HT stress releiving of 1084

[swamp]

Hi guys, I have a quick question. I just did my first sucessful HT on a 1084 blade that did not shatter like glass. Question is: I have it in the oven right now at 400 degrees for 90 minutes. Is that too long or hot? I plan to do this three times. Thanks guys.

 

[RyanW]

Nope that sounds right... Most (Myself included) are doing two tempers for 1 hr. each, but you can do 3. Biggest concern is how good your oven is, if it loses heat fast you need to make sure you have it in some type of heat barrier. I use a Cookie Pan covered with Foil so that the blades aren't overheated each time the oven tries to bring the temp back up to 400 Degrees.

 

[swamp]

Thanks Ryan, I learn stuff all the time on here. This is really exciting.

 

[Daniel Fairly Knives]

That sounds good. I usually go for 150 minutes but that is overkill and I always do at least 2 tempers. In my opinion two cycles must be done with most steels.

 

[swamp]

Does three do any better than two? Or am I wasting time?

 

[SBuzek]

Does three do any better than two? Or am I wasting time?

On 1084,probably wasting time.
Stan

 

[LRB]

I give this a shot. IMHO, your not hurting anything, but 2 + 2 should get it done for most steels. In the first temper heat, you are tempering the martensite you created from austenite when you quenched. There is always some austenite that does not convert in the quench, but does in the temper cool down, creating new martensite that needs to be tempered. The second temper process will take care of most of that. A third temper will get more yet, but not enough for any significant measure. It does work out as a waste of time, but does no harm if you really want to do a third temper.

 

[Daniel Fairly Knives]

I give this a shot. IMHO, your not hurting anything, but 2 + 2 should get it done for most steels. In the first temper heat, you are tempering the martensite you created from austenite when you quenched. There is always some austenite that does not convert in the quench, but does in the temper cool down, creating new martensite that needs to be tempered. The second temper process will take care of most of that. A third temper will get more yet, but not enough for any significant measure. It does work out as a waste of time, but does no harm if you really want to do a third temper.

Exactly!