Steel cracking

[garbear]

I'm attempting to make a flint striker.  I'm using coil spring from garage door.  My issue with the second n third is cracking in the steel while I'm forging.  It isn't happening at the quench stage.  I set them aside didn't go that far once I seen the cracks.  Mostly I'm thinking I need to normalize but couldn't find answer searching.  Thanks for the help.  Oh I'm sure it's plenty hot because it's orange nearly yellow when it gets to my anvil.  The shape simple d shape. I'm squaring the round after straightening.  Hope I gave enough info. 

 

Garbear 

[bigfootnampa]

The two most likely problems I can think of are: continuing to hammer after the metal is too cool or burning the steel.  A picture or two might help us to help you.

[jmccustomknives]

I've used some of those springs, they aren't exactly the best steels.  My thought is you are either working it to hot or to cold.  Get a magnet and test it as you heat it, when the magnet stops sticking that is the lower forging heat.  Don't let it spark, that's too hot.

The spring I have I'd guess was no more that 1045 carbon steel.

[JHCC]

Burning the steel is more than just a surface effect; the damage can go quite deep. Here's a piece of 5160 (I think) that overheated when I wasn't paying attention:

[ThomasPowers]

Overheating is as bad or worse than under heating.  You may want to experiment and find what temperature THAT PARTICULAR ALLOY wants, and remember the next spring might be different!   If it was replaced due to failure it may have fatigue issues and best be used as scrap...

[Steve Sells]

Some alloys have a welding temperature that  is so much higher than the forging temperature that there is a large range between the two where no forging is recommended

.  Trying to work steel outside the recommended range for that alloy is asking for troubles.

 Also a few alloys do not react well to what most smiths think of as a normalizing cycle. and others need a preheat and resting at that lower temp to equalize before getting to the forging temperatures.   Discovering these temperatures is one of the joys of using found metals

[garbear]

The steel isn't sparking coming out of the forge. I'll try get pictures tonight at dusk.  I he st section of spring unwind section n hot cut. I heat and straighten and start squaring. One heat for bending one end another heat to bend second end. Can scale cause cracking?   Got thinking might be issue but not a lot of scale when it comes out.  

The color is a bright orange almost a yellow color. I'm using small propane forge. I stop hammering when Cole does to deep dark red.  Mostly whether steel will work fir striker or not also for practice 

Thanks Garber 

[VaughnT]

Generally speaking, garage door springs make good flint strikers.  However, you never really know what the alloy is and how it will take to being forged.

It sounds to me like you're possibly working the steel too much, not overheating the metal as much as heating it back up too often.  Some alloys don't like being forged except in a very narrow range of temperature, and anything outside that zone causes issues.  It might be 'bright orange' but that color you're seeing is several hundred degrees on the wrong side of the forging temperature for that alloy.

Also, if the metal is scaling up on you and you drive that scale into the surface of the steel when you're hammering, you can get what looks like cracks but really isn't.  It's just texturing caused by the scale.

Overall, hard to say exactly what's going on.  I've had some mystery metal really give me fits for no apparent reason.  Could be cheap chinese steel.  Could be something else entirely.