| AWS Classification | ERTi-7 as per AWS A5.16 / A5.16M |
|---|---|
| UNS | R52400 |
| Welding Processes | GTAW (TIG), GMAW (MIG), PAW |
| Polarity | DCEN (all processes) |
| Shielding Gas | 100% Argon (99.995% min UHP welding grade) |
| TIG Rod Diameters | 1.0, 1.6, 2.4, 3.2 mm |
| MIG Wire Diameters | 0.9, 1.2 mm |
| TIG Rod Length | 914 mm (36″) or 1000 mm |
| MIG Spool Sizes | 5 kg, 8 kg, 10 kg (D200/D300) vacuum-sealed |
What Does ERTi-7 Mean? - AWS A5.16 Classification Explained
Please review the table below for a complete look at the technical standards for ERTi-7 titanium wire, along with the official AWS A5.16 industry-wide classifications.
| Component | Meaning & Specification | Key Benefit |
|---|---|---|
| ER | Electrode / Rod: Bare solid wire. | Compatible with high-precision TIG and MIG welding. |
| Ti | Titanium base alloy. | Guarantees the lightweight, high-strength properties of titanium. |
| 7 | Grade 7 (Ti-0.15Pd): Palladium-added grade. | Provides the highest corrosion resistance in reducing acids. |
ERTi-7 has 0.2% palladium added to its Grade 7 titanium filler metal, giving it superior resistance to corrosive environments that are acidic in nature, even though its tensile properties are similar to Grade 2 titanium filler metal.
Weld Deposit Chemical Composition of ERTi-7 Filler Wire
The chemical composition of the ERTi-7 weld deposit per AWS A5.16 is given below. Palladium is the defining element separating ERTi-7 from ERTi-2.
| Specification | Carbon (C) | Oxygen (O) | Nitrogen (N) | Hydrogen (H) | Iron (Fe) | Palladium (Pd) | Titanium (Ti) |
|---|---|---|---|---|---|---|---|
| AWS A5.16 Req. (%) | 0.03 max | 0.08–0.16 | 0.015 max | 0.008 max | 0.12 max | 0.12–0.25 | Remainder |
When titanium corrodes in reducing acid, Pd concentrates on the dissolving surface and shifts the open-circuit potential into the passive region, re-establishing the TiO₂ oxide film. Oxygen above 0.16% embrittles the weld; hydrogen above 0.008% risks hydride cracking. Back purge and trailing shield are mandatory to prevent contamination.
All-Weld-Metal Mechanical Properties of ERTi-7
Consult the subsequent table for the mechanical property parameters of ERTi-7 all-weld metal, encompassing tensile strength and elongation.
| Specification | Tensile Strength | Yield Strength | Elongation |
|---|---|---|---|
| Typical Value | 345 MPa (50,000 psi) | 275 MPa (40,000 psi) | 20% |
These values match ERTi-2. Pd does not increase strength; its purpose is exclusively corrosion enhancement. For higher strength, ERTi-12 offers 485 MPa (70,000 psi) tensile strength through Mo + Ni alloying.
Base Metal Compatibility and P-Number Matrix for ERTi-7
Refer to the following table for ERTi-7 base metal compatibility and the corresponding P-Number matrix for welding procedure qualification.
| Base Metal | UNS | ASME P-No. | Joint Type |
|---|---|---|---|
| Titanium Grade 7 (Ti-0.2Pd) | R52400 | P-51 | Similar — primary application |
| Titanium Grade 2 (CP) | R50400 | P-51 | Similar — ERTi-7 as corrosion upgrade filler |
| Titanium Grade 16 (Ti-0.05Pd) | R52402 | P-51 | Similar — lower Pd variant |
| Titanium Grade 26 | R52404 | P-51 | Similar — Ru-bearing variant |
Titanium welding utilises F-51 filler under SFA 5.16; while a WPS qualified with ERTi-7 covers other F-51 fillers per QW-433, ERTi-5 must be used for Grade 5 base metals.
Recommended Welding Parameters for ERTi-7 TIG & MIG Wire
Refer to the following table for the optimal welding parameters and technical settings required for ERTi-7 TIG and MIG applications.
| Rod Diameter | Amperage (A) | Gas Cup Size | Base Thickness |
|---|---|---|---|
| 1.6 mm (1/16″) | 80–150 | 3/8″ | 1.6–3.2 mm |
| 2.4 mm (3/32″) | 150–250 | 3/8″ | 3.2–4.8 mm |
| 3.2 mm (1/8″) | 200–375 | 1/2″ | 6.3–12.7 mm |
Titanium welding requires argon flow rates of 8–12 L/min for the primary cup, 12–20 L/min for trailing shields, and 5–10 L/min for back purging; no preheat is allowed, interpass temperatures must stay below 175°C, and colour inspection must confirm a silver or bright finish.
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Industrial Welding Applications of ERTi-7 Filler Wire
Here are the industrial applications for ERTi-7
- Acidic Chemical Processing: Used in reactors and pipes for diluted hydrochloric or sulphuric acid. Palladium protects the metal from dissolving in difficult, acidic situations; hence, it is chosen.
