Thread: Metallurgy of old steel vs. new forged blades

Hello,

I have a question to the "metallurgists" of our board.
Sometimes it is stated, that old forged blanks are especially good (also vintages blades...).
You can read for example "this is made of over 50 year old blanks ....therefore the steel is especially fine and even...etc."

Frankly I can not understand the reason why?
Why should it not be possible with today's technologies to produce alt least the same "quality" steel or even better?

Do you have a explaination or is this a question of philosphy?

Regards
hajo

Helo Hajo.
Some years ago I saw a program on TV. It was about blacksmithing. The guy there said that you can't weld two modern pieces of metal together in the old fashion way without lot´s of chemicals. As for the iron up to around 1900-1920 it was clean enough to simply heat and hammer together.
The quality of the old iron was wide higher than today.
I also made a visit to the Vikingmuseum located at Roskilde in Denmark. There they told me that they built a replica of a Vikingship they had found in the Roskilde fiord. The nails were almost intact after 1000 years or so. When they should nail the replica together they couldn´t find nails in that quality, exept from a small American steel manufactory. They were the only one that could provide iron of that pureness as the old original nails were made of. It was almost 100% pure iron and there was almost none rust to them. They were of course also boiled in tar.
So the conclusion of this is: Today it´s probably to big of a cost to produce that sort of iron.

No doubt better steels can be made with today's technology. The question is why go to the expense and trouble when what they have works fine. I think the performance of a TI made today is just as good as one made 50 years ago. Would you want to pay say twice the price and get no increase in performance?

Good question Hajo.

For the most part that time period was the break point between the end of the cycle of "handmade" steels and the big industrial shops being run more scientifically.

Think of it this way. Sheffield steels were known for their quality worldwide and up the point where they stopped making fine cutlery steel in 100lb crucibles, there was a consistent effort to grade materials and reduce contaminants in the crucible before the smelt occurred. The other part of this problem is that metallurgical sciences were still fairly hit or miss as to which ingredients/alloys had an impact on the steel output. They all knew that Swedish ore was the best in the world (at the time) and that's still true, but simply because the native ore veins are without significant contamination by alloying elements that interfere with making a "clean" steel.

Now, moving past WWII when steel production ramped up considerably and recycling of old steels became routine. You can find all sorts of stuff on a chemistry specification sheet from a modern factory (40 ton ladle) production run that has no impact on the metal's specified intent according to the metallurgists working for the steel mill "it meets specs" for construction or for the customer's intended application. However, those minor alloying elements like old car parts etc, circuit boards and so forth that did not make it past the cleaning process at the recycling yard go into the ladle too.

The modern factory metallurgist accounts for those elements by adding others to the ladle for enhance deoxidation or to enhance the formation of the slags, e.g. draw out those contaminating elements that could alter the steel's specifications. This can be a very complicated ballet at the hot ladle, until the as-calculated-process is complete. One example is aluminium "killed" steel where Al is tossed in to the ladle in a known quantity and will really do a fine job of improving the melt, slag reduction, cleaning, and that specific amount is intended to be entirely burned away by the time they go to pour the ingots leaving none of the aluminium behind. Sometimes engineers do not realize that things don't work as they believe their textbooks tell them.

Flaws/cracks in the refractory coating of the ladle can trap small amounts of this or that and it works its way into the next pour and so on. My best friend purchase 10K pounds of a mill run to his specification, iron carbon etc. They delivered it to him and he went straight to the shop and made ten valuable blades (time/energy) and they all blew up in the heat treatment. He called for the spec sheet from the mill and there were things like Californium and odds and sods in there that no one would read as "clean" steel, but according to the metallurgist at the plant, "it met the intended specs" for iron and carbon and the other alloys that the textbook said would be equivalent to what he ordered. Except, at the practical application point of intended use, the entire heat treatment regimen had to be re-learned because all that crap, in such tiny amounts, changed everything.

Ullmencott has stated the other reason very clearly. It's too big of a cost to give a d*** about doing it right the first time. However, there are a few companies moving into the CPM world where the products are intentionally very clean, and expensive, and there are enough buyers who care to insist.

I've had a good deal of fun learning to make my own steel, as have some others, for purity's sake. It's a hard way to achieve what the steel mills could do if they were interested, but the only way I can control what they don't care about any longer.

Your assertion that it is philosophical is true and the explanation will be heavily weighted by economy of scale. Some of us still ask Why, even as we invest in the hard work of knowing how philosophy feels at the practical application point. d

What I heard about old steel is confirmed in the above post.
Old steel is purer, less impurities mean better quality of the edge, less prone to oxidation, may be even the heat treat process is easier to control and more consistent.

Hello All,

Thanks a lot for you comments and detailed explanations - it was great fun to read!
That the reason is the "curse" of recycling and is always "potentiating" sounds very plausible.
(do not understand me wrong - in principle recycling is the right way-IMHO... maybe not for Str8-steel
I also understand now the guy who is looking for old train axes to hammer out his knifes ( I saw this on TV). It is also interesting that "hardening process" must be learned/adapted again... - but it is like everything in modern times - compromise of money- or at least "money" is tipping the scale. If our community is getting bigger and bigger... we may become interesting for the steel mills...
Best Regards
Hajo

Scientific methods aren't necessarily superior to traditional craftmanship. Iron ore from different origins have different "contaminants", viz trace elements.

I have been told that modern iron is made using both iron ore and scrap iron and scrap metal, where they used pure iron ore in the past.

A chemist’s job is to locate or design an original formula that performs within specifications. Then modify that formula with less costly raw materials to increase profit margins and still remain in spec.

Originally Posted by Ullmencott

The quality of the old iron was wide higher than today.

This is interesting. I don't know much about metallurgy but ..... years ago I was doing ironwork (steel erection) in the Mesabi iron range of Minnesota. At that time, in the 1970s, taconite pellets were the iron ore being mined. This is a relatively low grade ore that used to be a waste product of the high grade hematite ore that was mined for the first 50 or so years of the iron range until it was depleted. In the '60s/'70s it became cost effective to process the taconite into pellets to be made into steel. Not the quality of the hematite though.

So what I'm getting at is it is quite possible that the raw ore available in the distant past was of a higher quality but was used up. Like I say, I don't know much about this topic, so I may be wrong.

The thread brings to mind the iron foundry 50 years ago in the town where I live. It used to be down town and the melt boss was a geezer. You told him what you wanted the metal for and he went out to the yard and collected ore, car springs, a particular engine block a batch of tin cans and some railroad ion and made a 500 lb melt to spec. It had a cupola furnace and it was fed from the top and air was injected at the bottom. Its design, while a continuous process, allowed spaces between melts on heat days.
The molds were hand rammed so they could do a one off if you wanted a prototype and had a wooden form a bit bigger than the part you wanted.
Those were the days! The foundry has moved out of town and now only works with CNC machined mold and maybe one guy knows how to ram a mold in a flask.
Link to old style foundry practice:
Foundry Manual
PS a lot of metallurgy there too!
~Richard