CS220283B1 - Method of manufacturing flat bodies exposed to friction,by powder metallurgy processes - Google Patents

Description

SOCIALIST REPUBLIC OF CZECHOSLOVAKIA (19) DESCRIPTION FOLLOWING COPYRIGHTWAREW 220283 (11) (Bl) (51) Int. Ci.3 B 22 F 5/08 (22) Enrolled 36 10 81 (21) (PV 7810-81) (40) Other 27 08 82 INVENTIONS AND DISCOVERIES (45) Issued 15 02 86 (75)

THE INVENTOR OF SALAK ANDREJ img. CSc., KOŠICE (54) Method for the production of flat bodies by powder) metallurgy, operating under trenla 1 conditions

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for the manufacture of steel flat bodies by powder metallurgy processes operating under conditions of temperature, such as, for example, axial ball bearing rings and spur gears.

According to the current powder metallurgy procedures, flat bodies, friction working components are produced in such a way that a molded part is pressed by means of a molded or pre-alloyed powder, corresponding to the chemical composition, with a sintered material. After sintering, depending on the final properties of the component, even though it is still porous, it can be heat-treated or heat-treated and grinded. In the case of requirements for the porous state of the component, which is most often the case, the porous sintered teleform is usually broken down by forging in closed instruments. This will also ensure that the required shape and dimensions of the component are achieved. Thereafter, the component is thermally or chemically-heat-treated, usually followed by sanding. According to the friction conditions under which the component operates, the hardness of the material is usually to be achieved in the range of 40 to 65 HRC by thermal or chemical co-heat treatment. The results of the analysis of breakage of parts operating predominantly under the conditions of rolling friction, such as, for example, roller bearing rings and toothed wheels, indicate that the occurrence of faults in such components only occurs predominantly by contact stress in the subsurface layer of the material. exceeding 1 mm.

A drawback of the prior art in the manufacture of steel flat bodies by powder metallurgy processes is that a higher alloy powder is always used to produce the entire component according to the requirements for achieving the highest properties even though the failure occurs only in a layer of ridge not exceeding 1 mm, only on the functional side of the component. Accordingly, for other components, such high characteristics are not required, characterized in particular by hardness.

This drawback removes the need for the manufacture of flat bodies by powder metallurgy processes operating under the conditions of the invention, wherein the iron powder layer, optionally with the addition of at least one of a group of elements comprising Mn, is incorporated into the sanasype die. Cr, Si, P and Cu, then a top layer of powder alloyed on at least two groups of elements, including W, Co, Ti, V, Ni, Mo, Cu, Mn, Cr, Si and P, is poured onto the bottom powder layer in both 220283

Claims (2)

SUBJECT Method for producing flat bodies by powder metallurgy processes operating under friction conditions, characterized in that iron powder is introduced into the pressing tool, optionally with the addition of at least one of a group of elements comprising Mn, Cr, Si, P and Cu, then the upper layer of powder alloyed with at least two of the group of elements comprising W, Co, Ti, V, Ni, Mo, Cu, Mn, Cr, Si and P is poured onto this lower layer, in solid form, then the powdered batch is processed by pressing and sintering, optionally further forging in closed tools. 2. A method according to claim 1, wherein the weight of the upper layer of the higher alloyed powder is 30 to 100% by weight of the powder of the lower layer, provided that the sum of the weight of the upper and lower layers of powder is equal to the desired weight of the whole body.