FLAT STEEL PRODUCT FOR LIGHT-WEIGHT STEEL SECTIONS

摘要

1343183 Composite sheet steel ROHRKOMBINAT STAHL-UND WALZWERK RIESA VEB 7 June 1971 19177/71 Heading E1K Composite sheet steel intended for cold working to produce sections, e.g. angle iron, or welded tubes, consists of an inner layer of high tensile steel, e.g. 0.31 per cent carbon content, surrounded by an outer layer of soft steel, e.g. of 0.10 per cent carbon content, the inner layer being discontinued short of the lateral edges of the sheet so that these edges are of the softer steel throughout their thickness to facilitate welding. The preferred compositions of the two layers are as follows:- inner layer: C=0.31%, Si=0.27%, Mn= 1.58%, P=0.15% S=0.032%, remainder Fe; outer layer: C=0,10%, Si=0.25%, Mn= 0.55%, P=0.030%, S=0.042%, remainder Fe. The outer layer comprises 25% to 35% of the total cross-section. It may be of a corrosion-inhibiting steel or a steel suitable for surface refinement.