StarBlaze Prime 7018–A1 H4R
AWS A5.5: E7018–A1 H4R | ISO 3580-A: E MoB 3 2 H5
H4R Grade | Mo/Cr-Resistant Welds | Boiler & Pipe-Ready
A low hydrogen, moisture-resistant iron powder electrode designed for creep-resistant steels containing 0.5% Mo and 0.5–1.0% Cr. Suitable for high-integrity welding in boilers, pressure vessels, cement kilns, cast steels, and structural components operating at elevated temperatures (up to 525 °C). Delivers smooth arc behaviour, excellent weld bead appearance, and radiographic-quality joints across all positions.
Available Packs:
Dimensions:2.50 mm x 350 mm, 3.15 mm x 450 mm, 4.00 mm x 450 mm, 5.00 mm x 450 mm
Pack Sizes: 2.5 Kg Pouch, 5 Kg Box
Master Box: 20 Kg, Customisable packaging available on request
- Suitable for creep-resistant Mo and Cr-Mo steels up to 525 °C
- Radiographic-quality welds on cast steels, pressure vessels, and pipe spools
- H4R grade – excellent resistance to moisture absorption
- Excellent for boiler, kiln, and structural fabrication with thermal stress exposure
- Reliable performance on steels with ≤0.5% Mo and 0.5–1.0% Cr
- Can be used as-welded or stress-relieved at 620 °C for 1 hr
- Pressure Vessel & Boiler Fabrication
- Cement Kiln and Chemical Furnace Construction
- Cast Steel Machinery Frames
- Pipe Systems and Steam Lines
- Structural Welding of Creep-Resistant Steels
- Manual Metal Arc Welding (MMA / SMAW)
- Operates on both AC and DC+ polarity
- All-position welding (1G, 2F, 3G, 4G, 5G)
- Designed for welding of pressure components with Mo/Cr alloying
- Suitable for pipe welding, vessel shell joints, and heavy-wall castings
- Base materials include:
• EN 10028-2: P235, P265, P295, P355, 16Mo3
• EN 10216-1/2: P235, P275 | EN 10213-2: GP240R, G20Mo5
• EN 10025: S235, S275, S355 | Ship steels A–E - Re-drying: 300–350 °C for 1 hr if required
- Excellent impact strength at +20 °C (Charpy ≥ 100 J as-welded; ≥150 J stress-relieved)
- Good ductility after post-weld heat treatment
- Conforms to ISO 3580-A specifications for creep-resistant electrodes
Product Details
Typical Weld Metal Chemical Composition (%)
| C | Si | Mn | Mo | P | S |
| 0.07 | 0.40 | 0.80 | 0.50 | 0.020 | 0.016 |
Typical Mechanical Properties As Welded (All Weld Metal)
| Yield Strength
Rp (N/mm2) |
Tensile Strength
Rm (N/mm2) |
Elongation
A5 (%) |
Charpy Impact Value
ISO-V J +20°C |
| ≥ 420 | 550-650 | 24 | 100 |
Typical Mechanical Properties Stress Relieved (620°± 15° for 1hr.)
| Yield Strength
Rp (N/mm2) |
Tensile Strength
Rm (N/mm2) |
Elongation
A5 (%) |
Charpy Impact Value
ISO-V J +20°C |
| ≥ 420 | 520-620 | 26 | 150 |
Recommended Welding Parameters
| Diameter (mm) | Amperage Range (A) |
| 2.50 | 60-90 |
| 3.15 | 100-140 |
| 4.00 | 140-180 |
| 5.00 | 180-230 |
