No, Vikings did not use cast iron as we know it today. The use of cast iron in Europe only became more prevalent around the 15th century, well after the Viking Age, which is generally considered to have occurred between the late 8th and early 11th centuries.
During the Viking Age, the primary materials used for their weapons, tools, and cookware were iron and steel. Iron was the more common metal, and it was obtained through a process known as bloomery smelting, which involved heating iron ore with charcoal in a bloomery furnace to extract the iron metal. The resulting iron was then forged and shaped into various objects.
While the Vikings did not have access to cast iron, they were skilled blacksmiths and were adept at working with iron and steel. They produced high-quality weapons, tools, and other artifacts using traditional forging techniques.
Cast iron production on a large scale emerged much later, with the development of blast furnaces and more advanced metallurgical processes in the late medieval period and the Renaissance. The widespread use of cast iron in various applications began to take off during the Industrial Revolution in the 18th and 19th centuries.