AWS Class E347-16 Welding Electrodes

E347-16 Stainless Steel Welding Electrode Mumbai

Name: AWS Class E347-16 Welding Electrodes
Brand: Nicorex Alloys

Nicorex Alloys is an ISO 9001 and 14001 certified importer, stockist, and supplier of E347-16 SS welding electrode. We provide these welding electrodes as classified under AWS A5.4 / ASME SFA 5.4. We maintain a ready inventory of E347-16 stainless steel coated electrodes across all standard diameters.

E347-16 is a rutile-coated (-16) austenitic stainless steel SMAW electrode designed for welding AISI 347, 321, 304, and 302 stainless steels. Its UNS designation is W34710. The weld deposit contains approximately 19.15% Chromium and 10.0% Nickel, with Nb + Ta = 10 × C minimum, 1.0% maximum. Typical all-weld-metal tensile strength reaches 86,500 psi (596 MPa), yield strength sits near 58,000 psi (400 MPa), and elongation holds at 34.5%. Niobium ties up carbon as stable NbC precipitates, keeping chromium intact at grain boundaries through the 425–850°C sensitisation range. When austenitic stainless steel weldments face sustained exposure above 400°C or must undergo post-weld heat treatment, E347-16 is the niobium-stabilised welding electrode that prevents the sensitisation-induced intergranular corrosion.

Available diameters include 2.4 mm (3/32″), 3.2 mm (1/8″), 4.0 mm (5/32″), and 4.8 mm (3/16″) × 350 mm. The stick electrode operates in all positions on AC or DCEP, covering P-8 Group 1 base metals such as AISI 347 (S34700), 321 (S32100), 304 (S30400), and 302 (S30200). Its EN ISO 3581-A equivalent is E 19 9 Nb R 1 2. Key industries span nuclear power, chemical processing, petrochemical refining, and food and beverage manufacturing. Every batch ships with an EN 10204 MTC 3.1 test certificate.

E347-16 Welding Electrode Specifications & Compliance Standards

These technical specifications and code classifications apply to E347-16 niobium-stabilised stainless steel electrodes for SMAW applications:

AWS Classification	E347-16
ASME SFA Standard	SFA 5.4
UNS Number	W34710
Base Metal ASME P-Number	P-8 Group 1 (300-series austenitic stainless steel)
Welding Process	SMAW (Shielded Metal Arc / Stick Welding)
Coating Type	Rutile (Titania, “-16” designation)
Current / Polarity	AC or DCEP
Welding Positions	All positions (F, V, OH, H)
Available Diameters	2.4 mm (3/32″), 3.2 mm (1/8″), 4.0 mm (5/32″), 4.8 mm (3/16″)
Electrode Length	350 mm (14″)
Deposition Efficiency	~65%
Stabilising Element	Niobium (Nb): 8×C min – 1.0% max
Delivery Condition	Hermetically sealed cans or vacuum-packed

Understanding the E347-16 Classification — AWS A5.4 Breakdown

The AWS A5.4 classification encodes the weld deposit composition, stabiliser type, and electrode usability. Each character carries a specific technical meaning for consumable selection:

Designator	Meaning
E	Electrode for electric arc welding
347	Weld deposit matching AISI 347 (18Cr-10Ni with Nb stabilisation)
-16	Rutile (titania) coating, AC/DCEP capable, all-position welding

The “347” portion indicates niobium (Nb, formerly called columbium/Cb) is present as a stabiliser. Nb reacts with carbon to form stable niobium carbides (NbC), preventing chromium carbide (Cr₂₃C₆) formation at grain boundaries through the 425–850°C sensitisation range. E308L-16 relies on low carbon (≤0.03%) to limit sensitisation. E347-16 uses Nb stabilisation instead, allowing higher carbon (up to 0.08%) while holding intergranular corrosion resistance above 400°C.

