Czechoslovak high-phosphorus ore steel cracking

Co-anchored with the prior case. Specifically the cracking-on-forge problem and the manganese-ore remediation.

Student: [question about historical European steel quality]

In the United States we had some iron ores very low in phosphorus, and so we could make good steel. The Czechoslovakians were some of the best steelmakers in Europe, and their iron ore had a lot of phosphorus and sulfur. They could not get consistent results. It wasn't until John Chipman came along in the 1940s that people were really taught how to get consistent results. You don't just take iron and carbon and put them together. You put them together with a flux, and that flux might be limestone, it could be calcium silicate — which the geologist calls wollastonite, just a rock. They might throw sand in there. They throw these different things into the steel when they're making the cast iron, which you're going to then turn and burn the carbon off to make steel out of.

Tom credits a Czech manganese-bearing ore for enabling sulfur tolerance in early steelmaking. *Note: this may be a different incident from the canonical cluster, which is phosphorus-related. Flagged for cluster reconciliation.*

The early iron industry could not make good steel until they found a certain ore in Czechoslovakia that had high manganese in it. Of all the elements in the periodic table, the only element that will tie up the sulfur impurity in the steel is manganese. Manganese sulfide melts at a higher temperature than the melting point of iron, just barely. Otherwise you end up getting liquid iron sulfide at the grain boundaries. You try to heat it up to roll it and it's like trying to roll a Slurpee — it's got a liquid grain boundary with solid grains, it doesn't work. But steel can be made, and is made, in virtually any part of the world.