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1

Copper infiltrated high speed steel skeletons

Madej M.

Archives of Materials Science and Engineering

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2019

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Vol. 98, nr 1

5--31

EN

Purpose: This article is a monographic summary of the most important research results from the last 10 years regarding HSS based materials. This materias were produced with powder metallurgy technology using spontaneous infiltration. The presented results answer the question of how iron, tungsten carbide and copper additives influence the final properties of these materials and present additional microstructural phenomena revealed during their manufacture. Design/methodology/approach: Materials were produced by spontaneous infiltration. Porous skeletons for infiltration were produced by pressing and pressing and sintering of mixed powders. Copper was used as the infiltrant. Findings: The molten copper was drawn into the porous skeletons, through a capillary action, and filled virtually the entire pore volume to get the final densities exceeding 97% of the theoretical value. Research limitations/implications: As part of further research, microstructures of M30WC composites obtained by direct infiltration of copper into as-sintered porous skeletons using TEM are planned. Practical implications: Efficiant mechanical strength, high hardness, adequate heat resistance and good wear resistance of M3 type 2 HSS powder produced by woter atomisation make it an attractive material for manufacture of valve train components, for example valve seat inserts. Originality/value: The novelty in the article are the results of research on the microstructure made using TEM, the results of testing materials after heat treatment, untypical for highspeed steels. The article attempts to explain the influence of iron addition on properties - such a slight loss of mass as a result of its addition. The second aim of this work is to analyse the microstructural changes during sintering porous skeletons made from HSS with WC additions.

2

Structure and properties of HS6-5-2 type HSS manufactured by different P/M methods

Matula G., Dobrzański L. A., Herranz G., Várez A., Levenfeld B., Torralba J. M.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 2

71-74

EN

Purpose: It has been demonstrated in the paper structure and properties of high speed-steel HS6-5-2 type manufactured by different method of powder metallurgy. Design/methodology/approach: Light microscope, SEM, image analysis, hardness tests, density examination, transverse rupture strength tests, analysis of chemical composition by LECO apparatus. Findings: Basing on the investigations of the HS6-5-2 type high-speed steels reinforced with ceramics particles fabricated with Powder Metallurgy it was found of that density of sintered samples depend on reinforced particles, temperatures and atmosphere of sintering. Increasing of sintering temperature increase the density of sintering samples. Moreover the sintering under N2-10%H2 atmosphere produce samples with higher quality than using argon atmosphere and prevent of surface oxidation during sintering. Practical implications: The modern methods of powder metallurgy gives the possibility to manufacturing tool materials on the basis of high speed-steel which characterised very good properties with their final shape. Originality/value: In the paper the manufacturing by modern PM methods of tool materials on basis of high speed-steel manufactured carried out in order to improve the structure and properties of tool materials and to produce tools with their final shape.

3

Mechanical properties of high speed steel used in hot strip work rolls

Ziadi A., Meciridi M.A., Bouafia F., Belhenini S.

Advances in Materials Science

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2007

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Vol. 7, nr 2(12)

319-326

EN

The rolls in the finishing stands must have good resistance to both wear and fire cracks: The use of high-speed steel at the finishing stands has shown satisfactory results. The composition of this high-alloyed steel is an important parameter as the most significant change lays on the type, morphology, and volume fraction of the eutectics carbides. The heat treatment of these products consists of high temperature austenization followed by quenching and two temperings, as required in order to increase their overall hardness and to completely eliminate residual austenite. The influence of tempering temperatures on the mechanical properties of these products, determined using tensile, hot compression and fracture toughness tests, was studied in this research work. Their corresponding failure micromechanisms were defined by means of the analysis of fracture surfaces.

