Good looking tig welds cracking

Hi, i did some tig welding practice today on steel. The 70s6 and the 3 are cracking the worse, the 70s2 seems better but will still get an occasional crack. This layer has to be removed before you can get a good weld. Some tips for making beautiful looking tig welds on any material. Both solidification cracking and hot cracking refer to the formation of shrinkage cracks during the solidification of weld metal, although hot cracking can also refer to liquation cracking solidification cracks can appear in several locations, and orientations, but most commonly are longitudinal centreline cracks coincident with the intersection of grains growing from opposite. But my first task is to establish the relative amount of grayness exhibited. Weld cracking several types of discontinuities may occur in welds or heat affected zones. Pure aluminum rods are necessary for tig welding aluminum using direct current. I also have some cross bracing pieces of 2 12 x 316 flat bar.

I have managed to make welds with my oa rig that survive the visehammer test but i would like to get some pointers on what good welds look like. Tig welding requires good handeye coordination and practice. It offers the best results with strong clean visually appealing welds. It is another arc welding process that uses a nonconsumable tungsten electrode to produce the weld. Can you spot the difference between a good and bad weld. If the tig is a little underpowered use a torch to. Oxyfuel welding and cutting, oxyacetylene welding, oxy welding, and gas welding. Use features like bookmarks, note taking and highlighting while reading things you need to know about tig welding.

When you need deep penetration into thick aluminum, direct current penetrates better and delivers a better weld. These occur at the end of the welding process before the operator finishes a pass on the weld joint. The welds always look dull and as if they are covered with some dark gray, matt finish. The result is a goodlooking weld bead, as seen in figure 5b. Understanding weld cracking, its causes, consequencesand. When tig weld cracks, the deformity can jeopardize the integrity of the weld and cause delays, downtime, and severe frustration. And he shows why the best place to start is by understanding hot cracking and cold cracking. Just because a weld doesnt look good doesnt mean its bad. Why using a tig welder for welding steel to copper can be difficult. In this video i go through the basics of tig welding aluminium before welding up a crack in my boat the green machine. We frequently get questions about why a customers welds are not shiny like they see in the pictures, especially with tig and mig processes.

Use a circular motion and a whip action to prevent the weld puddle from spilling away from the weld. Gas tungsten arc welding really requires tight fitup because you need to develop the weld pool and establish a bond between the two sides before you add filler metal fig. Hydrogen enters the weld through the atmosphere, filler metals, shielding gas or mill scale on your base material. Fig 2 here are two gtaw tig welds side by side made on a 6061t6 base plate. Can be done with mig, tig, or arc welding machines. Preventing cracks in aluminum welds lincoln electric. Tig welders are considered the most precise welders available and are the welders most suited for welding exotic combinations of metals, or metals with disparate melting points. Use features like bookmarks, note taking and highlighting while reading everything you need to know about tig welding. It handles the properties of aluminum well and makes nice looking welds. However, with all welds tests must be run in order to determine adequate penetration. The two steels have similar mechanical properties, but a508 class 3 has a lower cr content and a higher manganese content. The edges of the weld bead should have a smooth transition into the base metal without undercut a defect that appears as a groove in the parent material. The temperature is too hot while welding and is allowed to cool too quickly. But all of this comes with a very serious learning curve.

Everything looks great after grinding and polishing the weld smooth,but after pressure testing to 3500 psi with water in the tube,i keep getting hairline cracks allowing water seepage. This is why your tig welds crack with 3 solutions welding. Stress cracks in aluminum are caused by cooling and contraction. Help cracking tig welds miller welding discussion forums. Details of how to avoid solidification cracking in ferritic steels are given in the best practise guide on fabrication cracking mechanisms. Thankfully, as with any part of the welding process, you can not only understand why your tig welds crack, but you can also learn solutions to help your welds to stop cracking. Alternating current is the standard for tig welding aluminum with good reason. Welds look uniform and getting penetration but im getting small cracks riding down the center line of the weld, not along the edges, but directly in the middle running the length of the weld. Match the tungsten electrode size with the collet size. When tig welding one hand is used for holding the tig torch that produces the arc and the other hand is to add the filler metal to the weld joint. Use dcstraight polarity dcen for steel and stainless.

