PM High Speed Steels Research Articles

Algunas observaciones sobre la sinterización del acero austenítico 316L en atmósfera de argón

PM high speed steels are prone to higher corrosion rates due to residual porosity as well as chromium depletion of the matrix during sintering AISI 316L powders have been cold compacted (100-1,000 MPa) and sintered (1,000-1,250°C, 15-240 min) under several argon containing or vacuum atmospheres. Better densification rates can be achieved as sintering time or temperature increase in the presence of argon. No surface oxidation has been observed with the use of low pressure argon atmospheres, as long as samples are protected in a stainless steel partially sealed container.

Wear behaviour of a PM high speed steel product : S.Ashok et al. (Sundram Fasteners Ltd, India.)

Rare earth magnets have been used in prosthodontics, but their tendency for corrosion in the oral cavity and insufficient attractive forces limit long-term clinical application.The purpose of this study was to evaluate the attractive force of different types of new-generation magnetic attachment systems.The attractive force of the neodymium-iron-boron (Nd-Fe-B) and samarium-cobalt (Sm-Co) magnetic attachment systems, including closed-field (Hilop and Hicorex) and open-field (Dyna and Steco) systems, was measured in a universal testing machine (n=5). The data were statistically evaluated with 1-way ANOVA and post hoc Tukey-Kramer multiple comparison test (α=.05).The closed-field systems exhibited greater (P<.001) attractive force than the open-field systems. Moreover, there was a statistically significant difference in attractive force between Nd-Fe-B and Sm-Co magnets (P<.001). The strongest attractive force was found with the Hilop system (9.2 N), and the lowest force was found with the Steco system (2.3 N).The new generation of Nd-Fe-B closed-field magnets, along with improved technology, provides sufficient denture retention for clinical application. (J Prosthet Dent 2011;105:203-207)

The influence of primary carbides and test parameters on abrasive and erosive wear of selected PM high speed steels

The aim of this investigation has been to further the understanding of the contribution given by the primary carbides to the abrasive and erosive wear resistance of six HSS's, and to evaluate different test methods. With abrasives significantly harder than the primary carbides of the HSS's, two- and three-body abrasion rates showed only small variations with primary carbide volume fraction, size and type. However, using abrasives/erodants softer than the carbides the qualitative results were similar for the two- and three-body abrasion tests and for the erosion test, with the wear resistance increasing with the volume fraction primary carbides.

Wear and Mechanical Behaviour of PM High Speed Steels with Carbide Reinforcement

Wear and Mechanical Behaviour of PM High Speed Steels with Carbide Reinforcement

Heat treatment of PM high speed steel based metal matrix composites : J. Bolton, A.J. Gant (University of Bradford, Bradford, UK)

Heat treatment of PM high speed steel based metal matrix composites : J. Bolton, A.J. Gant (University of Bradford, Bradford, UK)

Heat treatment of PM high speed steel based metal matrix composites : J. Bolton, A.J. Gant (University of Bradford, Bradford, Yorkshire, UK)

Heat treatment of PM high speed steel based metal matrix composites : J. Bolton, A.J. Gant (University of Bradford, Bradford, Yorkshire, UK)

Cutting performance of PM high speed steels containing microcrystalline powders

The hardness, wear behaviour and microstructure of AISI M2 high speed steel implanted with carbon ions are discussed. The samples were implanted at an energy of 100 keV. The doses ranged from 1×1017 C+/cm2 to 3×1018 C+/cm2. Hardness increases due to ion implantation, but no significant dose dependence is found. For lower doses the wear effects mainly the pin, but from doses of 5×1017 C+/cm2 onwards a pronounced ploughing of the disk is observed. The abrasive wear rate decreases with increasing dose. Microstructural investigations reveal the presence of ε-carbide and graphitic carbon in the implanted volume. A possible correlation between hardness and wear is discussed based on the microstructural results.

Effect of vanadium carbide content and alloying technique on PM high speed steel: H. Chung et al (Korea Inst. of Machinery and Metals, Kyungnam, Korea)

Effect of vanadium carbide content and alloying technique on PM high speed steel: H. Chung et al (Korea Inst. of Machinery and Metals, Kyungnam, Korea)

Reacting and stability of carbide and solid lubricant additions to PM high speed steel: J.D. Bolton, A.J. Grant (Bradford University, Bradford, UK), Powder Metallurgy, Vol 36, No 4, 1993, 267–274

Reacting and stability of carbide and solid lubricant additions to PM high speed steel: J.D. Bolton, A.J. Grant (Bradford University, Bradford, UK), Powder Metallurgy, Vol 36, No 4, 1993, 267–274

Effects of carbide size on properties of hot extruded PM high speed steel : A. Murase, G. Abe (Sanyo Special Steel Co Ltd, Himeji, Japan)

Effects of carbide size on properties of hot extruded PM high speed steel : A. Murase, G. Abe (Sanyo Special Steel Co Ltd, Himeji, Japan)

熱間等方圧加圧（ＨＩＰ）利用技術の研究開発

Hot isostatic pressing technology has been applied to produce new materials with high performance using gas atomized alloy powders as raw materials. The author has been studying the technology in order to extend the application field for a long time. High speed tool steels and alloy tool steels, bimetallic products lined with corrosion and wear resistant alloy powders, heat resistant superalloy disks etc. are described.Mechanical and physical properties of PM high speed steels with and without a large amount of nitrogen were evaluated in comparison with conventional steels so that the difference in the roles of nitrogen and carbon in the steels and in the manufacturing processes could be made clear. The manufacturing process of bimetallic cylinders and valves and the alloy design of lining, especially the effects of alloying elements. in Co and Ni base alloys are discussed. As-HIP and HIP plus isothermal forging of superalloy disks were studied and isothermal forging of dual property disk made of different powders was also described.

