Improvement of Mechanical Properties of Sintered Composite Stainless Steel by Means of Rolling

An experimental study has been conducted to improve the mechanical properties of sintered stainless steels of SUS304L and SUS430L powders by means of such treatments as cold-rolling-and-annealing or hot rolling. The results obtained are as follows.(1) Through 60% coldrrolling and 2-hour annealing at 1 200°C, the relative density of both sintered steels has reached about 96%, and their tensile strength and elongation have closely approached the usual values of the corresponding cast steels.(2) In the sintered steels from mixed powder, the martensite produced in the interface between SUS304L and SUS430L has a great effect on the mechanical properties. The martensite is most produced in the sinter of the 50% volume fraction of SUS304L, thus the tensile strength is the highest and the elongation is the lowest. In the tensile test above 700°C, the effect of martensite disappears.(3) A treatment of 60% hot rolling at 1 100°C improves tensile strength and elongation compared with the above cold-rolling-and-annealing treatment.