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Various types of case-hardening grade sintered steels containing Mo, CrMo, and Ni-Mo were manufactured by compacting at 200 - 800 MPa and sintering. The sintered samples were then low-pressure carburized, the equipment and conditions being selected as standard for wrought steel grades and low alloyed, sintered steel grades with high density. Temperature was 930°C, propane and acetylene were used as carburizing agents, and gas quenching was performed. It showed that carbon pickup strongly depends on density as well as on the alloy elements, being enhanced by the used of acetylene and higher porosity as well as by the presence of higher contents of Cr and Mo. Especially with 3 % Cr steels of low density, pronounced overcarburization occurred, and most of the specimen volume was transformed into carbide. At higher density levels, this effect was less pronounced, although in most cases the microhardness profile showed two maxima, one at the surface and the other within the material. The former was caused by formation of carbide and the latter by martensite formation while in between a mix of martensite, retained austenite, and some carbide resulted in a comparatively soft microstructure. Mo and Ni-Mo steels were less sensitive to overcarburization. By a solution treatment at 1000°C, more regular hardness profiles were obtained in the Cr-Mo steels if overcarburizing had not been too pronounced. In all cases, however, defined cases were obtained, the through carburizing commonly observed with porous sintered steels apparently being avoided by the low-pressure treatment. This technique thus seems to be well suited for case hardening of sintered steels if the carburizing parameters are accordingly adapted.