4

Structure and properties of FGM manufactured on the basis of HS6-5-2

Matula G., Dobrzański L. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

101--104

EN

Purpose: It has been demonstrated in the paper structure and properties of tool gradient materials manufactured by powder metallurgy on the basis of high speed-steel HS6-5-2 type. Design/methodology/approach: Light microscope, SEM, image analysis, microhardness tests, density examination. Findings: Basing on the investigations of the HS6-5-2 type high-speed steels reinforced with ceramics particles fabricated with Powder Metallurgy it was found that density of sintered samples depend on reinforced particles, temperatures and atmosphere of sintering. Increasing of sintering temperature increase the density of sintering samples. Moreover the sintering under N2-10%H2 atmosphere produce samples with higher quality than using argon atmosphere and prevent of surface oxidation during sintering. Practical implications: The Powder Metallurgy gives the possibility to manufacturing tools gradient materials on the basis of high speed-steel which characterised very high hardness on the surface. Originality/value: In the paper the manufacturing of tool gradient materials on basis of high speed-steel reinforced with hard ceramics particles carried out in order to improve the tool cutting properties.

5

Struktura i własności spiekanej stali szybkotnącej HS6-5-2 formowanej wtryskowo

Dobrzański L. A., Matula G.

Hutnik, Wiadomości Hutnicze

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2005

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Vol. 72, nr 3

187--194

PL

Na podstawie porównania struktury i własności stali szybkotnących HS6-5-2 wytwarzanych metodą formowania wtryskowego proszku, formowania niskociśnieniowego, prasowania i spiekania oraz stali komercyjnych wytwarzanych metodą ASEA-STORA stwierdzono, że w strukturze wszystkich badanych stali szybkotnących w stanie spiekanym występują drobne węgliki równomiernie rozmieszczone w osnowie stali. Zastosowanie atmosfery zawierającej azot podczas spiekania, powoduje formowanie się drobnych, sferycznych węglikoazotków typu MX, trwałych w wysokiej temperaturze spiekania i austenityzowania. Wspólną zaletą stali formowanych wtryskowo oraz niskociśnieniowo jest szerszy zakres temperatury spiekania w stosunku do stali wytwarzanych przez tradycyjne prasowanie i spiekanie, dla których wynosi zaledwie 5 °C. Stale formowane niskociśnieniowo charakteryzują się najniższą temperaturą spiekania oraz najwyższą gęstością, wynikającą z wysokiego stężenia węgla pochodzącego z procesu degradacji lepiszcza. Dodatkowo wyższe stężenie węgla powoduje zwiększenie udziału austenitu szczątkowego i niższą twardość po hartowaniu i odpuszczaniu. Stal formowana wtryskowo w stanie obrobionym cieplnie osiąga twardość porównywalną do twardości stali komercyjnej typu ASP 23, wskazując na zasadność stosowania metody formowania wtryskowego proszku do wytwarzania stali szybkotnących. Formowanie wtryskowe proszku umożliwia wytwarzanie narzędzi na gotowo, tj. z pominięciem obróbki plastycznej i ubytkowej, koniecznej w przypadku stali typu ASP 23. Ponadto czas procesu degradacji i spiekania stali formowanych wtryskowo jest o ok. 10h krótszy niż stali formowanych niskociśnieniowo, co jest spowodowane zastosowaniem lepiszcza dwuskładnikowego.

EN

On the basis of comparison of structure and properties of high-speed steels HS6-5-2 manufactured by Powder Injection Moulding, Pressureless Forming, compacted and sintered andproduced by comercial ASEA-STORA method it has been shown that the structure of all examined high-speed steels in sintered state are small and spherical carbides uniformly distributed inferrite matrix. The use ofatmosphere with nitride during sintering process cause formation of the small and spherical carbonitrides MX type stable in high temperaturę of sintering and austenitizing in steel matrix. The common feature of steel formed by Powder Injection Moulding and Pressureless Forming is broaden range of sintering temperaturę in relation to steels produced by conventional compacting and sintering which equals only 5°C. Steels formed by Pressureless Forming are characterized by the lowest sintering temperature and the highest density resulting from high carbon content coming from thermal debinding process of a binder. Moreover, higher carbon concentration causes increase of the retained austenite portion and lower hardness after quenching and tempering. The steel formed by Powder Injection Moulding and heat treated obtain comparable hardness to hardness of commercial ASP 23 steel showing the reason of high speed steel manufacturing by Powder Injection Moulding. The Powder Injection Moulding makespossible production of final shape tools without plastic working and machining which is necessary in case of ASP 23 type steel. Moreover time of thermal debinding and sintering process of steels formed by Powder Injection Moulding is about 10 h shorter than steels formed by Pressureless Forming because two-component binder application.