HOW TO WELD 4140 by Rod Ryker
PREHEAT, IF YOU DESIRE, 'TILL YOU SEE DARK BLUE ALL AROUND THE DESIRED WELD AREA. OR IF THE MATERIAL IS 1/8 INCH THICK OR LESS, NO PREHEAT NEEDED.
USE AN ER80S DOUBLE DEOXIDIZING, OR ER70S2 FILLER, WIRE.
ARGON GAS OR ARGON/HELIUM MIX FOR THICKER SECTIONS. GAS FLOW SHOULD *NOT BE FAST* AS THIS IS CAN CAUSE CRACKING. A GAS LENS AND A LARGE CUP IS *HIGHLY RECOMMENDED*.
4140 LOVES HEAT!
SO, WELD VERY SLOWLY, PRODUCTION SPEED'S ARE *NOT RECOMMENDED*!!!
Well now I shall explain in detail.
4140 can crack instantaneously after the bead is run.
Too much gas causing a cooling effect or too little gas causing air to be drawn in the weld area - contamination.
Not enough wire in the weld, or the wrong type.
Welding speed is too fast!
1. We must cover welded 4140 material immediately after welding to retain the heat so it won't crack.
Because, any cracking will happen because of the poor welding procedures as I've discussed above.
2. We must immediately, after welding, place the material on a truck and send it to the - waiting heat treat centre - so it won't crack.
Why not INDEED! Just put a big fan on it in a freezer setting. What difference would it make? (Rhetorical) You would be defeating your own misguided thinking.
If the part is welded as I say and after heat treat you have cracking, then the rules of temperature WERE NOT FOLLOWED DURING HEAT TREAT FOR THE MATERIAL!
KEEP IN MIND THIS MAY BE YOUR FAULT! YOU MUST TELL HEAT TREAT THE TYPE OF WELDED MATERIAL THAT YOU WANT TREATED!!! SUCH AS PRE-TREATED, OR NOT.
Rod Ryker... It is reasoning and faith that bind truth.