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Jeroen Zuiderwijk

Blister/shear steel

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Howdy

sorry my english is not so good, but it can be that you now have a very clean high to midiumcarbon Steel and this kind of steel needs Brinn to harden proberlie. give it a dry, ad some Salt und a litel dischwash and maybe it works :rolleyes:

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I do not think you are welding cast iron at a low red heat. Judging the temperature of my forge (by eye) seems to be a real problem for me. I have lost two little wootz cakes during the annealing process, one melted and oxidized the other squirted some of its inner self out of the deoxidized shell.

 

To get a better idea of forge temperature, I now routinely place a bit of cast iron on a flattened piece of low carbon or wrought iron, and hold it in the forge. This needs to be fluxed or the shape of the cast will not change even though the inner mass has melted (hey that is just like the last wootz cake). What I am finding is grey cast melts (in about 30-50 seconds) into a very low viscosity puddle, some very fine sparks seem to escape through the flux and when pulled out of the forge it appears effervescent (that is either the Silicon or Carbon being reduced). This tells me I am at 2200 F or above.

 

The last time I did this I used some low Si, low S cast iron, put it on wrought, left it in the forge for about 1 minute after melting ( this material had a higher viscosity by the way) and folded it several times. It welded just fine (high carbon face to high carbon face) and shows a pattern ( the piece is very small so I do not want to extrapolate too much ), the lines between the high and low carbon are not crisp but gradual and there seems to be a thin much darker line at the original location of the cast iron. I do not know the M.P. of this material, I only use gray cast for that.

 

Jan

 

A caution here! When welding some of this cast/wrought stuff, I noticed what I assumed to be flux traveling right through my heavy cotton pants to my skin. You may be squirting liquid cast iron around the room. This is certainly the case when you have not judged the time of austenizing and diffusion correctly.

Be careful and make sure the kids do not come walking in on your welding.

 

Jan

 

 

Jan

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thanks for the imput guys. and lihan i'll try the brine thanks

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"Parks Metallurgical #21 is what I used, which will work faster than plain charcoal carbon."

 

 

Christpher.

 

I had seen on your website that you had used Parks #21. Did you get this directly from Park, or another source. I'd like to try some. Thanks ~Herb

 

 

Again, thanks go to Ric... he buys it by the barrell, and sent me a box of it to play with. I'll probably be getting a larger supply for myself, after I come back home from California. Along with more wrought.

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And, shear is by definition welded and processed blister, so unless you're making that first, then it ought to be called something else, if we're getting technical.

 

I think I'm going to go the Louis Mills route with some of this, though, and take metal feedstock of various qualities, and feed them through a charcoal reduction, and weld that up, alongside making traditional blister/shear for the next couple years. I need to cobble together one of those catlan forges, I think, or the micro-smelter that Skip designed.

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O.k. , so i got a mix of 2 parts wrought to 1 part cast and i welded it up to just over the 1000 layer count today. A rough grind and etch revealed a superfine pattern what appeared to be layers of the wrought and layers of bright white which i am guessing is the cast. Each fold of the 9 was welded then drawn out in one heat. There was no soaking time at the end to allow for carbon migration (yet). I wanted it to be refined to the point where the cast wouldnt just melt and run out.. Before I called it a day I cut a small bit from the billet brought it to critical and quenched it to see what would happen. Nothing. I tried a few other things and got no effect. Now I personally think the reason for this may be that there was infact next to no carbon migration during any of the welds and I just have a billet of cast iron and wrought iron and not anything that you can call steel yet. Or, did I in the process of welding actually fry out so much of the carbon that I have something that its just below the hardening range of steel. Any thoughts on this? Also , if this did make steel would it even be classified as shear steel?

 

First,

Well done..this is not a simple weld.

Second,

the cast will go liquid at about 2175F so it is avery low temp and it may be dripping away with the flux to some extent.

When I did billets like this it took about six welds before it started to act like a billet and not greesed bearings on a plate...a press helps a lot. Gentle is the way to go...you are nudging rather than hitting hard.

 

The carbon will move faster once it is in contact..ie larger surface area along the drawn out weld interface. At some point a long soak does as much as more forging.

You can jusge carbon migration to an extent because the welding temps will go up as the carbon equals out.

 

As to the thing not respoding to the quench...what you have in aperfect world, is a low hardenability material with few alloys and as such the quench may need to be more severe (faster) and the uastenizing temps may need to be higher......this is not in any book I have seen, but it seems to proove out inmy shop at least.

 

Try a small end cut with a three minute soak at 1800F and a water quench and see if it gets hard at all.

 

Also what is the spark? Is it red with no bursts or what? Does it look ike a drill bit being ground?

 

Ric

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I recall having downloaded a good 19th century manual from google books with a detailed description of teh blister steel process including times and temperatures that were required.

 

It was a process that endured for days ovens were very big and many bars stacked in crates could be treated. penetration of carburized layer was significant, with teh bars sitting in the middle of crates being less affected due to lack of heat.

 

In any case it is a process that depends from a combination of time and temperature, theh higher the temp the lesser the time required to reach for a given penetration of carbon into the item.

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Very true, GBC. At traditional temps, it would take days. Sheffield did this a lot. I've seen Ric do it in 3 or 4 hours, I've done it in 6. All depends on how hot you get it.

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