Most of the time, while either walking down the road or even in your office building, you will find workers using a certain technique to weld metals together. They use fire at a tremendous temperature and some other equipment to weld metals together. However, have you ever wondered how it would feel if you were given the same task? One of the most common metal that is normally welded is stainless steel. Here are some tips for custom stainless steel welding brought to you by Fincon Installations.
- There are some welds that need the use of a high purity argon purge. One of the best examples of this is sanitary tubing used for food service applications. However, there are some stainless welds that can be adequately protected on the back with the help of copper or aluminum backing.
- You need to use a dedicated wire brush that is made of stainless steel. It should be the one that is strictly used on stainless only and it should also be cleaned thoroughly.
- Whenever there is discoloration, it basically means oxidation. Slight oxidation is indicated by the straw thru purple and blue, whereas, severe oxidation is indicated by black and grey. One of the best ways to limit discoloration is to use a gas lens cup together with chill bars is it is possible.
- It is important for you to remember that stainless steel happens to be less thermally conductive as compared to carbon steel ad it also needs approximately 2/3rd of the amperage in some specific cases. When it comes to the outside corner welds, it is best to use 100 amps for 0.125 inches thick 304 stainless steel. However, if a part of it is carbon steel than it is good to use 125 amps.
- It is best to use a size smaller filler wire in case of stainless steel welding. This is because if the filler is too large it will require more amperage in order to flow smoothly.
- Always clean the part before you start welding. At times, even an acetone wipe will be sufficient. However, the metal has to be free from any type of shop dust, tape residue, or any other similar type of coating before you start the welding process.
Reasons to Use Chill Blocks
It is important for you to know that 300 series of stainless steel is easily susceptible to a specific phenomenon that is known as carbide precipitation. This is basically a result of the combination of carbon and chromium. This creates various chromium depleted areas. This can also cause stress corrosion cracking. This is why any procedure that involves stainless steel welding should get limited time for the metal to stay at an elevated temperature.
Chill blocks are rather useful in increasing the cooling rate and thus, limits the time the metal remains at a high temperature. It is also true that chill blocks help a lot with discoloration. If you use chill blocks with a large sized gas lens, it can help limit discoloration, distortion, and the time the metal remains at a high temperature.