Special features of the production of low-alloy powder steel for structural and antifriction purposes

Conclusions The use of a minimal amount of plasticizer (not more than 0.5%) in the compacted charge and molds with additional drainage make it possible with a single compaction and sintering to obtain highly dense powder products — (7.2-7.3)·10³ kg/m³ — with a compacting pressure of 1000 MPa. Sintering of highly dense powder material ZhGr0,8D2N1 for 3.6 ksec is accompanied by its decompaction in consequence of degassing; extending the sintering time to 10.8 ksec reduces the porosity and improves the mechanical porperties of the products.The combination of the processes of sintering and hardening of rollers made of powder steel ZhGr0,8D2N1 in the plant Degussa makes it possible to obtain great hardness (of the order of 50–53 HRC) of products with a porosity of 5–10% after their cooling in oil. In comparison with existing technological processes, this one is distinguished by high productivity and degree of automation and mechanization; all this meets perfectly the requirements of mass production.Study of the refrigerating capacity of compressors confirmed the possibility of successfully using porous components operating in dynamic regimes under conditions of liquid lubrication, using capillary phenomena and the effect of hydraulic obliteration of fine communicating pore channels for lubricating the surfaces of friction pairs.Translated from Poroshkovaya Metallurgiya, No. 9(297), pp. 42–47, September, 1987.