The Xiris Blog

Lighter wall mild steel pipe production requires bead height monitoring for bead ripple. Bead ripple is a condition sometimes associated with a weld process that is too hot and may result in longitudinal weld cracks.  Bead ripples appear along the length of the weld bead as undulations with measurable differences in height by as much as 1/8” (3 mm).  Often the height of the bead ripple on a welded pipe is a function of the heat that has gone into the weld process:  the higher the heat, the greater the height of the bead ripple. In most applications, a weld bead should have a smooth, consistent height as an indicator of a stable weld process.

An image of a weld bead with bead ripple

In some applications, a weld bead ripple can be desired, such as in certain coated steel products. This ensures that all contaminants from the area of the weld have been squeezed out, preventing potential inclusions from occurring in the weld bead, which would result in compromised weld quality.

By measuring the bead height on a weld bead over a period of time using a laser based triangulation system , an indication of the smoothness of the weld bead can be made.  By calculating ongoing historical statistics of the head height (e.g. min/max, average, standard deviation), an indication of smoothness of the weld bead or bead ripple can be made.  Tolerances of the amount of smoothness or ripple can be set to match the process and when exceeded, an alarm can be set.

 Measuring the weld bead height over successive images can detect bead ripple over time

Fuel line tubing is typically manufactured on an ERW welding mill similar to traditional seam welded tubing.  Once the tube has been welded, it moves down the mill for further in-line processing that may include reducing, sizing, annealing and coating processes to meet the customer’s needs.

Fuel line tubing must be perfectly round in order to create a good seal when compression fittings are applied to it. The tube surface must be free from longitudinal scratches, grooves or beads in order to prevent a leak path from developing at the interface point of the fittings.

Immediately after the fuel line tube has been welded and before any further in-line processing is done, the weld bead must be scarfed (the process whereby the weld bead is cut off with a knife).  Unfortunately, the scarfing process can be the primary contributor to creating a leak path on a compression fitting because:

1. Insufficient scarfing can leave a small portion of the weld bead protruding from the     surface of the tube. This may be on either one or both sides of the weld bead where scarfing tool positioning is critical.

Insufficient Scarfing

2. Excessive scarfing may look perfectly round to the human eye however a non-uniform wall thickness may be lurking below the surface. What is not always apparent and usually only observed during thorough end cut inspection is a thinned portion of the tubing wall that may compromise the integrity of the tube. The reducing process applies enough external force to the tube that the tube may buckle or collapse, causing a deep surface groove.

Excessive Scarfing

3. A mismatched setup may also be a contributor to a non-uniform wall thickness. The scarfing tool may cut the bead on the outside diameter so that it looks perfectly round to the human eye, disguising the compromised wall thickness below the surface. Sufficient mismatch conditions will most certainly cause the tube to split on end forming later in the fabrication process.

Mismatched Defect, Post Scarfing

The Xiris WI2000/3000 Weld Inspection System uses laser-based imaging techniques to continually monitor the scarf zone for any variations in the scarf height, seam mismatch and possible scarf tool wear or chips that may cause a longitudinal line on the tube. By detecting and responding to these conditions proactively, a mill operator is able to reduce the chance of a leak path on the tube and avoid an unplanned stoppage to the mill due to a tube collapse during the reducing process.

For more information on how a Xiris Weld Inspection System can enhance your scarfing processes visit Xiris.com 

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Additive manufacturing is an increasingly attractive technology that has in recent years graduated from a basic prototyping technology to one capable of producing large volumes of highly intricate part geometries in a wide range of materials. Of particular interest is the ability to produce complex geometries from industry grade metals for use in several fields including aerospace, biomechanics, and mold and die.

ASTM defines three subfamilies of additive manufacturing that are currently able to process metals: direct energy deposition, powder bed fusion, and sheet lamination. These families differ in their setup of feedstock material but all employ a directed energy source such as a laser or electron beam to process it. These laser additive manufacturing processes are characterized by rapid melting and solidification of subsequent layers in a tightly controlled environment.

Due to the repeated melting and solidification of layered material, parts undergo a complex thermal history and present a set of unique thermo-physical and metallurgical challenges. The most common defects seen in the laser additive process are a result of difficulties with maintaining a consistent melt pool caused by insufficient/excessive heat, oxidation, or contamination of the melt pool. The resulting micro-porosity in the build commonly propagates fatigue cracking in finished parts.

 

SEM image of fatigue cracking in stainless steel created by selective laser melting [1]

Introducing a Xiris high dynamic range weld camera during the manufacturing process allows the operator to see exactly what is happening during the laser additive manufacturing process, namely how the laser keyhole and melt pool are interacting with the surrounding material and previous layers. With such a camera, the size, shape, and consistency of the melt pool can be directly observed making critical problems such as an uneven melt pool, unfocused or unsuitable laser power, misalignment of the powder supply, or material powder contamination easy to identify and correct.

By determining the root source of these problems, a better understanding of build failure can be obtained and potential issues can be identified before they continue through the entire production process. This is especially useful for products that contain internal cavities or other features that are difficult to inspect post-build. On average, one quarter of the total time required to complete a laser additive manufacturing build is spent on the post-build inspection. The Xiris weld camera provides increased confidence in the quality of your components and can reduce the need for post-build inspection or destructive testing.

