The Xiris Blog

SPC Measurements on a Tube Mill

Posted by Cameron Serles on Tuesday, April 10, 2018 @ 02:58 PM

Statistical Process Control (SPC) is the use of inspection data to determine the characteristics of a process, using techniques to find and remove abnormal variations in completed tubes.  Variable data is quantitative and is generated from actual measurements, such as the Mismatch, Bead Height, Deflection or similar measurements obtained from the Xiris WI2000 Weld Inspection system when it is placed right after the weld box on a tube mill. 

Variation is the difference between things that should be alike because they were produced under the same conditions.  Variation can be measured and groups of these measurements can be plotted as a frequency distribution, or histogram.  Since quality is a measure of conformance to specifications, poor quality results when variation falls outside the upper and lower specification limits.

2018_4_3 - SPC Data Logging Utility Display, Xiris WI2000.jpg

The SPC Data Logging Utility Display from a Xiris WI2000 system

 

SPC data can now be recorded and reviewed off line using the WI2000 measuring a number of parameters, including: 

  • Mean - the average of a group of values of a particular measurement.
  • Median -  the middle value of a group of ordered measurements.
  • Mode - the measurement occurring with the highest frequency.  This is the peak of the histogram.  In a true normal distribution, the mean, median and mode are all equal.
  • Range - the highest minus the lowest value in a set of measurement data.  This is a simple measure of the dispersion, or spread, in a set of data.
  • Standard Deviation - a measure of dispersion computed from the square root of the sum of the deviations from the mean, divided by the total frequency. 

Statistical process control uses the concept of subgroup sampling.  This is a method of data collection that considers a series of consecutive measurements together as a single group.  A typical subgroup size is five (5) measurements.  In order to smooth out the variability associated with an individual measurement, five consecutive measurements would be considered together as a representative sample. 

Xiris has implemented an SPC measurement logging capability to provide a way for fabricators to monitor their tube mills and identify abnormal variations in their completed tubes.

 

Topics: weld inspection, Tube and Pipe welding

Monitoring High Amperage Welding on Aluminum

Posted by Justin Grahn on Tuesday, March 27, 2018 @ 02:32 PM

Aluminum welding needs to be performed typically "hot and fast." When using automated welding equipment, it is very challenging to get the process parameters correct. To aid in automated aluminum welding processes, a weld camera can be used to monitor for process variations that could cause a poor weld, including:

  • Burnthrough: Higher thermal conductivity and lower melting point of aluminum alloys can easily lead to burnthrough. Even on thicker material, welders have to carefully monitor that welding current high enough to penetrate the weld joint adequately does not cause burnthrough.
  • Cracking: Aluminum TIG welds often have a tendency to crack if there is not enough filler metal to change the weld chemistry to make it less crack-sensitive.
  • Weld Shape: A good aluminum weld will be flat to slightly convex in shape. If welds are ropey or convex, it is usually an indication that not enough energy was provided to the weld and cold procedures or undersized equipment was used.
  • Heat Affected Zone: by monitoring the size and shape of the HAZ, operators can reduce how much the base metal melt, reducing the opportunity for stress cracking;
  • Shielding gas: In thick aluminum welding, monitoring shielding gas size, shape and color can indicate its chemistry. Altering the chemistry can vary the heat input, changing the weld root width penetration, and reduce porosity.
  • Weld discoloration: may indicate metal oxides are cooling outside of the shielding gas range on the base metal, increasing the possibility of contaminants.
  • Oxide layer: if oxide layer has not been adequately removed in the weld arc, contaminants could migrate into the weld, causing porosity or cracking.
All these phenomena can be seen by a trained operator when remotely monitoring the aluminum welding process with a welding camera. To achieve best quality of image, a monochrome weld camera can be used at low exposure rates to produce the best image because the aluminum weld arc is so bright, offering better contrast and dynamic range than a color camera.

 2018_3_27 - Monitoring High Amperage Welding on Aluminum with a Weld Camera

Image of Aluminum welding with a Monochrome camera,

at extremely low exposure

 

Topics: weld camera, Aluminum, High Amperage Welding

Watching a Rotating Cladding Process

Posted by Justin Grahn on Tuesday, March 13, 2018 @ 10:46 AM

Cladding material on to the inside surface of a pipe requires movement of the torch head relative to the pipe surface. This is done by either rotating the pipe, keeping the welding torch stationary, or by rotating the welding torch and keeping the pipe stationary. For longer sections of pipe, or for pipe that has already had a number of sections welded together, moving the pipe itself is not always practical. Instead, the weld torch must be rotated to perform the cladding operation.

To remotely monitor the cladding process, a weld camera can be mounted next to the weld torch, allowing operators to detect defects in the cladding process while they are happening and respond immediately with positional adjustments or even by tweaking the material inputs to the optimize the clad. While it is not too difficult when the torch remains stationary, it is more of a challenge when the torch has to rotate through many rotations to complete the cladding operation.

To solve this problem, the Xiris XVC-1000 and XVC-1000e weld cameras were integrated and successfully tested on a slip ring to transmit the power and electrical signals from the camera inside the pipe to an external computer. A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary device such as the external computer to a rotating device – the weld camera inside the pipe.

With the successful testing of the video transmission by slip ring, it is now possible to equip cladding machines that have rotating torches or carriages with a weld camera. This provides much better process monitoring in ways that were not possible previously as operators were forced to watch the cladding through a welding shield or helmet, trying to follow the arc around in circles as best as they could.

