Lerch
Well-Known Member
Hi all
I searched a bit for this answer but could not find it, so if this is a repeat of a previous question i apologize.
I am currently working with 440C and will also do some CPM154. The blades i have done so far were all 440c and this has been my process.
Steel foil wrap the blade with a small piece of wood for oxygen take up. initial heat treat is 1900deg for 15min. I plate quench until i can pick the blade up bare handed. I place a fan in front of the open oven door to speed cooling and once the oven is at 375deg i place the blades back in for a 2hr tempering at 375deg. After the 2hr tempering the oven shuts itself off and begins slowly cooling down. What i have been doing is leaving the blades in the oven while it cools down until i reaches around 100deg, this takes around 2hrs or a little more.
after this i take the blades and place them in between two blocks of dry ice in a yeti cooler for around 12-24hrs. i use the yeti cooler because it locks up so tight the ice will last for about 2days as opposed to about 10hrs if i put them in my refrigerator freezer.
after this i let the blades warm to room temp and place them back in the evenheat oven for two more 2hr temper cycles and the same cooling in the oven process as before.
is this good or what would be better?? once the 2hr cycle is over should i remove the blades to let them cool more quickly in open air? should i lay them on my aluminum blocks to cool a little more quickly?
thanks
steve
I searched a bit for this answer but could not find it, so if this is a repeat of a previous question i apologize.
I am currently working with 440C and will also do some CPM154. The blades i have done so far were all 440c and this has been my process.
Steel foil wrap the blade with a small piece of wood for oxygen take up. initial heat treat is 1900deg for 15min. I plate quench until i can pick the blade up bare handed. I place a fan in front of the open oven door to speed cooling and once the oven is at 375deg i place the blades back in for a 2hr tempering at 375deg. After the 2hr tempering the oven shuts itself off and begins slowly cooling down. What i have been doing is leaving the blades in the oven while it cools down until i reaches around 100deg, this takes around 2hrs or a little more.
after this i take the blades and place them in between two blocks of dry ice in a yeti cooler for around 12-24hrs. i use the yeti cooler because it locks up so tight the ice will last for about 2days as opposed to about 10hrs if i put them in my refrigerator freezer.
after this i let the blades warm to room temp and place them back in the evenheat oven for two more 2hr temper cycles and the same cooling in the oven process as before.
is this good or what would be better?? once the 2hr cycle is over should i remove the blades to let them cool more quickly in open air? should i lay them on my aluminum blocks to cool a little more quickly?
thanks
steve