- Joined
- Nov 16, 2012
- Messages
- 5,596
Oh well... Win some, lose some!
Here it is heat treated to RC62 and sand blasted... -and look what the sandblasting uncovered... a fracture. This is what I get for not following the procedure. In this case, I did not normalize the metal before machining it. Everything else was done by the book. Most likely, it had a bunch of internal stress that busted loose somewhere along the line.
The part was slowly brought-up to 1500, held for 10 minutes, oil quenched down to 150 degrees then tempered at 350 for 1 hour. The new piece is now in the furnace getting normalized... I get to do this project over. The crack is so deep, I won't even risk practicing on it in the tool grinder.
Live and learn.
(BTW: It actually tested at 62 RC so that's encouraging).
Ray
Here it is heat treated to RC62 and sand blasted... -and look what the sandblasting uncovered... a fracture. This is what I get for not following the procedure. In this case, I did not normalize the metal before machining it. Everything else was done by the book. Most likely, it had a bunch of internal stress that busted loose somewhere along the line.
The part was slowly brought-up to 1500, held for 10 minutes, oil quenched down to 150 degrees then tempered at 350 for 1 hour. The new piece is now in the furnace getting normalized... I get to do this project over. The crack is so deep, I won't even risk practicing on it in the tool grinder.
Live and learn.
(BTW: It actually tested at 62 RC so that's encouraging).
Ray