Laser  Additive Manufacturing – Steel – Process Monitoring

For more information on how Xiris Weld Cameras can enhance your laser additive manufacturing processes visit Xiris.com 

You can visit our

 WELD VIDEO LIBRARY

for dozens of examples of the camera in action. 

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References: [1] Li. R. et al. Densification behavior of gas and water atomized 316L stainless steel powder during selective laser melting. Applied Surface science. 2010. 256(13) pp. 4350-4356. 

Electromagnetic interference (EMI) that is generated by high frequency weld equipment can often play havoc with other welding equipment, such as cameras, by creating electromagnetic induction in the circuitry of the cameras.  Often the electrical disturbances that occur create a noisy camera image, interrupt image data acquisition or generate continuous lines running through the image. In xtreme cases, it can stop the cameras from functioning altogether.

 

The Xiris XVC-1000e Weld Camera

During extensive testing in the field, Xiris XVC weld cameras have proven themselves to be immune to the EMI that is generated by high frequency weld equipment.  EMI immunity has always been a problem identified by the industry when using cameras, so Xiris took this into consideration when designing the XVC camera family.  The camera is an all digital design, rather than the analog design common on most other weld cameras.  The result is that many problems resulting from outside interference are eliminated, allowing for excellent image stability and cable lengths of up to 100 m.  As part of that design, the camera housings have been extremely well shielded and grounded, eliminating any stray electrical noise.

The XVC weld cameras were extensively tested during the design/build process whereby extreme ranges of frequencies and power levels were used, including some of the harshest welding conditions, such as high power GMAW welding tests, with power approaching 1000A.  During those tests, the XVC weld camera cables were stretched parallel to welding power lines, wrapped around welding power lines and laid on/over/in grounded equipment, all without significant degradation of the camera image.

The camera has been tested to the EN 61326-1:2006 standard which includes the following tests:

• Electrostatic discharge
• Radiated RF Immunity
• Electrical Fast Transients
• Surge Withstand
• Conducted RF Immunity
• Magnetic Field Immunity
• Voltage Dips
• Short Interruption
• Harmonic Current Emissions
• Voltage Fluctuation and Flicker

The Xiris XVC weld camera is now widely used on manufacturing floors running in some of the most challenging welding environments, including alternating polarity GTAW, high powered GMAW and Plasma processes, providing clear images to operators as far as 100 m away from the weld head.

For more information on how Xiris Weld Cameras can eliminate EMI interference and enhance your weld processes visit Xiris.com 

You can visit our

 WELD VIDEO LIBRARY

for dozens of examples of the camera in action. 

Don't miss any of our amazing videos! Sign up to receive the Weld Video of the Month 

 

 

Large Pipe Fabrication

Welding large pipes using either Submerged Arc or Open Arc welding processes may pose a number of problems, such as:

• poor alignment of torch to seam
• improper levels or placement of shielding gas or flux
• improper joint preparation
• jammed wire feeders
• wrong welding power levels

to name just a few.

 In order to avoid these problems and ensure the highest possible quality, welding processes must be monitored closely.  When automated welding processes were first introduced, fabricators stationed an operator in a chair atop a welding machine, such as a column and boom welder, to visually monitor the welding process directly.  Surprisingly, this is still a widely used approach to weld monitoring!

 

An empty chair waiting for the operator….

Even today, there are fabricators who are unfamiliar with automated inspection process and are forced to place an operator on a chair high above the welded pipe to monitor the welding process.  This is a health and safety problem waiting to happen!  Not only does the operator face fume inhalation, they risk injury from moving equipment, inadequate protection and dangerous heights.

Can you see the Operator monitoring the process?

In addition to the safety concerns, work breaks are a major drain on productivity.  Just think of the production time lost while moving the gantry robot or hoisting equipment down so that the operator can safely exit the equipment at ground level, not to mention the idle time until the operator returns to their position.

Or Here?

A Better Solution

The better solution is to use a remote monitoring weld camera installed at the weld head that can be viewed from as far as 100 m away.  Operators are on the production floor, removed from the welding process but still able to see all the details of a welding process.   Watch the video below, created by LJ Welding in Edmonton, Alberta, Canada, for an excellent demonstration of how weld cameras are being used in the field:

 

 

You can visit our

WELD VIDEO LIBRARY

for dozens of examples of the camera in action. 

For more information on how Xiris Weld Cameras can enhance your weld processes visit Xiris.com or REQUEST A DEMONSTRATON 

Don't miss any of our amazing videos! Sign up to receive the Weld Video of the Month 

Upgrade Your View!

This isn’t the first time Xiris has run into a duct-taped welding shield and it won’t be the last.  A manufacturing company, welding high quality products on a seamer has recently made some major upgrades.

From this:

To this:

What other single upgrade can so easily and cost-effectively increase quality, raise productivity, reduce health and safety risk, and improve working conditions for your operators?

A Xiris Weld Camera can be retrofitted on virtually any seamer in minutes.

Visit our

WELD VIDEO LIBRARY

for dozens of examples of the camera in action. 

For more information on how Xiris Weld Cameras can enhance your weld processes visit Xiris.com or REQUEST A DEMONSTRATON 

Don't miss any of our amazing videos! Sign up to receive the Weld Video of the Month