I could understand it taking that long if theres cooling times and a specific weld procedure where more than half the time theres no welding going on, but even then with 5pieces you can keep a rotation that keeps them all pretty cool and you dont really stop welding. Particular care is necessary when tig gtaw welding on thin sections of this type of material. Unlike stress cracking in steel welds hydrogen isnt a factor as theres no hydrogen in aluminum. And it is one of the best ways to learn how to tig weld better. Defects imperfections in welds reheat cracking twi. Looking at your material certs is a wise first step. But, fillets welds without filler, especially if they are restrained in a fixture may be the culprit. Good process for thin metal very clean process producing good looking welds. You can easily fix crater cracking issues by continuing to feed filler rod while slowly reducing current at the end of a weld. Can you guys post pictures of what you consider good welds and offer a brief commentary for them to splain to a novice why the weld is good. The centerline crack shown on this fillet weld is of the result of low. For haz hydrogen cracking to occur, it is necessary for the hydrogen to migrate into the heat affected zone, which takes time. Check out this great resource from lincoln electric explaining in greater depth. I was expecting shiny looking welds with brownishbluish haze here and there, just like what i see in jodys videos.

Tips on how to weld cast iron uncatastrophically make it. I often find when i weld sprockets to hubs the weld always ends up with a crack in it. Despite its diminutive stature, it goes beyond tig welding and is capable of some stick welding as well. Lack of uniformity, cracks down the middle of the bead. Im use 2% thoriated 332 tungsten, argon set to 15 cfh, 332 er70s2 filler rod and amps set to the recommended 75 amps on the chart for metal thickness. Any how, they require 4 tubing cages properly braced with at least, good looking welds bird poop not allowed. However, after getting further into it, and welding some of the cross pieces in, i noticed some of the welds starting to crack at the end. You can easily fix crater cracking issues by continuing to feed filler rod while. Takes less time to learn than tig, faster for production work, less expensive than tig. Stainless steel cracks welding tips and tricks tig. Note that some tig welders feature a crater control function that automatically reduces the current at the end of a weld. Weld cracking refers to a depression left at the termination of a weld where the weld pool is left unfilled.

Unless it is was machined in the last day or two, all aluminum is coated with a thin layer of oxide that will ruin tig welds. Whereas there are acceptable limits for slag inclusions and porosity in welds, cracks are never acceptable. While a copper to steel weld requires a filler metal, some tig welds do not even require a filler metal. Oct 15, 2008 but, fillets welds without filler, especially if they are restrained in a fixture may be the culprit. Can tig welder repair or fix a not so good looking mig weld. Save the tig for pretty work, use the spool gun for the type of work you are doing. Thankfully, as with any part of the welding process, you can not only understand why your tig welds crack, but you can also learn solutions to.

I am using a tig at 55 amps on a 115 circut with 17 cfh of argon. Both types of cracks, even when small, can prevent welds from meeting code requirements and can eventually lead to weld failure. Looking for a reliable tig welder from a reputable brand that wont break the bank. Stainless steel cracks welding tips and tricks tig, mig. Welds crack for many reasons, including the following. In addition, weld may crack in the weld metal or in the base metal adjacent to welds metal, usually in the heataffected zone. Sep 11, 2017 how can i tell a good weld from a bad weld. Nov 28, 2018 welds made in aluminum experience two types of cracking. I am using tig, 332 rod, about 1720 cfm argon with 332 4043 filler. Spatter, undercutting, visible lack of fusion, and cracking. The top weld was deposited with no filler alloy, and. A goodlooking weld is clean and is the same color as the base metal, both inside and out. I like to use 308l but there are a lot of other options out there that work just fine. Knowing the basics behind why cracks happen, a welder can prevent those cracks.

There are 5 components to making a strong mig weld. How to tig weld better welding tips and tricks tig. We had several rollovers, end over end, and sideways, and with 106 cars entered, and at least 106 diffrent non professional welders, no cages let loose. Welds may contain porosity, slag inclusions or cracks. Theres a lot more to welding than just melting two pieces of metal together. You can also use 5356 rods, but the welds tend to be rough and wont look good. A good tig welder can create incrediblelooking welds that are very strong. When the weld pool cools and solidifies, it needs to have enough volume to overcome shrinkage of the weld metal. Reinforcing a welding repair is definitely needed if the crack is in a location where you cant prep its surface for welding, says. Tig tungsten inert gas welding is comparable to oxy acetylene gas welding and needs a lot more expertise from the operator. Preventing crater cracks in gas tungsten arc welds i. Well cover stress cracks first and then move on to hot cracks.

Apr 24, 2020 tig welding requires good handeye coordination and practice. All the students i questioned used er70s6, and used both tig and mig. Because of the low hydrogen deposit, these electrodes have an advantage for high strength pipes susceptible to hydrogen cracking. The overriding cause of solidification cracking is that the weld bead in the final stage of. Welding is actually a complicated process, and different methods are used on different types of metal. The miller welders channel provides the tips and techniques you need to tackle even. The best electrodes for tig welds with direct current are 2% lanthanum. Fillet welds are usually designed so that no grinding is needed sometimes it is prohibited, such as in some roll cage applications, because of the risk of thinning the throat too much if there are points of insufficient penetration into the root, but the primary reason isnt strength, it is cost.

