Mastering Metal Grades for High-Performance Automated Welding
Automated welding has come a long way in recent years. One of the most exciting recent developments comes from Dextall, a building material technology company, who’ve launched a robotic welding platform that produces structural parts three times faster than before. But to get the most out of robots, you have to choose the right material grade. Every metal, whether mild steel, titanium or aluminium, comes with its own unique characteristics that need specific settings to achieve perfect results every time.
Reliable mild steel grades for robotic welding
Mild steel, or low carbon steel, is the most common material used for automated welding. It has a carbon content of under 0.30%, which makes it strong enough for structural work but still plenty malleable. S355JR is the go-to grade for construction and machinery. Robots can get to work without having to pre-heat for thinner sections (which is thanks to the metal’s low carbon content), but a little programmed preheating to around 100°C will give better results when welding thicker plates.
S355JR is perfect for anything that needs to be extremely strong without too much extra weight. But S275JR is a cheaper alternative for automated frame and beam production or any welds that don’t have to be so tough. Both S355JR and S275JR work with robotic MIG/MAG and TIG because they give the robot a smooth and steady arc and cool down without any fuss. Robots can therefore work quickly with mild steel without it going brittle or cracking which isn’t the case with more sensitive metals.
Titanium grades and the need for total shielding
What metal’s just as strong as steel but only half the weight? Titanium. It also doesn’t corrode. It’s for these reasons that titanium’s an excellent material for welded parts in industries like medical, aerospace, chemical processing, and marine. Most grades of titanium (there are over thirty) are weldable whether by machine or by hand, but commercially pure titanium (which contains 98-99.5% titanium) does the job best.
Commercially pure titanium is available in grades 1-4. Grade 1 is the purest and easiest to bend and shape. The metal gets stronger with each grade, but at the same time becomes more rigid and harder to work with. Any filler wire used typically should also be the same grade as the base metal so the finished weld is just as strong and flexible as the rest of the part. This is the case for both manual and automated welding. Titanium wire near me in commercially pure grades will help you achieve a successful weld.
Automated titanium welding usually has to be done in a “glove box” environment where it won’,t be exposed to oxygen (otherwise it’ll become fragile and brittle). The box is filled with argon to keep any oxygen out. This is especially important if you’re working with Grade 5 titanium to make aircraft parts which will end up failing if there’s any degree of brittleness. Normally a human welder can adjust the trailing shield by hand so that the titanium will stay protected by argon the whole time until it’s cooled, but a robot can’t yet do this with the exact precision needed. So the glove box really is a must in automated welding to keep the metal silver and strong.
How robots clean and weld aluminium (Grade 6082)
Aluminium is very light (around one-third the weight of steel) and doesn’t rust, which is why it’s used in all sorts of industries from automotive to aerospace. Grade 6082 is probably the most common aluminum of choice for structural projects, but it is a bit more sensitive to heat (as really all aluminum is). Robot welders work very well with 6082 because they can keep up with how fast metal melts and hardens. Otherwise, it’s easy to end up with a weak or lumpy weld if you linger just a second too long. Another issue with 6082 (and other aluminum alloys) is that they can develop an oxide layer on the surface which gets in the way of welding. Robots can easily be programmed to “clean” this off using electrical currents, so the metals actually fuse together properly during the weld.
Matching up metal grades with the right robotic settings is the key to easy automated welding. Get this right and you’ll get strong and professional welds every time.
