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1

An analysis of modified Jominy-test (JMC®-test)

Smoljan B., Iljkić D., Smokvina Hanza S., Traven F.

Archives of Computational Materials Science and Surface Engineering

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2009

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Vol. 1, nr 2

120-124

EN

Purpose: The performance and possibilities of application of modified Jominy-test (JMC®-test) in computer simulation of high-hardenability steel quenching were investigated. JMC®-specimen and cylindrical specimen has similar cooling curves if the cylindrical specimen has been quenched in oil or cooled in air. Design/methodology/approach: The performances of investigated JMC®-test have been estimated by comparison of cooling curves of JMC®-specimen and cylindrical one cooled in different quenchants. Findings: Based on the sufficiency of both, time of cooling and similarity of cooling curves of investigated workpieces and JMC®-specimen it can be concluded that JMC®-test can be accepted as very useful test for estimation of the hardness of quenched workpieces made of high-hardenability steels. Research limitations/implications: The cooling curves of JMC®-specimen and the cooling curves of cylindrical specimens have been given by computer simulation and more experimental researches are advisable. Practical implications: The simulation of quenching based on modified Jominy-test can be applied for steels with high hardenability. This method of simulation is especially suitable for tools and dies steels. Originality/value: Using the results of simple modified Jominy-test (JMC®-test) in numerical modeling of steel quenching it is possible to simulate hardness in quenched specimen of high-hardenability steel.

2

Results of cooling of dies with water mist

Pietrowski S., Władysiak R.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 25, nr 1

27-32

EN

Purpose: Intensification of die casting of car silumins wheels with use of the water mist instead of compressed air dies cooling in low pressure casting process were presented in the paper. Design/methodology/approach: Examinations of casting process parameters were carried out on the industrial workstation of casting car wheels under the low pressure and also with Magma computer simulating system. Findings: The temperature and the range of its variation were presented in characteristic points of the casting and the cooled die with use the compressed air and with the water mist. A scheme of the device for generating the water mist cooling the die and also the pictures of simulation of wheels casting process for researched cooling methods was given. Research limitations/implications: The manufacturing technologies with the permanent mould. Practical implications: Using the water mist to cooling of dies in die casting and low pressure casting process to intensify of cooling the die and to reduce the amount of casting spoilage. Originality/value: Using the water mist to cooling increases intensity of cooling of the die and the cast. It makes shorter the cycle of casting process as well as reduces the porosity of casts and increases mechanical properties: RP0,2, Rm, A5 and HB.

3

An analysing of heat treatment process planning

Smoljan B.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

563-566

EN

Purpose: Process planning of heat treatment has been investigated. The established approach of heat treating process planning is suitable for effective integration of heat treatment in computer added manufacturing. Design/methodology/approach: Process plan of heat treating process has been established based on fundamental process planning principals. The heat treatment was treated in the same as other manufacture processes. Findings: The general approach for process planning of heat treatment processes has been established. Heat treatment processes have to be designed into operations and sub-operations with the same principles that are also valid for other manufacturing processes. Research limitations/implications: The further research should be focused on development of methods for the better application of achieved results. Practical implications: This way of heat treatment process planning is more appropriate for integral trends of manufacturing, i.e., with the trend of introducing the modern systems in all parts of industrial manufacturing. Originality/value: The global approach of process planning of heat treatment processes was established and better unification with other manufacturing processes was achieved.

4

Przemiana gama->alfa w stopach Fe-30Ni po odkształceniu i oziębianiu

Ciura F., Ratuszek W., Bunsch A., Chruściel K., Czyrska-Filemonowicz A.

