Another z wear laminate test

[HSC /// Knives]

Last Wednesday in London i met up again with Tim at clement knives to do another attempt at z wear San Mai. Ray Rybar MS had told me that z wear would stick to pure iron. I was able to locate some pure iron in the UK courtesy of Catcheside.

Tim has a rolling mill which makes things easier. Some pics of that day

I’m back home In AZ so yesterday I annealed the billets and today I will heat treat them and see what we have.

 

[TB_London]

Nice, how much carbon migration do you reckon you’ll get into the iron?

 

[HSC /// Knives]

Nice, how much carbon migration do you reckon you’ll get into the iron?

I really have no idea to be honest. It’s all R and D at this point

 

[LostHighway]

An interesting experiment if you can make the process efficient enough to reduce the costs of producing a finished Z-Wear knife. In some ways I think warkomi or san mai construction makes more sense for the the highly wear resistant steels than it does for the commonly used Japanese alloys (corrosion resistance aside) but perhaps I'm missing something.

 

[HSC /// Knives]

This is my 4th try in the last year. I’ve tried stainless, mild steel, wrought iron and now pure iron. This may be my last attempt.

 

[LostHighway]

This is my 4th try in the last year. I’ve tried stainless, mild steel, wrought iron and now pure iron. This may be my last attempt.

The iron failed to bond? The ground end in your hand seems to suggest success, at least to a non-knifemaker.

 

[HSC /// Knives]

The iron failed to bond? The ground end in your hand seems to suggest success, at least to a non-knifemaker.

It appears to have bonded with the pure iron and in an end hammer hit (destructive test) it held together and didn’t split. I’m heat treating it now.
Any other delamination is exposed after grinding
With the wrought iron it stuck together but there was some delam defects
These two pics are the wrought iron

 

[daveb]

“Le mieux est l'ennemi du bien. (The perfect is the enemy of the good.)”

To this user (who knows nothing of making) - appears Voltaire may be talking about this venture?

 

[LostHighway]

How reactive is the pure iron? I world imagine very reactive.

 

[captaincaed]

I love this exploration.

 

[Bert2368]

How reactive is the pure iron? I world imagine very reactive.

"Pure Iron", if it is what a CHEMIST would consider pure, is surprisingly resistant to corrosion. CAST IRON and WROUGHT IRON/DUCTILE IRON are the ones that turn red and black at the slightest hint of moisture in the presence of Oxygen.

Reason being, both these commonly used forms of "Iron" have plenty of Carbon particle inclusions throughout. Each little bit of Carbon forms a little "battery" in the presence of any water and Oxygen, these little batteries make pits as they run, oxidizing the Iron.

No Carbon (or other impurity inclusions) = no origin sites for galvanic corrosion.

Did you in fact find billets of chemically pure Iron?! A rare thing, outside a chemical supply house or laboratory.

 

[Bert2368]

I recall a now deceased J knife maker (Jin) who used Copper bonded (brazed?) billets of high speed steel and soft Iron- The knives were said to be quite good (the man was swimming up stream hard, he also sharpened his knives with OIL STONES). Is there any thing in that technology that makes sense for what you are after?

https://www.japaneseknifeimports.co...-02-jin-190mm-high-speed-steel-pety-with-saya

 

[LostHighway]

"Pure Iron", if it is what a CHEMIST would consider pure, is surprisingly resistant to corrosion. CAST IRON and WROUGHT IRON/DUCTILE IRON are the ones that turn red and black at the slightest hint of moisture in the presence of Oxygen.

Reason being, both these commonly used forms of "Iron" have plenty of Carbon particle inclusions throughout. Each little bit of Carbon forms a little "battery" in the presence of any water and Oxygen, these little batteries make pits as they run, oxidizing the Iron.

No Carbon (or other impurity inclusions) = no origin sites for galvanic corrosion.

https://scottrentscharleston.com/fhh/rusting-of-iron-is-an-example-of-rapid-oxidation.html
Did you in fact find billets of chemically pure Iron?! A rare thing, outside a chemical supply house or laboratory.

At least one of the surviving Ashokan Pillars (circa 400 CE) in India is said by some sources to be of pure iron and has not rusted in the subsequent 1,600 years, however, other accounts say it hasn't rusted due to the presence of about 0.5% P (Phosphorus) in the iron. In either event I should have remembered that example. South India was also making wootz steel more than 1500 years ago.

 

[Bert2368]

At least one of the surviving Ashokan Pillars (circa 400 CE) in India is said by some sources to be of pure iron and has not rusted in the subsequent 1,600 years, however, other accounts say it hasn't rusted due to the presence of about 0.5% P (Phosphorus) in the iron. In either event I should have remembered that example. South India was also making wootz steel more than 1500 years ago.

The corrosion resistance results from an even layer of crystalline iron(III) hydrogen phosphate hydrate forming on the high-phosphorus-content iron, which serves to protect it from the effects of the Delhi climate.[5]

Looks like it's more equivalent to modern Corten steel or such where the surface oxidation forms a tightly bonded layer, protecting the interior metal, rather than CP Iron. 5 tons of CP Iron would have been quite unlikely at the period this was made. I think I have derailed this thread sufficiently now...

 

[TB_London]

If you need another experiment it may be worth sticking a nickel layer in the middle, carbon barrier and may help it all stick together

 

[Ruso]

Any update? Did it held up together?

 

[HSC /// Knives]

Any update? Did it held up together?

Update yes. I procrastinated on an update because it wasn’t totally successful and so it’s discouraging

I heat treated the 2 right away. Didn’t bother to temper them for a quick grind test reveal.

the smaller one looks pretty good in terms of bonding. But there’s some crumbling of the steel towards the heel. I’ve experienced this before in the previous tests.
The big one is no good in that the steel is destroyed or burnt.

while the results might point to overheating the steel, I’m not certain that’s the case. We have been careful about this concern.

anyway my research and development budget is small so I don’t see anything happening on this for some time now.

and yes @TB_London I think a nickel layer would have been appropriate

the bottom 3 pics are all the small one