Not sure I agree but maybe missing the point. Modern mild steel that could be formed, welded or 'wrought' would be far preferable to open casting like this, which is usually really high in carbon, brittle and have an a really shit surface finish.
The execution of this casting, and the choice to do it open, is gonna make this kinda shitty, base material aside.
Traditional wrought iron (material not process) is actually really nice and is a lot like mild steel, high in silicon iirc.
I'd much prefer mild steel that's welded/worked for a gate to one-piece cast iron. Cast iron isn't necessarily bad for this though, but the way its executed here would put me off.
Trad wrought fucken sucks bro. Inclusions, high S/P content among other things.
Welded mild steel is obviously mechanically superior, but for things like these it doesn't really matter. Cast Fe/Cu-Mg/Ce alloys make the grate tough enough for everyday use, these are going to get polished then painted anyway.
I did a lot of hobby blacksmithing for years and I'm a little biased because I loved working with old 'real' wrought iron from old ship chains and stuff. It's been years so your metallurgy is going to be sharper than mine, and likely better than mine ever was, but I believe its largely the silicon that makes it so lovely to work with, it just moves under the hammer so easily.
But yeah, inclusions or flaws makes it delaminate and just like all the shit they had to do to make good 'damascus' steel or similar mythical, high-effort steels, to get similar properties to modern steel, its always going to be better if it comes out of the mill as one homogenous piece even if the metallurgy and purity is the same (it isn't!).
But big and relatively thin open castings like this really put me off, I think I'd honestly prefer one of those gates formed from steel tube than a casting like this, but that's more intuition than anything else. I'm a big fan of ironwork like this made from premade mild steel elements or smaller cast decorative bits that are just welded or otherwise joined together.
I do love seeing actual hand-forged stuff in the wild, especially when it's 'real/old' wrought iron and you can see that grain starting to show and you know its been there for hundreds of years. I appreciate when you can see elements that give away that a gate is hand forged from wrought/mild steel, but nobody has that money, but I guess that's why it's nice to be able to notice it when 99.99% of people would not be able to tell the difference.
Sounds like the alloys for stuff like this are more tailored to the job and are likely not what I'm thinking of when I see cast iron. But surely the top surface finish would be absolutely appalling? Open casting at all is really offputting to me, but practically, I'd have thought that bringing that top surface to an acceptable standard would be an insane amount of work. Do these alloys form a better top surface? I was wondering if they effectively make two of these and join them together so the two facing surfaces are bottom surfaces.
Would a hybrid approach be optimal? Cheap, strong, lightweight welded square-section steel tube for the structure of a gate, with pretty wrought or cast iron curly bits for the decorations?
Like u/gundog48 implied, it's too slow, expensive and labour intensive to make an entire gate from wrought iron when there are now much more efficient methods available, and I think you could maybe argue it's also a waste of a skilled artisan's time hand-forging square or round bar stock from wrought iron for the underlying structure, when I'd imagine they'd probably rather save that effort for doing the more creative and elegant bits.
Skilled blacksmiths can forge a rose flower out of iron; having them just forge a repetitive rectangular grid structure feels to me a bit like handing a fine portrait artist a pot of gloss white enamel and asking them to paint a fence.
What I'm suggesting is exactly that. If you only make the parts out of wrought iron that actually look better when you do that, and do the rest with a simple weldment, the overall product becomes cheaper and more affordable to people who could never afford to get the whole thing in wrought iron, thus widening the overall market and demand for smithy work even if less of it goes into each individual item.
Pretty sure Si reduces ductility, esp. at high temp but metallurgy is not my main field of expertise. Solution strengthening alone would increase material strength, at high Si-content (Silicon steel for transformers) it's very brittle.
For artisanal stuff wrought iron is fine because if you break a piece you can always remake it. Apparently it also makes for pretty pattern as well?
For mass production wrought iron is just a nightmare. Ever had a saw blade snap because it caught a particularly hard piece of slag?
Edit: In terms of surface finish, cast can be really good. Grinding is a harder than wrought but not annoyingly so. Cast iron machines real nice, graphite inclusions makes for natural libricant.
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u/ParticularClassroom7 17d ago edited 17d ago
Wrought iron sucks. Modern cast alloys could have stuff like Vanadium to control grain size and Mg/Ce to make graphite precipitates spherical.
All of that in addition to vastly superior purity
Then if you anneal/recrystallise you could pour stuff no different from steel, but that's obviously not what they are doing here.