MEMBER ITEMS FOR SALE
Custom Knives | Other Knives | General Items
-------------------------------------------
New Posts | New PhotosAll Photos



Go Back   The Knife Network Forums : Knife Making Discussions > Custom Knife Discussion Boards > Knife Making Discussions > Heat Treating and Metallurgy

Heat Treating and Metallurgy Discussion of heat treatment and metallurgy in knife making.

Reply
 
Thread Tools Display Modes
  #1  
Old 11-15-2017, 08:15 PM
blitt214 blitt214 is offline
Member
 
Join Date: Sep 2013
Posts: 19
Temper question

Ok weird question what will affect the temper more temperature or number of cycles
Reply With Quote
  #2  
Old 11-15-2017, 10:29 PM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,514
Temperature is the main factor. Total length of temper time also figures into it. Two hours of tempering time will get you just about all the tempering effects at a given temperature that you're going to get. Some of our hypoeutictic and eutectic steels can get by with one tempering cycle. Your hypereutictic steels may need multiple cycles to get retained austenite to convert. Of course the best thing to do with these steels is not to overheat them and put too much carbon into solution in the first place.

Doug


__________________
If you're not making mistakes then you're not trying hard enough
Reply With Quote
  #3  
Old 11-16-2017, 05:45 AM
blitt214 blitt214 is offline
Member
 
Join Date: Sep 2013
Posts: 19
I'm using 1080 so more than two cycles at the same temp won't soften it any more than just the two cycles?
Reply With Quote
  #4  
Old 11-16-2017, 11:21 AM
samuraistuart samuraistuart is offline
Steel Addict
 
Join Date: Dec 2012
Location: San Antonio Texas
Posts: 161
Not really. It would take hours upon hours upon hours (a day or more???) to significantly drop HRC. The higher the alloy, the more temper cycles. No more than 3 cycles, 2 hours each.

Doug is right, most of the low alloy steels (like 1080) only need a single 2 hour temper. I've even been told ONE hour for simple steels is plenty. The Japanese would only "temper" for a very very short amount of time (not saying that it is right, but they've made millions of very nice kitchen knives using a very short primitive temper method).

For steels like 1080, 1084, 1095, I do two cycles, 2 hours each, just for peace of mind. 52100, O1, O7, CFV steels like that, I treat them as if they were higher alloy stainless and tool steels, and actually do 2 hours each cycle, 3 times. I am certain that is overkill, but it doesn't drop the HRC any.
Reply With Quote
  #5  
Old 11-16-2017, 02:15 PM
blitt214 blitt214 is offline
Member
 
Join Date: Sep 2013
Posts: 19
I did 2 one hour cycles at 400 degrees when I broke the blade it seemed like it might have still be too hard I'm not really sure how to test at what point a blade should snap
Reply With Quote
  #6  
Old 11-16-2017, 04:10 PM
jimmontg jimmontg is offline
Guru
 
Join Date: Jan 2016
Location: Now live in Las Cruces NM.
Posts: 1,077
Blitt at 400 degrees a 2 hour temper would have worked better than heating and cooling it twice. Try it at 400 for two 2 hour tempers. It should be around RC 60 if the austenize heat was in the range to leave the fine grain you said you had. The 5 degree break on .090 thick material is a bit too hard, but how hard do you want it to be? 1080 is a simple steel and if you want flexibility you'll have to temper down properly. As stuart said above you won't hurt it to temper it at the same heat, but one hour tempers are not going to temper it properly. Stuart can explain it better than I.

I temper 1080 at 425 for one temper @ 2 hours, but I haven't used it by itself for a long time except for making Damascus which I prefer to make a little softer like in the RC 57-8 range. I also made two huge daggers and tempered them at 475 because I wanted them to be more flexible as they are for a bear attack or for fighting and breaking isn't an option, but that also means they won't hold an edge as well.
Reply With Quote
  #7  
Old 05-31-2018, 09:17 AM
WBE WBE is offline
Skilled
 
Join Date: Feb 2009
Posts: 479
Flexibility is 90% more dependent on thickness than temper.
Reply With Quote
  #8  
Old 05-31-2018, 11:13 AM
samuraistuart samuraistuart is offline
Steel Addict
 
Join Date: Dec 2012
Location: San Antonio Texas
Posts: 161
Flexibility is 100% dependent on geometry/thickness than how hard it is. How hard it is will determine the failure. Bend vs break
Reply With Quote
  #9  
Old 05-31-2018, 02:48 PM
WBE WBE is offline
Skilled
 
Join Date: Feb 2009
Posts: 479
I was not sure if it was 100%, but I knew it was close to it.
Reply With Quote
  #10  
Old 05-31-2018, 02:54 PM
WBE WBE is offline
Skilled
 
Join Date: Feb 2009
Posts: 479
Hey Stuart, what happened to hypefree blades forum? My puter has down for a while, when I tried today, it would not come up.
Reply With Quote
  #11  
Old 06-01-2018, 12:13 AM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,514
I just googled it up and found redirect hype free blades. It seems that it has been having software problems for awhile and Kevin, with his other obligations and being sole moderator, decided to go in other directions and shut down the board. I don't know if he has other plans for the home site but I think that the board is gone.

Doug


__________________
If you're not making mistakes then you're not trying hard enough
Reply With Quote
  #12  
Old 06-01-2018, 07:08 AM
WBE WBE is offline
Skilled
 
Join Date: Feb 2009
Posts: 479
Thanks Doug
Reply With Quote
  #13  
Old 06-01-2018, 11:55 AM
samuraistuart samuraistuart is offline
Steel Addict
 
Join Date: Dec 2012
Location: San Antonio Texas
Posts: 161
Yeah, thanks Doug. I hope we see it return, but not holding my breath.
Reply With Quote
  #14  
Old 06-01-2018, 12:30 PM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,514
Let's face it it was pretty inactive. Though in a way that might have been a good thing because it cut down on the non-metallurgy topics. It will, however, be missed.

Doug


__________________
If you're not making mistakes then you're not trying hard enough
Reply With Quote
Reply

Tags
1084, 1095, 52100, bee, blade, carbon, damascus, degrees, edge, how to, japanese, kitchen, kitchen knives, knife, knives, made, material, primitive, question, simple, stainless, steel, temper, thickness, tool


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Temper question JawJacker The Newbies Arena 12 06-04-2013 05:36 AM
Temper after Heat Treat Question Aaron Banger Heat Treating and Metallurgy 5 02-20-2010 10:38 PM
Do I need to temper? huntforlife The Newbies Arena 10 04-12-2009 04:37 AM
To temper or not AlanR The Newbies Arena 12 08-31-2006 12:38 PM
Temper Question ? SKIVIE The Newbies Arena 4 04-25-2004 05:15 PM


All times are GMT -5. The time now is 07:25 PM.




KNIFENETWORK.COM
Copyright © 2000
? CKK Industries, Inc. ? All Rights Reserved
Powered by ...

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
The Knife Network : All Rights Reserved