This year, it is one hundred years since stainless steel was manufactured for the first time at Sandvik and in Sweden. After the first melting in April 1921, Sandvik started regular tube production, followed by wire and strip.
Stainless steel was a good complement to Sandvik's product line at the time. The steel laboratory was enlarged to prepare for the new steel grades together with other production investments. A period of expansion and investments followed.
In 1930, the steel mill's cold-rolling operations were completely rebuilt, inside and out. Even a sintering plant and new electrical arc furnaces were set up. This became the breakthrough of stainless steel.
At this point, in the early 1930s, Sandvik had 30 different grades of stainless steel in production. In 1932, Sandvik acquired an exclusive Nordic license related to cold rolling of steel tubes using the pilgering method for 60,000 dollars. This process, further developed by Sandvik's metallurgists, made it possible to reduce both the outer diameter and the thickness of the tube material in a single rolling operation. This meant a significant rationalization because a single operation could replace several cold drawings in the earlier method, and the resulting quality was even better.
What does this mean for us today?
"Even though we have modernized the equipment from those days, and added processes like continuous casting and extrusion, some of the fundamental processes like pilgering, ingot rolling and forging are the same", says Tom Eriksson, VP & Head of Strategic Research at Sandvik Materials Technology.
"Today, we have some 900 different active stainless steel recipes in our library, although many of them are varieties with minor differences, and not all are melted on a regular basis. In a normal year, we produce roughly 200 different alloys in our melt shop", he says.
Sandvik Materials Technology is today most known for its advanced duplex stainless steels, that is a steel with a combined ferritic-austenitic structure that performs well in any application including chlorides. These are typically alloyed in a way that makes them quite difficult to produce and heat-treat.
If you are interested, you can read more about duplex stainless steel in this article by Mark Newman: Sandvik and the history of duplex