Engineering Review: Single Pulse Collaborative Arc Welding System – Istanbul, Turkey

Field Report: Implementation of Single Pulse Collaborative Arc Welding Systems

Location: Dudullu Industrial Zone, Istanbul, Turkey

This report details the technical deployment and performance evaluation of a Single Pulse Collaborative Arc Welding System within a high-mix, mid-volume manufacturing facility in Istanbul. The primary objective was to transition specific Carbon Steel welding operations from manual GTAW/GMAW stations to an integrated automated framework. Unlike traditional fixed automation, the focus here was on the synergy between human intervention and the precision of a Collaborative Arc Welding System.

1. The Shift to Automated Welding in the Turkish Manufacturing Context

The industrial landscape in Istanbul, particularly in the metal fabrication sectors of Tuzla and Dudullu, is currently facing a dual pressure: rising labor costs and a shortage of certified high-pressure vessel welders. Traditional Automated Welding—characterized by massive robotic cells, light curtains, and rigid safety fencing—is often non-viable for these workshops due to floor space constraints and the need for frequent jig reconfiguration.

The introduction of a Collaborative Arc Welding System addresses these constraints. By utilizing power and force limiting (PFL) sensors, we integrated the welding unit into the existing production line without the need for extensive safety enclosures. This allows the operator to work in tandem with the robot, handling part loading and tacking while the system executes the primary structural beads.

2. Technical Specifications: Carbon Steel Welding Parameters

The project focused on S235JR and S355JR grades of Carbon Steel, with thicknesses ranging from 3.0mm to 8.0mm. Carbon Steel welding in these thicknesses requires precise heat input management to avoid burn-through on the root pass while ensuring adequate fusion in the corners.

Single Pulse Waveform Optimization

We utilized a single pulse GMAW process to manage the droplet transfer. In Istanbul’s humid maritime climate, hydrogen-induced cracking is a minor but persistent risk if the base material isn’t stored correctly. The pulse profile was tuned to a ‘one drop per pulse’ (ODPP) regime. This reduces spatter compared to standard spray transfer, significantly cutting down on post-weld cleaning time—a critical metric in Automated Welding efficiency.

• Wire: ER70S-6 (1.2mm diameter)
• Gas Mix: 82% Argon / 18% CO2 (Local Turkish supplier standard)
• Peak Current: 340A – 380A
• Background Current: 80A – 110A
• Travel Speed: 35-45 cm/min

3. Synergy Between Collaborative Arc Welding and Automated Welding

The true value realized in this Istanbul field site was the technical synergy between the “Collaborative” nature of the hardware and the “Automated” nature of the process. In a traditional Automated Welding setup, if a part’s fit-up deviates by more than 0.5mm, the robot will likely weld off-seam, leading to a scrap part.

By using a Collaborative Arc Welding System, we implemented a “Human-in-the-Loop” workflow. The welder uses a lead-through programming method—physically moving the robot arm to the start and end points—which allows for real-time compensation for plate warping or poor fit-up common in heavy Carbon Steel welding. This hybrid approach maintains the speed of Automated Welding while retaining the cognitive flexibility of a human welder.

4. Field Challenges and Lessons Learned

Infrastructure and Power Stability

One unforeseen challenge in the Istanbul workshop was the volatility of the local power grid during peak industrial hours. Collaborative Arc Welding Systems, particularly those involving sensitive cobot controllers and high-frequency pulse power sources, are susceptible to voltage drops. We observed intermittent arc instability which was traced back to harmonic distortions from neighboring heavy machinery.

Lesson Learned: Always install a dedicated industrial voltage stabilizer and ensure proper grounding of the Collaborative Arc Welding System to prevent signal interference in the encoder cables.

Addressing the ‘Fit-up’ Gap

Manual Carbon Steel welding is forgiving; a human welder sees a gap and slows their travel speed or weaves the torch. Automated Welding is inherently rigid. During the first week, we saw a 12% rejection rate due to root gaps exceeding 1.5mm.

Lesson Learned: We recalibrated the upstream laser-cutting parameters to tighten tolerances. Additionally, we programmed a simple ‘weave’ function into the Collaborative Arc Welding System’s software to accommodate slight variations in joint geometry, effectively mimicking the human ‘thumb-flick’ technique.

Shielding Gas Consistency

Istanbul’s industrial gas supply can vary in moisture content. When welding Carbon Steel, even minor impurities lead to porosity in the pulse regime.

Lesson Learned: We integrated an inline gas flow meter and a secondary moisture trap. For Automated Welding to be successful, the input consumables must be as consistent as the robotic pathing.

5. Quantifiable Outcomes

After a 60-day implementation period, the data from the Istanbul facility showed significant improvements across three key KPIs:

Arc-On Time Efficiency

Manual welding stations typically averaged an ‘arc-on’ time of 25-30%. The Collaborative Arc Welding System increased this to 65%. Because the operator prepares the next jig while the robot finishes the current Carbon Steel welding cycle, the ‘dead time’ between parts was nearly eliminated.

Consumable Reduction

By switching to a controlled Single Pulse Automated Welding process, wire consumption dropped by 14%. This was attributed to the elimination of over-welding. Human welders tend to over-deposit metal “just to be safe,” whereas the collaborative system follows the exact calculated fillet size required for the S355JR structural specifications.

Skill Upskilling

A notable sociological outcome in the Istanbul shop was the transition of “welders” to “robot operators.” The staff, initially skeptical of the Collaborative Arc Welding System, found that it removed them from the most ergonomically taxing and hazardous positions (extreme heat and UV exposure), allowing them to focus on weld quality inspection and process optimization.

6. Technical Conclusion

The deployment in Istanbul confirms that for mid-sized Turkish enterprises, the path to Automated Welding is not through full-scale industrial robotics, but through the phased integration of Collaborative Arc Welding Systems. For Carbon Steel welding, the Single Pulse GMAW process provides the necessary balance of penetration and aesthetic quality while minimizing the thermal distortion of the workpiece.

The success of these systems depends less on the robot itself and more on the integration of the welding power source’s pulse logic with the cobot’s motion control. Future installations will focus on integrating AI-based vision systems to further automate the seam-tracking process, reducing the need for manual TCP (Tool Center Point) adjustments even when part fit-up is sub-optimal.

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Senior Welding Engineer: [Field Signature]
Date: October 2023
Project Ref: IST-CARBON-7700