Spring heat treating screw up

[sydney]

Hi --I messed up heat treating a spring
       Using Dixie mat l--1075 ??
       I over heated the spring then quenched in oil
       Used the oil burning to temper
       Should I anneal before trying again??
        Sydney   

[Bob Roller]

Hi --I messed up heat treating a spring
       Using Dixie mat l--1075 ??
       I over heated the spring then quenched in oil
       Used the oil burning to temper
       Should I anneal before trying again??
        Sydney

Can you cut it with a good file.? It may be OK and if not,
it's a part of learning.

Bob Roller

[rich pierce]

Not clear what went wrong.

[sydney]

Hi---It ended up too soft--
       Not sure why ??
      Sydney

[Elnathan]

I'm sure it wouldn't hurt to at least normalize it before re-hardening and trying the tempering process again. That will get the grain size back to where you want it.

I had a knife that wouldn't harden in the quenchant I was using even with several tries, and when I switched to brine instead of oil I managed to break it while trying to correct a warp. The break allowed me to see that the grain was coarse and irregular, which I think was a result of attempting the heat treating process several times without normalizing between attempts.

It is unclear what went wrong with your spring, though. If you overheated it during the hardening process the grain size would be coarsened but it should still harden, I think. If it didn't harden properly you might need to change to a faster quenchant, like salt water. If it hardened properly but you overheated during the tempering process, than you need to alter the tempering process, though since I've never tried a spring I can't help you there.

[Mark Elliott]

I normally heat to a salmon color and then quench in quenching oil (lighter than motor oil) that I get from Brownells.    It should be hard to a file.   You should test it at this point.   I temper a spring to 700F in a heat treat oven.   If you don't have a heat treat oven,  I suggest a lead pot.   Check the temperature of the lead with an appropriate thermometer.   If you don't have a thermometer,  heat the lead until it is all just melted, and then put the spring in for 15 minutes.   That used to work for me before I had an oven.

[jerrywh]

 I suggest following Mark's advise.  But anneal it first. don't need a real long cooling cycle. Normalizing is OK.

[LRB]

  Heat to a bright orange, let cool to room temp. reheat to a good red, let cool again to room temp. Repeat a third time to just at non-magnetic, let cool. This process will give you a fine grain again. Then heat to a bright red/red-orange, quench in canola oil heated at 125° to 130°. Then check with file. It should not cut , but you may find it cuts the very surface a little because the surface may be de-carbed a few thousandths from the previous heats. As Elnathan said, brine can also be your quench, but do not use just plain water. You can make brine with a ratio 0f 13oz salt to a gallon of water.  Then temper.

[sydney]

Hi Thanks for the help
    Sydney