I was travelling over much of the last three weeks and did not have the time to weigh in on this discussion previously by cell phone.
In a retail store that has a product section labeled “Weldable Metals” is going to refer mostly to Low Carbon Steel with 10-20 points of carbon which generally welds well with appropriate rod, wire etc.
A Medium Carbon Steel will have 20-50 points of carbon and will likely require preheating and post heating. Anything over 20 points will.
High Carbon Steel with 50 points of carbon or over, weldable with special techniques and some provisions for stress relief. It may require OFHC (oxygen-free high thermal conductivity) as a brazing filler metal.
Cast Iron welds fair with preheating and post heating cool down otherwise the weld will be brittle and break otherwise. It’s done in specialized environments.
The following I snagged from
http://weldit.com/carbon-steels-2/ as it begins to discuss valuable info a welder needs to know. This is but a small excerpt.
IDENTIFICATION AND USES
An approximate identification of the type of carbon steel can be achieved by the use of the “file test.” A file will easily bite into low carbon and mild steel. Pressure needs to be applied to the file for it to bite into medium carbon steel. For a file to bite into high carbon steel extreme pressure needs to be applied to the file. All carbon steels are magnetic.
Low carbon steels are used for making nails, rivets, pipe and wire. Mild steels are formed into plates and bars. It is used for welded structural shapes, tanks, pipes, machine parts and machine bases. Medium carbon steel is used for applications such as axles, shafting, machine parts, tools and heavy equipment. High carbon steels are made into items such as springs, railroad rail, dies, chisels and taps.
I have some go to people that I trust on the web when I need an answer or advice in welding. I am primarily a MIG welder and a hobbyist by definition when compared to Jody Collier at
http://www.weldingtipsandtricks.com/
I like the way Jody does a no-nonsense approach to instruction by knowledge sharing from experience in his Welding Tips and Tricks videos. No matter what your need; stick, MIG, TIG, Aluminum, etc. he has articles, free videos, and a host of other things. You may find signing up for his free weekly video email a really good way to gain knowledge. He does have an online store, a YouTube Channel, a Forum, and is on Facebook.
In addition to the file test I cited above, you can use a portable or grinder / spark test to visually roughly indicate the metal carbon content. Here is a chart from a post in Welding Tips and Tricks Forum. It is helpful info. There are a series of Spark Test YouTube videos out there as well. Chemical test will tell you the exact metal you are working with, and that can be necessary to know in specialized repairs.
I am just replying to the new term to you “Weldable Metals” and trying to give anyone who has welding questions some places to go for more info.
Everett
- Spark Test from a Welding Tips and Tricks Forum post.png (256.94 KiB) Viewed 2496 times