Inżynieria Materiałowa

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2002

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R. XXIII, nr 4

157-162

PL

Badano tekstury i mikrostruktury stopu Fe-30%Ni poddanego obróbce cieplno-plastycznej. W wyniku zastosowania specjalnej procedury przeróbki cieplno-plastycznej obejmującej walcowanie poprzeczne oraz oziębianie w ciekłym azocie uzyskano w tym stopie specjalną kompozytopodobną strukturę. Badania prowadzono wykorzystując metody dyfrakcji promieniowania rentgenowskiego. Analiza tekstur była oparta na obliczeniach funkcji rozkładu orientacji na podstawie eksperymentalnie zmierzonych figur biegunowych. Obserwacje struktury prowadzono wykorzystując techniki mikroskopii optycznej. Materiał w stanie wejściowym był jednofazowy i nie wykazywał obecności tekstury. Po walcowaniu do 30% odkształcenia w temperaturze otoczenia w stopie pojawiała się druga faza (martenzyt) powstająca w wyniku przemiany indukowanej odkształceniem. W odkształconym materiale obserwowano austenit o typowej teksturze oraz słabo steksturowany martenzyt. W następnej kolejności materiał walcowano poprzecznie w temperaturze 20 stopni Celsjusza oraz w temperaturze -30 stopni Celsjusza. Po takim odkształceniu tekstura austenitu ulegała wzmocnieniu, a dominującymi składowymi tej tekstury były orientacje {110}<001>, {110}<111> i {113}<332>. Równoczesnie udział martenzytu w stopie nieznacznie wzrastał. Po oziębieniu w ciekłym azocie przemiana zachodziła bardzo intensywnie, a tekstura martenzytu stawała się bardzo wyraźna z dominującymi orientacjami {557}<110> i {111}<110>. Na podstawie wyników eksperymentu stwierdzono, że przemiana austenitu w martenzyt była w tym stopie indukowana zarówno odkształceniem plastycznym, jak i szybkim oziębianiem. Obserwacje struktury i pomiary tekstur potwierdziły, że intensywniejsza była przemiana indukowana oziębianiem. Wykonano symulacje transformacji tekstury fazy alfa w teksturę fazy gama zgodnie z zależnością Kurdjumowa-Sachsa. Wskazują one, że tylko niektóre z orientacji obecnych w teksturze austenitu są dziedziczone w teksturze martenzytu, a ich transformacja zachodzi przy zachowaniu wariantu wyboru tylko niektórych spośród teoretycznie możliwych relacji pomiędzy fazami.

EN

In the present research the texture and microstructure of the Fe-30%Ni alloy after thermo-mechanical treatment were investigated. A specific composite-like structure was obtained by applying an appropriate mode and temperature of deformation with subsequent quenching in liquid nitrogen. Textures were measured by X-ray diffraction and their analysis was based on the orientation distribution function (ODF) computed from pole figures. Structure observations were carried out by means of optical microscopy. The initial texture of the single-phase (austenitic) material was nearly random. After 30% of rolling reduction at room temperature (20 degrees centigrade) the martensitic phase appeared within the structure due to the deformation induced gamma->alpha phase transformation. The austenite texture at the strain level was not very strong but typical, whereas martensite texture was very weak. Further 30% of plastic, deformation were imposed by applying "cross-rolling" at room temperature and at the temperature -30 degrees centigrade. After such procedure the texture of austenite become intensified and included following strong components; {110} <001>, {110} <111> and {113} <332>. Simultaneously the volume fraction of the martensitic phase slightly increased. After quenching in liquid nitrogen the texture of the alpha-phase was considerably sharpened with the major orientations {557} <110> and {111} <110>. From the experimental data it follows that the transitions from austenite (gamma) into the martensite (alpha) was first induced by plastic deformation and subsequently caused by rapid quenching in liquid nitrogen. Structure observations confirm the intensive development of the martensitic transformation during quenching. Simulated transformations were performed of the experimental texture (ODF) and major texture components (single orientations) of the alpha-phase into gamma-phase using Kurdjumow-Sachs orientation relationship. It was concluded that only selected components of the austenite texture were transformed and inherited in martensitic (alpha-phase) texture upon deformation and quenching according to so called variant selection.

5

Recent progress in the development of nanophase rare earth magnets.

Davies H.A.

Inżynieria Materiałowa

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2001

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R. XXII, nr 5

1001-1001