Читать книгу Welding For Dummies - Steven Robert Farnsworth - Страница 47

You can do a whole lot of welding with only steel, stainless steel, and aluminum, but you’ll inevitably want to branch out a little and work on some less commonly welded metals. Here’s a quick rundown of some of those metals, and you can find more information on them sprinkled throughout the other chapters of the book.

 Copper and copper-based alloysUsed for: Plumbing, electrical products, roofing, and as an additive to gold and silver to increase the strength of jewelry.Welding process: You can use mig or tig welding for copper and copper-based alloys. Mig welding works in all positions and it’s especially useful for thicker pieces of copper. If you use mig for welding copper, be sure you use direct current electrode positive (DC+). Go with tig if you want to weld thinner pieces of copper — I recommend using direct current electrode negative (DC–).

 MagnesiumUsed for: An alloy in steel. Makes steel resistant to abrasion, so it’s perfect for rock crushers, grinding tools, grinding mills, and so on.Welding process: Use tig for welding thin pieces of magnesium-based alloys; use mig if the pieces are thicker. Some magnesium-based alloys have high levels of zinc in them. Avoid welding those alloys if at all possible because it’s extremely hard to keep them from cracking.

 Nickel-based alloysUsed for: An alloy in stainless steel. Nickel in the 200 and 300 series stainless steels is the most resistant to corrosion.Welding process: You can use any of the big three arc welding methods for welding nickel-based alloys. Stick welding gives you a weld that’s stronger than the base metal. (That’s good!) Tig welding a nickel-based alloy involves using a 2 percent thoriated tungsten electrode and argon as your shielding gas. You can tig weld a nickel-based alloy in any position. (If some of those terms look a little wacky to you, flip over to Chapter 7 for some gory tig welding details.) Finally, if you’re going to be mig welding a nickel-based alloy, plan to use a 50/50 mix of argon and helium for your shielding gas. Like tig, you can mig weld these alloys in any position.