Weld Deposit Chemical Composition of E347-16 (%)

The chemical composition below represents the all-weld-metal analysis of E347-16 deposits as per AWS A5.4. The niobium content is the defining element that separates this welding rod from unstabilised E308L:

Element	C	Cr	Ni	Mo	Mn	Si	P	S	Cu
AWS A5.4 Spec Limits (wt%)	0.12 max	11.0 – 13.5	0.70 max	0.75 max	1.0 max	0.90 max	0.04 max	0.03 max	0.75 max
Typical Values	0.054	12.50	0.12	0.030	0.55	0.20	0.020	0.007	0.030

Nb content is specified as a minimum of 8 times the carbon content. With typical carbon at 0.055%, the minimum Nb requirement becomes 0.44%, which matches the typical deposit value. That stoichiometric ratio locks up all available carbon as NbC, leaving no free carbon to form harmful Cr₂₃C₆ at grain boundaries. Actual deposit chemistry varies with dilution, arc length, and welding parameters.

All-Weld-Metal Mechanical Properties of E347-16

These mechanical properties come from all-weld-metal tests as per AWS A5.4. Values represent the weld deposit, not the base metal:

Property	Ultimate Tensile Strength	Yield Strength (0.2%)	Elongation (%)	Charpy V-Notch Impact	Ferrite Number
AWS A5.4 Minimum	75,000 psi (520 MPa)	Not specified	Not specified	Not applicable	—
Typical Values	86,500–96,000 psi (596–662 MPa)	~58,000 psi (400 MPa)	~34.5%	Not typically specified	FN 5–10

Controlled ferrite content at FN 5–10 serves a dual purpose: enough ferrite to resist solidification cracking during welding, yet low enough to maintain toughness and corrosion resistance. The niobium addition raises tensile and yield strength slightly above E308L deposits through solid-solution and precipitation strengthening.

Base Metal Compatibility & P-Number Matrix for E347-16

WPS developers and welding engineers use this compatibility table to match E347-16 with approved base metals under ASME Section IX:

Base Metal	UNS	ASME P-No.	Notes
AISI 347	S34700	P-8, Grp 1	Direct match — Nb-stabilised
AISI 321	S32100	P-8, Grp 1	Standard electrode for 321 (Ti-stabilised E321 not commercially available for SMAW)
AISI 304	S30400	P-8, Grp 1	Use when PWHT above 400°C is specified
AISI 302	S30200	P-8, Grp 1	Similar to 304
AISI 304H	S30409	P-8, Grp 1	High-carbon grade for high-temp service
CF-8 Casting	J92600	P-8	Cast equivalent of 304
CF-8C Casting	J92710	P-8	Cast equivalent of 347 (Nb-stabilised)

E308L is preferred for ambient or moderate-temperature service below 400°C. E347-16 is required for service above 400°C, post-weld heat-treated weldments, or long-term thermal exposure in the 425–850°C sensitisation range. For dissimilar P-8 to P-1 joints, use E309L. E347 covers P-8 to P-8 dissimilar welds, such as 321 to 304.

Recommended Welding Parameters for E347-16 Electrode

The following parameters apply to E347-16 stainless steel stick electrodes. Standard austenitic stainless welding practices apply:

Diameter	Flat (A)	V & OH (A)	Voltage (V)	Polarity
2.4 mm (3/32″)	70–85	65–75	24–28	AC or DCEP
3.2 mm (1/8″)	85–110	80–90	26–30	AC or DCEP
4.0 mm (5/32″)	110–140	100–120	28–32	AC or DCEP
4.8 mm (3/16″)	120–160	110–130	28–32	AC or DCEP

Preheat is not required for 300-series austenitic stainless base metals. Keep interpass temperature at 175°C (350°F) maximum. Hold heat input below 1.5–2.0 kJ/mm for the best microstructure. Stringer beads are preferred, though moderate weave is acceptable because E347-16 retains controlled ferrite (FN 5–10). E347 weld deposits tolerate PWHT at 620–680°C without sensitisation. Re-dry electrodes at 300°C (570°F) for 1 hour before use if moisture exposure is suspected.

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Industrial Applications of E347-16 Niobium-Stabilised Electrode

Five major industries rely on E347-16 for the fabrication and repair of components exposed to sustained high temperatures or post-weld heat-treated service.

