Preparation technology of carbide steels

Kinetic dependences of the average particle size of carbides and steels during milling in an attritor are investigated. The volume content of various fractions in the powders under study is established. The technology of preparing the powder charges for the acquisition of carbide steels 40X2-B₄C, P6M5K5-TiC, and X18H15-Cr₃C₂ used in the production of machine building wares operating under conditions of increased wear, high temperatures, and corrosion media is presented.     

Structure and properties of an R6M5K5 high-speed steel-titanium carbide composite in the form of a hot-forged bilayer product

The structure of a bilayer powder composite consisting of a working wear-resistant layer (carbidosteel) based on R6M5K5 high-speed steel with disperse titanium carbide inclusions and of a substrate made of a plain carbon steel is studied. This carbidosteel is fabricated by hot forging of powder workpieces. The structures of the hot-forged and sintered steels in the zone of steel-titanium carbide interaction are compared. The physicomechanical properties and wear resistance of a bilayer product with a wear-resistant carbidosteel layer produced by hot forging are estimated and compared to carbidosteels produced by other methods.     

Hot Pressing Technology to Produce Wear-Resistant P/M Structural Materials with Dispersed Solid Inclusions

We have examined the possibility of milling iron, nickel, chromium, high-speed steel, and titanium carbide powders in an attritor (attrition mill) for use in producing carbide steel. The powders were milled to a particle size of 1–3 μm for TiC and 10 μm for metal components. As a rule, such powders and mixture of powders do not flow or form, which makes it impossible to produce blanks for hot pressing by the traditional die pressing method. Shells pressed from iron powders are proposed for forming a blank. We tested techniques for hot pressing dispersed powders into such envelopes. __________ Translated from Poroshkovaya Metallurgiya, Nos. 7–8(444), pp. 43–50, July–August, 2005.     

Milling of Carbide-Steel Powder Components and Their Mixtures in an Attrition Mill

Milling of wear-resistant steel and titanium carbide powders is studied with an attrition mill rotation rate of 980 rpm. The physical and technological properties of powders and particle size are determined. Particle shape and the change in material chemical composition during milling are studied. It is established that steel powder cannot be milled to particle sizes less than 3.6 μm whereas a mixture of steel and titanium carbide can be milled to a fine state (0.3 μm). Powders with a size of about 1 μm neither flow nor are formable. Use of benzene as a milling medium makes it possible to prevent steel powder oxidation, but the carbon content in titanium carbide decreases. During milling of the main part of the charge to a fine state rather large steel particles (up to 50 μm) remain.     

Development of powder material hot forging in the ukraine

Information about the chemical composition, physical, mechanical, and operating properties of structural, tool, electrical, and magnetic materials synthesized by hot forging is analyzed. Numerous materials are used for making articles for rocket technics, machine tool building, agricultural engineering, apparatus, and railway transport. Production processes for synthesizing materials and manufacturing articles with an indication of the optimum parameters for production operations are described. The scientific organizations and industrial enterprises of the Ukraine that specialize in hot forging of powder materials are indicated. Translated from Poroshkovaya Metallurgiya, Nos. 3/4(412), pp. 84–104, March–April, 2000.