- Crevice-Prone Heat Exchangers: Used for complex joints and flange faces to prevent crevice corrosion in low-oxygen environments where standard titanium would typically fail.
- Oil and Gas - Sour Service: Built for high-pressure offshore drilling, it prevents cracking and corrosion in H2S and CO2 environments at critical flange and seal connections.
- High-Temperature Seawater: Used in desalination and offshore cooling, it stops rapid saltwater corrosion in hot condenser crevices where seawater exceeds 80°C.
- Nuclear and Atomic Energy: Employed in containers and piping for radioactive waste management. It is selected for its ability to maintain a stable, protective film even when exposed to the aggressive acidic media often found in waste handling.
- Pharmaceutical Production: Used in specialised reactors that undergo repeated cleaning cycles. It ensures that the medicine produced is pure and can withstand the damage that often happens at weld points during strong cleaning processes.
Storage and Handling of ERTi-7 Welding Wire
Titanium filler wire is extremely sensitive to interstitial contamination. Keep in original sealed packaging until use; reseal immediately after. Store at 15–35°C, <60% RH, separated from ferrous materials and copper alloys. Clean rods with acetone before use and handle with lint-free gloves only. Use stainless steel brushes dedicated to titanium. ERTi-7 bare wire does not require re-baking.
Available Forms, Diameters and Packaging of ERTi-7 Wire
Review the data below for available forms, standard diameters, and packaging options to select the ideal ERTi-7 delivery format.
| Form | Diameters | Packaging |
|---|---|---|
| TIG Rod (GTAW) | 1.0, 1.6, 2.4, 3.2 mm | 5 kg sealed tubes, 914 or 1000 mm cut lengths |
| MIG Spool (GMAW) | 0.9, 1.2 mm | 5 kg, 8 kg, 10 kg vacuum-sealed spools (D200/D300) |
All wire ships with MTC 3.1 per EN 10204, documenting chemical analysis (O, N, H, C, Pd), mechanical properties, and heat/lot traceability.
How to Order ERTi-7 Welding Filler Metal from Nicorex Alloys
To place an order for ERTi-7 welding filler metal from Nicorex Alloys, kindly share the following 10 details:
- AWS Classification: ERTi-7 per AWS A5.16 / ASME SFA-5.16
- Diameter: 1.6 mm / 2.4 mm / 3.2 mm; cut lengths 914 mm / 1000 mm
- Quantity: Specify kg or number of tube packs
- Testing / Certification: MTC EN 10204 3.1/3.2; PMI Report; ASTM B863 compliance; TPI
- Base Metal: CP Ti Grade 7 (UNS R52401) / Grade 2 / Grade 16 - specify
- Material Grade: CP Ti Grade 7; UNS R52401; W.Nr. 3.7235; AWS A5.16: ERTi-7
- Third-Party Approvals: DNV / ABS / LR / TÜV - specify per application
- Applicable Code: ASME IX; AWS D1.9; ASTM B265 - specify
- Delivery: Domestic / International - specify port or address
- Remarks: 99.999% pure Ar shielding + back purge mandatory; confirm Grade 7 or Grade 2/16 base metal
Nicorex Alloys, as a distributor of titanium welding consumables, supplies ERTi-7 TIG rods and MIG wire from the same certified heat. The complete range (ERTi-1, ERTi-2, ERTi-5, ERTi-7, ERTi-9, ERTi-12) is available from stock.
Frequently Asked Questions
What is the Difference Between ERTi-7 and ERTi-12?
Different alloying improves corrosion resistance beyond CP Grade 2. ERTi-7 employs Pd (0.12–0.25%), and ERTi-12 uses Mo (0.2–0.4%) + Ni (0.6–0.9%). ERTi-12 delivers higher strength (485 MPa vs 345 MPa). ERTi-7 is preferred for reducing acids where palladium’s catalytic surface mechanism is most effective.
What Spool Sizes and TIG Rod Lengths are Available for ERTi-7?
TIG rods are available in diameters from 1.0 to 3.2 mm in 5 kg tubes, while MIG wire is supplied in 0.9 and 1.2 mm vacuum-sealed spools, all including MTC 3.1 certification
When should ERTi-7 Welding Wire not be used?
Do not use ERTi-2 in oxidising environments where it provides adequate resistance, as Pd adds cost without benefit. Do not use where higher strength is needed (ERTi-12 at 485 MPa or ERTi-5 at 895 MPa). Never substitute for ERTi-5 in aerospace joints. Titanium welding requires high-purity inert shielding to prevent ambient contamination and embrittlement, as CO₂, O₂, N₂, and active gases are absolutely prohibited.
Can ERTi-2 be Substituted for ERTi-7 in Reducing Acid Service?
No.ERTi-2 without Pd corrodes more in reducing acids. Palladium in ERTi-7 remains inactive in dilute HCl, H₂SO₄, and heated organic acids. Replace ERTi-2 in such service risks, rapid weld zone corrosion, and through-wall failure.