Comparison of PM and conventional high speed steels: M. Miskovicova et al (Ustav Materialoveho Vyskumu SAV, Kosice, Czechoslovakia), Pokroky Psaskove Metalurgie, No 1–2, 1992, 68–86. (In Czech)

Comparison of PM and conventional high speed steels: M. Miskovicova et al (Ustav Materialoveho Vyskumu SAV, Kosice, Czechoslovakia), Pokroky Psaskove Metalurgie, No 1–2, 1992, 68–86. (In Czech)

ＷＣｏＢ系硬質合金の組織と機械的特性におよぼすＣｒ添加量の影響

Effects of Cr on the mechanical properties and phase formation of WCoB base alloys were studied using the model alloys whose compositions were Co-1.93mass%B-33.3mass%W-(0-20)mass%Cr. The new alloys consist of a WCoB type ternary boride as a hard phase and a cobalt base binder alloyed with Cr, W and other elements, both of which are formed by reaction boronizing sintering.The transverse rupture strength (TRS) of the alloys depended strongly on the microstructure, which varied significantly with Cr content. The highest TRS of 2.85GPa obtained at 15mass%Cr was attributed to the refinement and good distribution of WCoB boride. Moreover, the TRS of the alloy with 15mass%Cr still kept a value of about 1.8GPa at 1173K. The weight gain of the alloy oxidized in air at 1173K was less than that of SKD11 and close to that of SUS304.Corrosion resistance of the alloys in a non-oxidizing 10mass% HCl solution was better than those of a PM high speed steel, stainless steels such as JIS SUS 405, 440C, 316L and 304 and a tool steel JIS SKD11, and close to that of Hastelloy C. On the other hand, in an oxidizing 10mass% HNO3 solution the alloys showed better corrosion resistance than a cemented carbide of WC-10mass%Co, a PM high speed steel and SKD11, and were almost same as stainless steels and Hastelloy C.

Effect of steel cleanliness on fracture of PM high speed steels (HSS) and tool steels: P.H. Hasselstrom, W. Roberts (Soderfors Powder AB, Soderfors, Sweden)

Effect of steel cleanliness on fracture of PM high speed steels (HSS) and tool steels: P.H. Hasselstrom, W. Roberts (Soderfors Powder AB, Soderfors, Sweden)

New PM high speed steel cutting tool and wear resistant materials: J.M. Bolton et al, (University of Bradford, UK)

New PM high speed steel cutting tool and wear resistant materials: J.M. Bolton et al, (University of Bradford, UK)

Defects in PM high speed steels: G.IL. Parabina, L.N. Marchenko. (Scientific Research Inst. for Special Steel, Kiev, Ukraine), Stal, No 4 1991, 70–72. (In Russian)

Defects in PM high speed steels: G.IL. Parabina, L.N. Marchenko. (Scientific Research Inst. for Special Steel, Kiev, Ukraine), Stal, No 4 1991, 70–72. (In Russian)

Application of W-free low Co PM high speed steel (HSS) for hard facing of cutting tools: G.E. Titenskaya et al, Poroshkovaya Metallurgiya, No 11, 1990, 101–104, (In Russian)

Application of W-free low Co PM high speed steel (HSS) for hard facing of cutting tools: G.E. Titenskaya et al, Poroshkovaya Metallurgiya, No 11, 1990, 101–104, (In Russian)

Niobium in PM high speed steels

PM processing allows high levels of niobium to be used in high speed steels. This forms highly stable carbides offering a wide corridor for heat treatment. The article shows how HSS with excellent wear resistance and cutting performance can be achieved.

PM high speed steels enriched in C, V and Ti

Two modified T15 type high speed steel powders enriched in carbon, vanadium and titanium were produced by the rotating electrode process and consolidated by extrusion. The chemical compositions of these modified steels were 2.66C13.3W4.6Cr9V5.3Co and 2.26C13.4W4.6Cr4.1V5Co0.73Ti for grades called T159V and T150.7Ti respectively. The hardening, the tempering response, the cutting performance and the flexural strength of these experimental high speed steels were assessed and compared with a conventional T15 grade. The T150.7Ti grade displayed a better cutting performance than the conventional T15 grade whereas the cutting performance of the T159V grade was significantly lower.

Properties and applications of modified PM high speed steels in wear resistant situations: Henry, R.J. and Brewin, P.R. Met. Powder Rep. Nov. 1989 44, (11), 763–767

Properties and applications of modified PM high speed steels in wear resistant situations: Henry, R.J. and Brewin, P.R. Met. Powder Rep. Nov. 1989 44, (11), 763–767