 

2018_3_13 - Watching a Rotating Cladding Process

The View from a Weld Camera as Transmitted over a Slip-Ring



Topics: Pipe Cladding, weld monitoring, Slip Ring

Watching a 1,000,000 Watt Plasma Arc!

Posted by Justin Grahn on Tuesday, February 27, 2018 @ 01:17 PM

Usually Xiris Weld cameras are used to monitor open weld arcs of many kinds of processes, including plasma welding processes, where the power settings are usually in the range of a few hundred Watts of power.

So imagine when presented with the challenge of monitoring a one million Watt plasma arc! This is exactly what Xiris was asked to do – mount a camera to see such a powerful arc as part of an industrial process. We were not sure how well the camera would respond to the plasma arc as it was so hot and generated such intense bright light that even the dynamic range of the XVC-1000 weld camera may not be sufficient to properly image it.

When setting up the camera, we had to mount the camera far away from the plasma arc, at about 6 ft. (2 m) away, while monitor the entire process in a completely different room. The plasma arc was so powerful that our camera would shake when the arc was activated. Even from a protected room, the noise that the plasma arc generated seemed like standing next to a jet engine.

We were happy to discover that, even with such a powerful light source, the Xiris XVC-1000 weld camera was able to capture clear images of the high-powered plasma arc. The images were good enough to see sufficient detail in the arc for research staff to analyze the behavior of the return arc remotely, without having to be close enough to the plasma source to create hazardous work conditions.

2018_2_27 - Watching a 1,000,000 Watt Plasma Arc

An Actual Image of a 1,000,000 Watt Plasma Arc!

 

Topics: weld camera, weld monitoring, Plasma

Xiris is Growing!

Posted by Catherine Cline on Tuesday, February 13, 2018 @ 11:33 AM

In 2017 Xiris saw business growth of more than 40% over the previous year. This growth was due in part to the large increase in automation throughout the manufacturing industry, an increase in metal additive manufacturing in the aerospace industry and a new focus on employee training, health and safety for welding processes.

North American Industry saw the highest number of robots delivered in 2017, with twenty-seven thousand delivered in the first nine months, according to Machine Design magazine. The largest installations of robots came from the automotive components and metals manufacturing markets with food and consumer goods close behind. The machine vision market also saw a growth rate of 14% in 2017 with 14% of those being vision systems.

The Xiris XVC family of weld cameras have become critical tools in advancing weld automation processes across the board, particularly in the growing markets mentioned above. The Xiris weld cameras become the eyes of the robot and enable operators to safely see the weld process from start to finish.

In order to keep up with this growth, Xiris is also expanding. We have added a number of new employees in all areas of the company. We now have a Sales Manager in Dusseldorf to address increased demand in Europe. We have also increased staff at our head office in Burlington in all areas of the business including software/hardware design and development, production and product support. With these added resources we feel well positioned to meet growing demands and look forward to continued growth and success in 2018 and the coming years.

Thank you to all our great customers and partners for a great 2017!

Xiris personnel.jpg

 

Topics: weld camera, welding automation, Machine Vision, Robotic Welding

Using Cameras When Welding Spiral Pipe Part 3: Post Weld Inspection

Posted by Cornelius Sawatzky on Monday, December 04, 2017 @ 03:16 PM

Following sub arc welding on the inside and outside of a helically welded pipe, the pipe must undergo inspection to be prepared for further processing or service in the field. This preparation step includes rigorous inspection and testing procedures, repair of defects, and application of anti-corrosion coatings before the pipe enters service.

 

Dec 4 - image 1.jpg

Post-weld Scarfing in helical sub arc welding

Traditionally, post-weld inspection is done manually by an operator who walks around the exterior of the pipe or crawls through it as part of an offline process. The operator is responsible for identifying any weld undercut, incorrect weld wetting angles, or insufficient or excessive weld bead material from the process.  It is not only time consuming, but it relies on the operator to be consistent to be able to catch all defects in the product.

A better solution is to use automatic inspection equipment such as the Xiris WI3000 weld inspection system, which can profile the entire weld bead after the flux has been removed or fallen away to detect problems sooner in the process.  Usually used as an inline inspection tool post-weld, the WI3000 can also be used to provide the operator with feedback to make corrections reducing additional defects while marking the location of a defect to expedite the repair process.

Dec 4 - image 2.png

Laser Bead Profile of a Weld Bead with a Too Steep Slope on the Right Side of the Bead

Information from the laser sensor is transmitted to a single image-processing system, allowing the operator to identify and control the welding parameters.   The end result is a better, more objective measurement of the weld bead inspection process in advance of use of the pipe in the field.

Xiris Automation offers a full suite of products for your helical sub arc welding (HSAW) process. From the control and quality assurance of the initial forming and tacking stage by the XVC-1000, through the remote monitoring of process parameters during full-seam sub arc welding by the XVC-S, and the post-welding and post-scarfing inspection by the WI-3000, Xiris provides operators with the tools they need to prepare the highest-quality products they can.

To learn more about how Xiris Automation’s full suite of turnkey solutions can improve the quality and yield of your HSAW manufacturing process, contact one of our technical specialists today.

 

Topics: High Dynamic Range, Tube and Pipe welding, submerged arc welding

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