Lincoln Chromet 9-B9 E8015-B8 — Overview
Lincoln Chromet 9-B9 is a low-hydrogen, low-alloy SMAW electrode classified to AWS A5.5/A5.5M E8015-B8, designed for welding conventional 9Cr-1Mo alloy steel (ASTM A335 Grade P9, ASME P-No. 5B) used in high-temperature petroleum refining, power generation boilers, and heat exchangers operating at elevated service temperatures. The B8 deposit chemistry provides approximately 8.0–10.5% Cr and 0.85–1.05% Mo in the weld metal to match the oxidation and creep resistance of the P9 base material. Unlike the newer modified Grade 91 (B91), conventional 9Cr-1Mo (P9) does not contain the vanadium-niobium-nitrogen additions, resulting in lower creep strength but simpler PWHT requirements. DC+ (DCEP) only; all positions. Available at WeldingMart as an authorized Lincoln Electric distributor.
Specifications
| AWS classification | AWS A5.5/A5.5M E8015-B8 |
|---|---|
| Alloy chemistry (deposit) | 8.0–10.5% Cr, 0.85–1.05% Mo (nominal) |
| Coating type | Low-hydrogen, basic |
| Polarity | DC+ (DCEP) only |
| Welding positions | All positions: 1G, 2G, 3G, 4G |
| Minimum tensile strength | 80,000 psi (551 MPa) |
| Minimum yield strength | 68,000 psi (469 MPa) |
| Elongation | 16% minimum |
| Typical current range | 1/8 in: 85–135 A | 5/32 in: 110–165 A | 3/16 in: 140–210 A |
| Available diameters | 1/8, 5/32, 3/16 in |
| Manufacturer | Lincoln Electric |
| Standards compliance | AWS A5.5/A5.5M; ASME Section IX P-No. 5B; ASME B31.3 |
Applications & Industries
- Petroleum refinery: Catalytic cracker, fractionation, and coker unit piping fabricated from ASTM A335 Grade P9 alloy steel where conventional 9Cr-1Mo composition is specified
- Power generation boilers: Boiler superheater and reheater tube systems operating at elevated service temperatures where P9 alloy is the specified material
- Heat exchangers and pressure vessels: Shell-and-tube heat exchangers in corrosive, high-temperature service where chromium content provides oxidation resistance
- Dissimilar metal joints: Welding 9Cr-1Mo steel to 2¼Cr-1Mo (P22) or carbon steel components using appropriate butter layers and documented WPS procedures
- Repair welding: In-service maintenance and repair of existing P9 components in operating refineries and power plants
Process Technology — How to Run E8015-B8
- Preheat: 300–400°F (149–204°C) minimum preheat for P9 alloy steel. Follow ASME B31.3 Table 330.1.1 or applicable code for the specific base metal heat and section thickness.
- Interpass temperature: Maintain above preheat minimum; do not exceed 600°F (315°C) maximum interpass to control microstructure.
- Post-Weld Heat Treatment: Required per ASME B31.3 for P-No. 5B materials — typical PWHT range 1300–1400°F (704–760°C) for 1 hour minimum per inch of thickness.
- Low-hydrogen technique: Use electrodes directly from holding oven at 250–300°F or from sealed packaging. Maintain heated quiver in the field; use within 4 hours of removal.
- Bead technique: Stringer or narrow weave beads; limit heat input per WPS. Wire brush and inspect each bead before depositing the next pass.
- Arc restart: Re-strike in front of the previous bead crater; back-step to fill the crater before proceeding. Chip and brush slag between every pass.
Storage & Handling — Low-Hydrogen Electrodes
- Before opening: Store sealed packaging in a dry ambient-temperature location (40–120°F / 4–49°C)
- After opening: Transfer immediately to a holding oven at 250–300°F (121–149°C). Use within 4 hours of removal or recondition at 700–800°F (371–427°C) for 1 hour per AWS A5.5
- Field storage: Use a heated electrode quiver. Do not leave exposed to ambient air overnight
- Reconditioning: Permissible once per AWS A5.5. Do not recondition electrodes showing visible coating damage or cracking
Frequently Asked Questions
- What is the difference between E8015-B8 (Chromet 9-B9) and E9015-B91 (Chromet 92)?
- E8015-B8 (Chromet 9-B9) is designed for conventional 9Cr-1Mo alloy steel (ASTM A335 P9, ASME P-No. 5B) without vanadium-niobium-nitrogen additions. E9015-B91 (Chromet 92) is for modified 9Cr-1Mo-V Grade 91 (P91), which includes controlled additions of V, Nb, and N for significantly higher creep strength. Do not use Chromet 9-B9 (B8) on Grade 91 applications — the alloy chemistry will not match the required deposit composition.
- What is E8015 vs E8018 coating type?
- Both E8015 and E8018 are low-hydrogen classifications. The "15" suffix indicates a low-hydrogen coating running DC+ only; the "18" suffix indicates a low-hydrogen iron-powder coating that can run on DC+ or AC. For most alloy steel applications in ASME code work, both are acceptable per the WPS. Chromet 9-B9 is the "15" (DC+ only) variant.
- What PWHT is required for E8015-B8 welds?
- ASME B31.3 and Section VIII require post-weld heat treatment for P-No. 5B (9Cr-1Mo) materials. Typical PWHT: 1300–1400°F (704–760°C) for 1 hour minimum per inch of weld thickness. Confirm specific requirements in your qualified WPS — PWHT temperature and time vary with base metal composition and section thickness.
- Does Lincoln Chromet 9-B9 require a holding oven?
- Yes. E8015-B8 is a low-hydrogen electrode — after the sealed packaging is opened, transfer electrodes immediately to a holding oven at 250–300°F (121–149°C). Use within 4 hours of oven removal or return for reconditioning. Hydrogen-induced cracking (HICC) is the primary risk when low-hydrogen electrodes are used without proper moisture control on alloy steels.
Browse Cr-Mo electrodes: Stick Welding Electrodes & Rods — or compare with Lincoln Chromet 92 E9015-B91 for modified Grade 91 applications.