6g Position Welding Review

Report Title: Evaluation and Procedure Qualification for 6G Position Welding (Pipe Welding) Report No.: WP-6G-2024-001 Date: [Insert Date] Author: [Your Name/Title] Subject: Analysis of Mechanical and Visual Properties of a 6G Inclined Pipe Weld

1. Executive Summary This report documents the procedure and results of a 6G position weld performed on a schedule [XX] pipe. The 6G position is defined as a fixed pipe inclined at 45°, requiring the welder to weld in all four positions (flat, horizontal, vertical, and overhead) within a single joint. The objective was to qualify the welding procedure specification (WPS) for critical structural and pipeline applications. The test piece passed both visual and radiographic inspection, meeting ASME Section IX and API 1104 standards. 2. Introduction Position welding is critical for field construction where pipes cannot be rotated. The 6G position is considered the most challenging certification for a pipe welder because the weld axis is fixed at a 45° angle. This requires continuous manipulation of the welding torch/stick to maintain proper puddle control against gravity. 3. Scope of Work

Base Material: [e.g., API 5L Grade B, Carbon Steel] Pipe Dimensions: [e.g., 6 inches (DN150) x Schedule 80] Bevel Configuration: Single V-groove, 37.5° included angle, 1.6 mm landing (root face) Root Gap: 2.5 mm – 3.2 mm Position: 6G (Fixed – Axis inclined at 45°)

4. Welding Parameters & Consumables | Parameter | Detail | | :--- | :--- | | Process | SMAW (Shielded Metal Arc Welding) / GTAW (Root) | | Electrode (Root) | E6010 (Cellulosic) – 3.2 mm Ø | | Electrode (Fill/Cap) | E7018 (Low Hydrogen) – 3.2 mm / 4.0 mm Ø | | Polarity | DC+ (Electrode Positive) | | Root Current | 75 – 95 Amps | | Hot Pass/Fill Current | 110 – 130 Amps | | Interpass Temperature | Max 250°C (480°F) | 5. Execution Procedure Due to the 6G geometry, the following techniques were employed: 6g position welding

Root Pass: "Keyhole" technique with E6010. The welder used a tight arc and a whipping motion to penetrate the root gap while fighting gravity on the overhead portion. Hot Pass: Ground flush to remove slag traps. High current to burn out any wagon tracks. Fill Passes: Weaving technique limited to 3x electrode diameter. The welder shifted body position four times around the pipe to maintain a consistent work angle (approximately 45° relative to pipe tangent). Cap Pass: Slight weave to produce a smooth crown, ensuring no undercut on the upper (12 o'clock) side of the incline.

6. Inspection Results 6.1 Visual Inspection (VT)

Reinforcement: 1.5 – 2.5 mm (Acceptable) Undercut: None > 0.4 mm (Per API 1104) Surface Porosity: None observed Profile: Convex, uniform toes Report Title: Evaluation and Procedure Qualification for 6G

6.2 Radiographic Testing (RT)

Result: Pass Findings: No linear indications, slag inclusions, or incomplete fusion. Minor scattered porosity (less than 1 mm) in the overhead 5 o'clock position, within allowable limits of ASME Section VIII.

6.3 Mechanical Testing (Destructive) If this was a qualification coupon: | Test Type | Result | Standard | | :--- | :--- | :--- | | Guided Bend (Face) | No cracks > 3mm | AWS B4.0 | | Guided Bend (Root) | No cracks | AWS B4.0 | | Nick Break | 100% Fusion, no slag | ASME IX | | Tensile Strength | 72,000 psi (Exceeds 60,000 min) | ASME IX | 7. Challenges Specific to 6G Position During the procedure, three distinct challenges were noted specific to 6G vs. 2G or 5G: The objective was to qualify the welding procedure

Gravity Asymmetry: Unlike 5G (horizontal pipe), the 45° angle means the puddle constantly wants to sag downhill, requiring a "sloped" oscillation pattern. Welder Ergonomics: The welder must adopt a kneeling or overhead stance for the lower quadrant, increasing fatigue. Penetration Consistency: The root opening had to be slightly tighter on the downhill side to prevent burn-through.

8. Conclusion The 6G position weld test piece met or exceeded all acceptance criteria for structural and pipeline welding. The welder demonstrated proficiency in transitioning between flat, vertical, and overhead welding planes within a single continuous weld. It is recommended that the welder be certified for 6G unlimited thickness under ASME Section IX, QW-452. 9. Recommendations