Reactor pressure vessel internals, primary coolant piping in 321/347 stainless, spent fuel pool liners, and steam generator components.
Process piping, heat exchanger tubesheet-to-tube joints, reactor vessels, and column internals in 321 or 347 stainless running at 400–700°C are welded with this stick electrode. Service environments include high-temperature organic acids, acetic acid, and hydrocarbon streams where unstabilised E308L deposits would suffer intergranular attack.
Tanks, piping, mixing vessels, and CIP systems built from 321 or 304 stainless steel.
347H superheater tubes, steam headers, and economiser coils operating in the creep range at 540–650°C are joined with E347-16.
Jet engine exhaust ducting, afterburner components, and gas turbine exhaust systems in 321 and 347 stainless steel rely on this welding rod.

Storage, Handling & Re-Drying of E347-16 Electrodes

Keep E347-16 welding electrodes in original sealed packaging at 15–25°C with humidity below 50% RH. Once opened, transfer rods to a heated holding oven at 100–150°C. If moisture exposure is suspected, re-dry at 300°C (570°F) for 1 hour. While E347-16 is not classified as a low-hydrogen electrode, moisture in the flux causes porosity and arc instability.

Limit re-baking to 3 cycles maximum. Exposure time caps at 4 hours in humid conditions and up to 8 hours in controlled environments below 50% RH. Store companion ER347 wire spools in dry sealed bags away from shop oil or dust. Sealed shelf life runs 3–5 years; once opened, consume within 6 months with proper storage.

How to Order E347-16 Welding Electrode from Nicorex Alloys

Provide the following 10 details to place an order for E347-16 welding electrode from Nicorex Alloys:

Electrode Type: SMAW Covered Electrode / Stick (E347-16)
Size: 2.5mm / 3.2mm / 4.0mm / 4.8mm x 350mm
Current Type: DCEP or AC — specify amperage per diameter
Welding Position: All Positions (1G–6G)
Material Grade: Nb-Stabilised Austenitic / UNS W34710 / AWS A5.4: E347-16 / W.Nr. 1.4551
Quantity: Pieces or cartons (1 kg / 5 kg / 10 kg / 20 kg)
Standard: AWS A5.4 / ASME SFA 5.4, EN ISO 14343, ASME Section IX
Additional Requirements: Nb stabilisation confirmation, IGC resistance, NACE compliance, PMI, heat/lot traceability
Documentation: MTC 3.1/3.2, PMI Report, Weld Metal Composition Report, TPI Certificate
Delivery: Domestic / International (specify destination)

Frequently Asked Questions

What is the Difference between E347-16 and E308L-16?

E308L-16 uses low carbon (≤0.03%) to resist sensitisation, while E347-16 uses niobium stabilisation with higher allowable carbon (up to 0.08%). E347 maintains intergranular corrosion resistance during PWHT and sustained service above 400°C, where E308L eventually sensitises.

Can E347-16 be Used to Weld AISI 321 Stainless Steel?

Yes. E347-16 is the standard SMAW electrode for welding AISI 321 (Ti-stabilised) base metal.

Is E347-16 Suitable for Post-Weld Heat Treatment (PWHT)?

Yes. This is the primary advantage over E308L. E347 weld deposits withstand PWHT at 620–680°C without sensitisation because niobium carbides remain stable at these temperatures.

What is the Niobium Content Requirement in E347-16 Weld Deposit?

AWS A5.4 specifies niobium at a minimum of 8 times the carbon content, up to 1.0% maximum. For a typical deposit with 0.055% C, the minimum Nb is 0.44%.

Does Nicorex Alloys Supply E347-16 with Nuclear-Grade Documentation?

Yes. Nicorex Alloys supplies E347-16 electrodes with documentation compliant to ASME Section III NCA-3800 requirements for nuclear applications.

What Shielding Gas does E347-16 Require?

E347-16 does not require external shielding gas. It is a flux-coated SMAW electrode. The rutile flux generates its own protective gas shield and slag blanket during welding.