Abstract
Steady increasing demands are being placed on the technological properties of long products made of stainless steels according to changed or new fields of application. The steel producer is endeavoured to meet these increasing demands on manufacturing and service properties by measures of the alloying technique or adjustment of the production conditions. Also on long products the conventional stainless steel grades are detached by new modern grades in a high degree – often with a lifted alloying content. On distinguishing examples the present level of processing thick sizes of stainless steels by Edelstahl Witten-Krefeld GmbH is presented.
About 90 % of the more than 600 steel grades comprising program (besides stainless steels also special engineering steels and tool steels) are today cast in a vertical continuous casting machine. The blooms with a cross section of 475 x 340 mm˛ were finally manufactured to forged and rolled products. A high process capability is attained by adjusted control of the casting and the process parameters within narrow ranges.
On distinguishing examples as the martensitic-ferritic steel X2Cr13, the martensitic age-hardening steel X5CrNiCuNb16-4, the duplex respectively superduplex stainless steels X2CrNiMoN22-5-3 and X2CrNiMoCuWN25-7-4 as well as non magnetizable steels and heating conductor alloys the successful production of continuously cast material is demonstrated. By controlling the production flow, properties are obtained with forged and rolled material in thickest sizes, which meet all requirements fixed for steel bars and tube rounds. The manufacturing of tube rounds in austenitic steel grades ensues in sizes up to 325 mm diameter alternatively to direct continuous casting. On martensitic steel grades the manufacturing in extremely big sizes is in trial.