Hello Eddie,

I really can't make too much out in the image as it is a little out of focus, I doubt the grains are grossly enlarged, otherwise it would have a "sparkly" appearance even with the blur, but there could still be room for further refinement, can't really tell. But if you are open to other advice I would offer this:

What do your normalizations consists of? Actual normalization involves completely resetting the internal condition of the steel by going to full solution temperature, and this need only be done once. Many bladesmiths refer to grain refinement heat cycles as normalization but by necessity they are actually lower than proper normalization temperatures, and these can be repeated for further refinement. Of course only you and your customers can determine the edge performance level desired, and how often you want to sharpen, but for me 56-58 HRC is too soft for a blade of this type and size in 1084. This appears to be more of a trailing point skinner and I, myself, would leave it at 61 or even 62, but the edge geometry would have to be appropriate, of course. The lowest I would go with 1084, even for larger 10" chopping blades would be 58 HRC, once again, with appropriate edge geometry, unless I anticipated extreme abuse.

'Kevin R. Cashen'

Thank you, for the advice. I'll work to get the hardness you recommend. I typically do a saber grind for the bevels. I thought the complete resetting of the steel was annealing. For what I referred to as normalizing I bring the blades to critical, and let cool to the touch each cycle. Does this help with the refinement of the grain structure or am I waiting time in doing it? Thank you once again for the advice. It helps me and I look forward to improving.

I have only some moderate feedback from another AP perspective. As Kevin said, it's difficult to tell a lot from a photo, but I think the grain is not uniform. It looks a little coarser along the right side of the photo. That could just be the focus of the image though. As for the other question of how often I break blades to check the grain, in general I do this several times when I start using a steel I am unfamiliar with. Even though I follow HT guidelines from guys like Kevin Cashen, Tim Hancock, or John White, I still make a few smaller blades, HT them and break them to make sure I got the HT right. I also make & break one every couple of years just to see whether I have gotten sloppy...... <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//blink.gi f' class='bbc_emoticon' alt=':blink:' />

Joshua States

Thank you for the input. I'm planning on doing it at least a couple times a year.

|quoted:

'Kevin R. Cashen'

Thank you, for the advice. I'll work to get the hardness you recommend. I typically do a saber grind for the bevels. I thought the complete resetting of the steel was annealing. For what I referred to as normalizing I bring the blades to critical, and let cool to the touch each cycle. Does this help with the refinement of the grain structure or am I waiting time in doing it? Thank you once again for the advice. It helps me and I look forward to improving.

There is often confusion between annealing and normalizing. The most distinguishing difference between them is the desired effects in the outcome. Annealing is typically done at slightly lower temperatures for the purpose of removing any strengthening or hardening effects in the metal; it may, or may not, involve recrystallization but will aim to remove carbon from solution to form various forms of carbide and definitely reset the atomic lattice into a more strain defect free condition. e.g. annealing cold worked copper has nothing to do with carbon or carbide, but it does involve reordering the stacking into a more malleable state. Annealing often involves very controlled cooling, either slower or isothermal to accomplish the separation of carbon from solution, and will thus result in a more segregated state.

The resulting hardness is almost irrelevant to normalizing, which involves the highest temperatures, outside of forging, of any of the common heat treatments. Its goal is to homogenize the internal condition of the metal. This includes recrystallization, of course, as well as full dissolution of carbides. Its rate of cooling is that of still air, period, no other cooling rates can be applied and still have it be normalizing in the traditional sense. The resulting condition is as uniform as possible rather than heavily segregated. Grain size may actually be a little larger s long as it is uniform.

Grain refinement, as size is concerned, is accomplished with follow up heating ad cooling cycles that are lower in temperature and do not require carbide dissolution, and thus can not technically be called "normalizing." In fact heavy cycling at lower temperatures while it may refine, could coarsen or segregate carbide which is essentially undoing the effects of normalizing.

Kevin R. Cashen

Thank you for the clarification. Here is what I hope are better pictures (both sides of the brake) of the grain structure inside the blade I broke.

* I'll re add the pics after I get them resized*

Much clearer. But, unfortunately, too coarse.

Kevin R. Cashen

I'll work to improve it. Thank you.

Kevin R. Cashen

I'll work to improve it. Thank you.

|quoted:

Hello Eddie,

I really can't make too much out in the image as it is a little out of focus, I doubt the grains are grossly enlarged, otherwise it would have a "sparkly" appearance even with the blur, but there could still be room for further refinement, can't really tell. But if you are open to other advice I would offer this:

What do your normalizations consists of? Actual normalization involves completely resetting the internal condition of the steel by going to full solution temperature, and this need only be done once. Many bladesmiths refer to grain refinement heat cycles as normalization but by necessity they are actually lower than proper normalization temperatures, and these can be repeated for further refinement. Of course only you and your customers can determine the edge performance level desired, and how often you want to sharpen, but for me 56-58 HRC is too soft for a blade of this type and size in 1084. This appears to be more of a trailing point skinner and I, myself, would leave it at 61 or even 62, but the edge geometry would have to be appropriate, of course. The lowest I would go with 1084, even for larger 10" chopping blades would be 58 HRC, once again, with appropriate edge geometry, unless I anticipated extreme abuse.

Hello, very good to all, and I have been reading this topic that is very interesting for me, I do not know if I misunderstand when a good hardened and a good temper is done, checking that hardness and obtained (HRC) if I split the grain that must have is it homogeneous and bright?