20th International Forgemasters Meeting - IFM 2017

Steel cleanliness is an important quality characteristic, which becomes more and more important since the invention of secondary metallurgy in the most steel mills. The question is: What are the main influencing parameters? This paper describes several influences on the macro cleanliness of big forging ingots. Some of them like the runner system refractory, the mould powder, ladle refractory are directly linked to the macro cleanliness. Others like the cast iron parts, pouring rate, casting temperature, hot top treatment and argon shrouding representing the process parameters. A third group is maybe not directly connected to the ingot but shows also significant importance. For example staff training, the teeming equipment and data recording belong to this group. Referring to the mentioned parameters a quality inspection of all used materials, processes and standards are essential for good macro cleanliness. With numerous projects and improvements over the last ten years Breitenfeld Edelstahl generated the knowledge to produce ingots for the highest technical requirements. The results of more than 6000 metallurgical investigated ingots lead to the answer: Pay attention to every individual parameter for ideal results in macro cleanliness.