You need a good ground, the right welding gas, the proper settings on your welder, the correct wire, and decent skills to lay a good bead. Download it once and read it on your kindle device, pc, phones or tablets. So below well learn about the 7 most common welding defects, their types, causes and remedies. Hi, im having troubles welding 1117 to 1018 with the tig process. Defects are common in any type of manufacturing, welding including. This visual guide will help you learn about 10 common tig welding mistakes as.

What separates tig welding from most other welding processes is the way the arc is created and how the filler metal is added. Looks like fairly everyday work to me, 12hrs to weld 5 of those is long. Unfortunately, it has also gotten a reputation for being weaker than other methods of welding. How to solve 10 common tig welding problems guide millerwelds. Today any weld shop welding stainless should look first at the worlds best process for stainless and all alloy gage welds, its. Most forms of weld cracking result from the shrinkage strains that occur as the weld metal cools. Apply a compressive force on the welded joint during welding to counteract the cracking mechanism. The most serious cracking problem with nickel alloys is hot cracking in either the weld metal or close to the fusion line in the haz with the latter being the more frequent. This of course can be caused by a number of things.

For example, a 508 class 2 is known to be particularly susceptible to reheat cracking, whereas cracking associated with welding and cladding in a508 class 3 is largely unknown. The width of the bead should be consistent and have an attractive face surface profile. All welds can be susceptible to solidification cracking. Dont use alloy rods or other metals for dc welding. If the contraction is restricted, the strains will induce residual stresses that cause cracking. The gray is caused because the metal is too hot after the shielding gas is removed from it and the weld has absorbed impurities from the atmosphere. Information on certain aspects of avoiding solidification cracking in a variety of weldable materials is given in the job knowledge series. The main source of this problem is sulphur but phosphorus, lead, bismuth and boron also contribute. Your base material is a steel that is prone to residual stress and rapid cooling. Use argon shielding for steel, stainless, and aluminum. Welding tips and tricks view topic dull looking welds. It can be caused by the use of the incorrect welding process or wrong welding technique. Welding tips and tricks view topic aluminum weld cracking.

Basic tips for understanding and preventing common types of. Aluminum filler 4043 or 5356 miller welding discussion forums. Something that might be an easy weld for a mig could be a struggle for a tig welder. Of the three, cracks are by far the most detrimental. Weld cracking that occurs during or shortly after the fabrication of the weldment can be classified as hot cracking or cold cracking. How to spot a good weld vs bad weld valley box of san diego.

Tig welding gtaw or gas tungsten is an arc welding process that operates at high temperatures over 6,000 degrees fahrenheit to melt and heat metals. Dec 04, 2018 weld cracking refers to a depression left at the termination of a weld where the weld pool is left unfilled. These welds are best able to meet strict radiographic requirements for high pressure, high temperature or low temperature piping. Tig welding is a manual welding process that requires the welder to use two hands to weld. Mig and a spool gun might be the way to go, you can get some good looking and strong welds. See more ideas about welding and fabrication, welding projects and welding art. This machine can handle a 60% duty cycle, which is one of the highest cycles we have on this list. This figure shows the effects of four different alloy additions on the crack sensitivity of aluminum. In the process, there can be deviations in the shape and size of the metal structure. Hugh is a cracking bloke and looking at those results has helped you out hugely.

Learn how to do exceptional quality tig welds and fabrications kindle edition by mcdonald, shawn. Tig welding takes all the fundamentals of shielded electrical welding and breaks it down into its primary forms shielding gas, electrical arc, and filler metal. Lower the amperage and move quickly to keep the weld puddle narrow. Regardless of what you do the bad part of the original weld needs to be ground out to get good results. Best practices for welding aluminum the fabricator. While using a tig welder is the best option for welding steel to copper, that doesnt mean that its an easy process, because of the properties of a steel to copper weld and the technicality of running a tig welder, performing a steel to copper weld can be a complex operation. In a bestcase scenario, a welding operator must remove the weld crack by carbon arc. The distortion forces inherent with stainless applied to a weld joint with reduced cross sectional thickness that is produced by an autogenous fillet can be a cause of cracking. I have also tried a 220 filler rod made by crown alloy, which is a maintenence type filler rod with little success. Aug 18, 2014 a good looking weld is clean and is the same color as the base metal, both inside and out. Firstly ran some beads bottom right is hughs example, the we did a couple of butt welds no pics and then a few fillets. Our employees respond to inquiries to the best of their ability based on information provided to. Mig welding stainless steel, tig welding weld reality. I am trying to weld a stainless steel fitting to 58 stainless barstock that has been gundrilled 38 inside.