19th-century European steel phosphorus and sulfur brittleness

Czechoslovakian steelmakers as among the best in Europe, but limited by high-phosphorus and high-sulfur iron ore. Used to introduce the role of manganese and basic refractories.

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.

The 1870s–1880s European steel quality problem (high phosphorus, high sulfur from low-quality coal) that Pennsylvania low-sulfur coal solved for U.S. producers and Spiegeleisen solved metallurgically.

You have your carbon steels, which traditionally — when Andrew Carnegie was selling to the railroads — were the cheapest; alloy steels would cost a little bit more. We don't have that kind of distinction anymore, we still call them carbon steels and alloy steels for historical reasons. Iron-carbon alloys — people found that just straight iron and carbon wasn't good enough, in the 1870s and 1880s, particularly in Europe, where they had a lot of phosphorus in their steel, and they had a fair amount of sulfur, which came from the quality of coal. They didn't have the really low-sulfur coal that you could get out of Pennsylvania. So the United States could make pretty good steel, but the Europeans were having problems. And someone found that if they added some Spiegeleisen — a German name for an iron-manganese ore, which had a lot of manganese in it — they would no longer have this problem with the sulfur.