What are the raw materials of carbon steel flanges?

What are the raw materials of carbon steel flanges?
According to the manufacturing method of carbon steel flange, the raw materials used are different
  1: forging; ;
The raw materials used for forging carbon steel flanges are divided into the following categories: high-quality round steel, continuous casting billets produced by large steel mills. , ingots of the intermediate frequency furnace.
  2: Steel plate cutting
Steel plate cutting generally uses steel factory steel plate fixed-length material plate, old ship plate, machined part material edge
  3: Casting.
Cast carbon steel flanges are made of iron filings and high-quality Q235 scrap steel, which are directly converted into molten iron and then cast.