Wow heat treat issue 1084

J

Johnnymichigan

Joined
Feb 26, 2019
Messages
128
Hey guys I'm a maker only for about 5 months. My first heat treat was in a dear friend and experienced makers shop until I got a kiln. I did my first 1084 heat treat w my even heat kiln and at the advice of others more experienced than I I quenched in water instead of canola. I will be receiving my professional grade quench oil in the mail soon so I know of the importance of that. He told me I may crack the blades but it's better than canola. The water quench seemed to work and I was super excited until I was almost done w the knife in the picture. I was sanding the perimeter or spine and noticed a scratch I couldn't sand out. After sanding and then finally grinding down the spine no luck. I figured it may be a crack. So as I ground the spine too far down and I'm not selling a knife w a possible crack I put it in the vise and broke it w a hammer. I noticed it broke right where I marked the "scratch" and it has some dark areas at the top as you can see. The grain structure seems good except the top where that dark part is. Any ideas? I quenched edge down and because I didn't understand what he meant I thought he meant quench the edge and wait a second then submerge the blade. What he really meant was quench edge down and immediately fully submerge. He was sick so only instructions through text message. So we tested them in his Rockwell tester and they were 61 Rockwell. So it seemed like a success until this. As I was grinding I saw in the steel what looked like wave patterns but I could grind them out. Only a few of them. What happened guys???
 
You can see the dark spot near the spine where is looks way different. I know I screwed up the heat treat I guess but I'd like to learn from this what happened
 
Stacy E. Apelt - Bladesmith said:
What happened is you water quenched the blade. Use a fast oil if you don't want to crack them.
Click to expand...

Hi Stacy. I'm Jon. Your advice has helped me a lot over the time I've been doing this. Thank you. What was the dark spot at the spine? Yes I don't want to do that again. I have some quench coming soon. I think McMaster 11 second oil?
 
Did you Quench all your blades in water?

Your Dear Friend did warn you that you might crack the blades using Water Quench...That's what happened.

The Dark spot is from a Stress Riser that created the crack in the Water Quench.

Canola is about as Good a Quenchant without being commercially engineered for heat treating AND Better than Water on 1084 which prefers a bit slower quench time...many makers have used Canola with great success in place of commercial quenchants.
 
Agree with the others regarding canola until you get fast oil like Parks 50. If you're not doing a normalizing/grain refinement procedure your grain won't be as fine as it could be. It's hard to tell from the pictures but the grain looks a little on the large side to my eye.
 
YEs, the dark spot was where a crack started. It is often referred to as a micro-crack. The opening may have been so small and thin you didn't see it until it was smoothed and shiny. The opening allowed some oxygen in the crack and the steel darkened during the cooling down and tempering. The shiny steel is where the crack propagated from the micro-crack downward along the grain boundaries when you broke it.
 
I just ordered Parks AAA for quenching. Sound like a good choice? I was going to get McMaster 11 second oil but was told parks would be good for 1084 and 52100 which I normally use. I also use 80crv2
 
AAA is great for most carbon steels, but is a tad slow for 1095, W2, 26C3, and similar steels. Thinner blades in those alloys will harden OK in AAA. Get the HT nailed right and you will likely be fine.
 
Got it. I ordered both. I only
Could get one gallon of each. I'm going to freeze water in a half gallon jug and freeze it to cool the oil between blades till I can afford more oil. Sound good?
 
One important thing to remember about using frozen water jugs is to wipe off all the condensation before each dunk …. or you will be putting water in your oil.
 
You must log in or register to reply here.
Back
Top