Thread: Heat damage?

Originally Posted by Bruno

Excuse me, but this is the workshop forum, not the good news feel good show. You have made a mistake, as we all did sometime. You learn from it and move on. This is not salvageable. No point in sugarcoating it.

The temper of that razor is shot. Kaput. That is heat damage. And a lot of it. The color progression white ->blue->purple -> bronze ->straw is an unambiguous telltale sign of a piece of steel that has gotten way past tempering. Where it is straw to bronze, the temper will still be ok. purple to blue is still good enough for a pocketknife. And near the edge where it has turned white again, the hardness will be gone.

We're not talking about a razor that has a spec of blue due to a buffing mistake. That blade has gotten hot enough to be used as a brand, along its entire length. The color is on the surface, but the temper will be ruined throughout the entire blade. And it won't be brittle. Quite the opposite in fact. But the edge is nowhere near 60 HRc anymore.

So if you fix up this razor and hone it, please don't sell it here (or anywhere else for that matter) ever, without explaining clearly that the temper was blown. Because otherwise the next person will buy this blade expecting a properly heat treated razor, but getting something that is functionally just a pocket knife.

Btw, you can still see sever rust scarring, but not a trace of rust anymore. I'd be willing to bet dollars to pennies that the blade has been pressed to a buffer by someone who doesn't have a clue.

Could the blade be reheated to a degree of cherry red and then be cooled rapidly and then retempered with reasonable expectations of restoring the steel to a useable condition?
If so, would it be benificial to hold it at this temp for awhile before hardening and tempering?
Would repeated hardening tempering cycles harm the metal other than maybe warping or cracking?

I read that it would not work because the metal is too thin at the edge? Again I am new and only repeating what I read. No real experience.

Yes and no.

If it was a big wedge, you could easily anneal it and re-heat treat, temper, and grind it. You'd lose material because the edge would have decarburized, but there would be enough material to start with.

Smaller razors and hollow ground razors, it would be very difficult.
Firstly, you'd lose enough carbon in the edge part to make it unusable.
Now, suppose you'd protect the blade with a thin clay coating or heat treating paint or something else, the quench is still very likely to turn your blade into something that vaguely resembles a ribbed potato chip. or a banana.

Your blade is in the middle. It looks like it is half hollow so it could go either way. It looks a bit thin around the edge but with protection it might just work. Or not.

That said, it would be interesting to try. After all, the razor is ruined already, and it looks like it has some material to it. If you'd care to give it a try, un-pin the razor and mail it to me and I'll do it for free, just for curiosity's sake.

Originally Posted by pixelfixed

Not sure you could get a blade that hot with a buffer,looks like it was held over a flame

Oh yeah, those thin edges will discolor faster than a bare finger can detect the heat bloom, especially for a normal buffer running at 3400 rpm. Someone using gloves "to be safe" would never feel it until it was long past too late.

Originally Posted by Galaxy51

Could the blade be reheated ...

Yes, if the heat treater new his stuff and had the right equipment. The primary problem will not be cracking but more than likely with that edge already ground to a shaving edge, the edge will potato chip (a sine wave type of warp). Even with the right equipment, it would contain an element of gambling.

Originally Posted by Bruno

Yes and no.

If it was a big wedge, you could easily anneal it and re-heat treat, temper, and grind it. You'd lose material because the edge would have decarburized, but there would be enough material to start with.

Smaller razors and hollow ground razors, it would be very difficult.
Firstly, you'd lose enough carbon in the edge part to make it unusable.
Now, suppose you'd protect the blade with a thin clay coating or heat treating paint or something else, the quench is still very likely to turn your blade into something that vaguely resembles a ribbed potato chip. or a banana.

Your blade is in the middle. It looks like it is half hollow so it could go either way. It looks a bit thin around the edge but with protection it might just work. Or not.

That said, it would be interesting to try. After all, the razor is ruined already, and it looks like it has some material to it. If you'd care to give it a try, un-pin the razor and mail it to me and I'll do it for free, just for curiosity's sake.

I am honored at such a gracious offer. I will gladly send you the blade to see if you can fix it! Please let me know where to mail it! Maybe it will help other board members as well. Razor is unpinned already. Thanks!

Blade is coming your way! On a side note I opened a case against the seller on eBay. I don't expect to win but maybe it will make his life hell for a while.

Originally Posted by pixelfixed

?????????????????

I have seen color change on a blade when rinsed with really hot water. Not that kind of discoloration as the OP, razor, but definitely visible.
I have also seen a blade with that kind of discoloration, hollow ground, that had not temper issues.
The thing to do before pronouncing the blade dead based on a pic is to hone it and see if the take edge first.

the exact same colors can result from exposure to an acid. done it many times with a carbon steel knife cutting lemons.

I have never seen a blade turn colors like that from cutting lemons nor from rinsing in the hottest water.If you have seen it many times. lets see some pics.
That Blade is kaput, with the amt of pitting and hone ware, it should be laid to rest.Sometimes the newbs should be told the truth,you bought junk,you got junk.Ask a mentor about a blade you have an interest in via P.M, before buying or bidding,thats what mentors are here for.
Some of the junk newbs buy and post pics of is at times unreal,JMO, sorry for the rant.