Microstructural changes in heat treatment of PM high-speed steels

Properly performed heat treatment can significantly affect final properties of high-speed steels, so the heat treatment parameters are chosen depending on the specific properties of the particular tool. Deep cryogenic treatment is carried out at a temperature of -196 °C (liquid nitrogen). By combining deep cryogenic treatments and various austenitization temperatures, which affects the volume of retained austenite, it is possible to affect the hardness and fracture toughness of tools and other steel parts. However, it may also affect the increase in wear resistance regardless of the increase in hardness. In addition, dimensional stability is achieved by transformation of residual austenite into martensite, eliminating the change in volume by 4%. This paper investigated the effect of deep cryogenic treatment on microstructures in high-speed steel produced by powder metallurgy in comparison to vacuum heat treatment

Smjerovna ovisnost izdvajanja antimona na površinama legura FeSi

The antimony surface segregation was investigated on surfaces of a polycrystalline Fe-Si alloy with 0.05 wt. % Sb, under UHV conditions, in the temperature range from 450 to 950 °C. The grain boundary segregation in experimental alloys was negligible. It was concluded that the texture formation results from orientation-dependent effects of antimony on the surface energy and through them on grain boundaries. Controlled surface segregation promotes the selective grain growth.Proučavano je površinsko izdvajanje antimona na površinama polikristalne legure FeSi sa 0.05 tež.%, u ultravakuumu i na temperaturama od 450 do 950 ◦C. Izdvajanje na granicama zrna je zanemarivo. Ustanovljeno je da je nastajanje teksture posljedica smjerovno–ovisnih učinaka antimona na površinsku energiju pa stoga i na granice zrna. Upravljavano površinsko izdvajanje potiče poseban rast zrna

EVALUATION OF ECONOMY PROJECT SOLUTIONS FOR BUSINESS – RESIDENTIAL FACILITIES

Že iz naslova projektne naloge lahko sklepamo, da bomo ocenjevali ekonomičnosti projektnih rešitev dveh poslovno stanovanjskih objektov. V poglavju 1 in 2 opisujemo namen naloge in izhodišča ter predstavljamo metodo, ki jo bomo uporabljali. V poglavju 3 predstavljamo in podrobneje opisujemo posamezna objekta. V poglavju 4 na praktičnih primerih izračunamo ter predstavimo metodo ocenjevanja ekonomičnosti, ki temelji na podlagi ocene vrednosti parametrov za lokacijske pogoje in projektno tehnične zahteve. Na podlagi pridobljene dokumentacije pripravimo izbor potrebnih podatkov, ki jih bomo uporabili za določevanje parametrov. Parametre nato primerjamo ter ocenimo. Posebej ne ocenjujemo tistih parametrov, pri katerih sta oba objekta enaka. Tako dobimo končno oceno ekonomičnosti projektnih rešitev. Oceno ekonomičnosti je smiselno uporabiti v dovolj zgodnji fazi projektiranja, torej v fazi izdelave idejnih projektov. V poglavju 5 je pripravljen izračun stroškovne vrednosti objektov.The aim of this paper is to evaluate the project economics of two residential-business buildings. Chapters 1 and 2 describe the purposes and the aims of the paper, as well as the used method. The presentation and a detailed description of the two projects are contained in Chapter 3. Chapter 4 describes the results of project economics assesment - an estimate based on the value of location conditions and project specification parameters, done on practical examples. The selection of necessary data, used for determining the parameters, is made on the basis of acquired project documentation. The parameters - excluding those which are the same for both projects - are then compared and evaluated. This gives us an overall estimate of the economics for the chosen project solutions. The project economics assesment is useful in the early stages of design - during the conceptual phase of the building projects. Chapter 5 contains the cost value calculations of the two projects

FEASIBILITY OF BUILDING EV FAST CHARGING STATION FOR ELECTRIC VEHICLES

Električna vozila so hitro razvijajoča tehnologija, ki predstavljajo potencialno trajnostno alternativo tradicionalnim vozilom z motorji notranjega izgorevanja. Z uporabo električne energije namesto fosilnih goriv, ta nova vozila zahtevajo nove sisteme infrastrukture, ki predstavljajo inovativne tehnološke investicije. Skozi magistrsko delo smo v empiričnem delu s pomočjo izdelave Načrta gradbenih konstrukcij za gradnjo dveh hitrih polnilnih postaj z večobdobno (dinamično) metodo IRR ugotavljali upravičenost graditev na mikrolokaciji. Za izdelavo kalkulacije stroškov investicije smo izdelali tehnično poročilo, projektantski predračun s popisom gradbenih del in grafične priloge. Z izvedenimi analizami trga EV, cenami električne energije, števila polnjenj na polnilnicah, kalkulacijo stroškov investicije, in predpostavljenimi prihodnjimi stroški in prihodki smo z metodo interne donosnosti izračunali upravičenost graditve hitrih polnilnih postaj, kar je predstavljalo osrednji del magistrskega dela. Kljub visokimi začetnimi vložki nam izračuni prikažejo rezultate, kateri niso upravičeni samo iz ekonomskega vidika, temveč tudi iz zasebnega.Plug-in electric vehicles are a rapidly evolving technology representing a potentially sustainable alternative to traditional internal combustion engine vehicles. By relying on electric power rather than petrol, these new vehicles will require a new infrastructure system for en-route charging options which represent innovative technological investments. Through the study in the empirical part, with using final Structural design of two DC fast charging stations and IRR method we determined eligibility of building fast charging stations on the micro location. Study also presents the approach of cost determination in terms of initial investment costs, and development of Technical report, Asset register and Designs. With market analyzes of EVs, electricity costs, average charging sessions per station, investment costs, assumptions of future costs and revenues, we determined eligibility of fast charging stations based on IRR method which was central part of our study. Despite the high initial investment costs, final results show us, that investments are not eligible just from an economic perspective, but also from social perspective