Cement steel
Cement steel is a historical type of steel that was obtained through cementation (historical name: cementing ). For this purpose, iron rods were layered in special boxes surrounded by a powder consisting of coal and other substances and made to glow for a long time in an oven in the absence of air. This process (often also called "carburizing") increased the carbon content considerably, but was laborious and expensive, and you could only produce a relatively small amount of steel in one "fire". In addition, the process was heavily dependent on the quality of the iron used. It therefore quickly lost its importance in the 19th century after the puddling process emerged .