I have a potential customer asking for a wedge to made for his firewood processor out of AR400. I’ve never worked with it before. Can it be cut with a torch? Do I have to keep cooling it with water when grinding? What is best to grind with?

You can cut it with a torch or a plasma cutter. You can grind it with a regular hard rock stone or a flapper wheel. I think it would be possible to overheat it with a grinder, but not letting it get too hot and letting it cool off in the air would be best. If you shock it with water it might get brittle. I have never actually tried it to see if it gets brittle, that's more of a general practice. I have also drilled it with a high quality drill bit.

I have seen a few shooting targets cut out of ar400 using a plasma cam and its welded all the time for heavy equipment stuff like buckets. Preheating wont hurt.

jody

Awesome. Thank you guys. In some older research I had seen where some people mentioned 400*F was the magic number you didn’t want to go above without annealing it. Would I need a way to control the cool down rate after it’s welded or is air cooling acceptable? Easy way to describe it would be one piece vertical and 3 wedge pieces off of either side. Each wedge will need 2-3 complete passes around it. Thank you guys again for your time!

air cooling should be fine.

Lincoln site has some pointers.

https://www.lincolnelectric.com/en-sg/support/welding-solutions/Pages/ar400-plate-detail.aspx#:~:text=AR400%20is%20a%20quench%20and,(HAZ)%20with%20high%20hardness.&text=Peen%20the%20weld%20beads%20to%20minimize%20residual%20weld%20stresses