Welder Qualification Test- 6G
In this article, we breakout the steps to pass the 6G position test according to AWS B2.1 6G using E6010 for open root and E7018 for fill and cap for the pipe welding certification.
The pipe welding techniques used, and the welding procedure is also identical to the AWS D1.1 and ASME Section IX welder performance qualification (WPQ) pipe welding certification. As per ASME Section IX, Qualification in the inclined fixed position which is 6G, shall qualify for all positions. So, welding a pipe in the 6G position covers all of the pipe welding as well as plate welding positions.
The 6G certified welder certification is not easy to pass and require lot of practice and training. But, we have see many new welders did perfect job and pass their certification in first attempt.
So, what you waiting for? Continue to upgrade yourself.
So, What is a 6G Pipe Welding Test?
A 6G pipe welding test as shown in the picture below is where the pipe is fixed at a 45-degree angle and welded in this fixed position. A fixed position means that once welding begins, the pipe cannot be rolled or moved. The welder has to weld all around the pipe in the same position. So, it basically covers flat, horizontal, vertical welding, and overhead in a single position. Hence considered one of the tough weld tests.
Why 6G test is so versatile?
If we compare a structural welding certification to pipe welding certifications we can see a major difference. Most of the structural welding is in one position and rod angle at one time i.e. welder will first weld either flat or horizontal or vertical. But, the 6G position is a combination of all of the structural and pipe welding positions, with a full changeover between them all i.e. for example 1G to 2G to 3G to 5G as the welder progress for the welding. Also, it’s a hard side and easy side, depending on if you are left-handed or right-handed!
Where to start before you go for a 6G Test?
Before moving to pipe welding, it’s always better to first master the plate or structural welding. Once, you got confidence in structural welding, go for pipe welding in 2G, then 5G and then practice 6G.
If you follow this, you will find 6G test much easier. Otherwise, you will struggle a lot.
AWS B2.1 SMAW 6G Pipe Welding Test Setup
- Welding Process: SMAW
- Position: 6G Fixed Position
- Weld Progression: Up
- Backing: No
- Current/Polarity: DCEP
- Root Opening: 1/16 to 1/8
- Groove Angle: 60 degrees
- Material/Specification: A 106
- Thickness: (pipe/tube): Groove (in) .280
- Notes: Sch. 40 Pipe
- Filler Metal Class: E6010Rt/E7018Fl
- Other Filler Metal Class: Rt 1/8, 3/32 Filler
Steps to pass a 6G test
Test coupon preparation and beveling
Prepare the test coupon bevel very carefully. A right bevel and root face is very important for good uniform full root penetration. Bevel can be prepared using a gas cutter, beveling machine, or even with a grinder. The below figure shows a typical weld bevel for a 6G test coupon.
Open Root Pipe Welding Techniques for the weld test
E6010 is a cellulose-type SMAW electrode. The arc of E6010 is very strong and there is no slag. A welding current of 60 amp to 75 amp is well suited for welding root run using 3/32’’ E6010 electrode. Watch the below video to learn about the technique for full penetration open root welding using the E6010 electrode.
Grinding during root run is recommended to make a good start point where the welding was stopped.
Hot Pass Pipe Welding Technique
The hot pass is the weld pass welded as the 2nd to 3rd pass on the pipe to cover the root weld. If done correct the hot pass will turn a flat root penetration surface to a convex, good looking one. If your root weld does not have enough penetration or even some suck back a good hot pass can fix that!
Hot pass or fill pass welding is done using an E7018 type electrode which is a low hydrogen electrode. Hot pass welding can be carried out using 1/8’’ or 5/32’’ electrode diameter. Avoiding grinding during a hot pass is recommended as many welding inspectors don’t allow grinding during hot and fill passes to judge the quality of the welders.
Pipe Welding Techniques for The Capping passes
Capping pass require usually weaving as width of the weld increase on the top of the bevel. Maximum 3 times of the electrode diameter weaving is allowed as per ASME Section IX and AWS D1.1.
Capping can be made with multipass welding using stringer beads although it require very good welding skills to blend the passes for a good appearance weld.
Tips for welding the capping runs
- Make sure to fuse the bevel’s edge on both sides by pushing the toe of the weld into it. This will help to avoid undercut.
- When welding multipass capping, overlap stringer beads from at least 25% to a maximum of 50%. The goal is for the weld to have a single flat profile when finished either by weaving or stringer beads.
- Only move forward and side to side with the electrode otherwise the weld will become rough.
- Don’t use high current when welding 3 O clock to 9 O clock as it might produce high weld face reinforcement.
Visual Inspection of the finished weld
- The weld shall be free from any arc strike near the weld on the pipe surface. Arc strike means welders lack good welding start practice. Usually, arc strikes are made inside the weld bevel or the previous weld so they become part of the weld.
- Clean the root from spatters for a good root profile view. The root shall be free from lack of penetration, excessive root penetration, suck back and lack of fusion, etc.
- The final finished face weld should show good workmanship with a uniform weld profile, no undercut or spatters. Minor undercut in small length can be accepted.
- The weld face reinforcement shall not be excessively high. Usually maximum of 4 mm is acceptable.
NDT or Bend testing of the test coupons:
To finally certify a welder, the welder test coupon must pass a volumetric NDT such as RT or UT or can be substituted by bend test as permitted into ASME Section IX or AWS D1.1.
Bend test shall be removed as shown in below figure.
Click here to learn about What is Bend Testing & types of bend test.