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Visar resultat 1 - 5 av 16 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Evolution of artificial defects during shape rolling

    Författare :Mirjana Filipovic; Stefan Jonsson; Per-Olov Perä; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shape rolling; wire rod rolling; artificial defects; defect evolution; surface cracks; porosity; FEM; high speed steel; stainless steel; Other materials science; Övrig teknisk materialvetenskap; Initiering och utveckling av defekter under spårvalsning;

    Sammanfattning : Very often defects are present in rolled products. For wire rods, defects are very deleterious since the wire rods are generally used directly in various applications. For this reason, the market nowadays requires wire rods to be completely defect-free. Any wire with defects must be rejected as scrap which is very costly for the production mill. LÄS MER

  3. 2. The interdependence of plastic behaviour and final properties of steel wire, analysed by the finite element method

    Författare :Henrik Överstam; Magnus Jarl; Sven-Erik Lundberg; Chunhui Luo; Örebro universitet; []
    Nyckelord :Technology; FEM; defects; steel wire; wire drawing; rolling; forging; Teknikvetenskap; TECHNOLOGY; TEKNIKVETENSKAP; Maskinteknik; Mechanical Engineering;

    Sammanfattning : The finite element method (FEM) has been used in order to study the interdependence of plastic behaviour and final properties in steel wire. Three processes metal forming have been studied: billet forging, wire rod rolling, and cold drawing. LÄS MER

  4. 3. On impacts and ride-through of voltage sags exposing line-operated AC-machines and metal processes

    Författare :Fredrik Carlsson; KTH; []
    Nyckelord :Rolling mill; Blast furnace; Power Quality; Synchronous machine; Asynchronous machine; Voltage sag; Voltage interruption; Ride-through; Process disturbances; Simulation; Modelling;

    Sammanfattning : During the last decade, power quality has been recognised asa global problem. Among different types of power qualityproblems, voltage sags have been identified to be one of themost severe problems for different process industries. The mostcommon reason to voltage sags is lightning strikes in powerlines. LÄS MER

  5. 4. Some aspects on lubrication and roll wear in rolling mills

    Författare :Mohammed Tahir; KTH; []
    Nyckelord :strip rolling; lubricants; environment; roll wear modeling. Production campaigns; regression analysis;

    Sammanfattning : The thesis is focused on lubricants and roll wear in striprolling.Regarding lubricants, the possibility of introducing newones, which are less detrimental towards environment, isstudied in laboratory scale. This is done for cold rolling,both of an Al- alloy and a low carbon steel. LÄS MER

  7. 5. Modeling and Control of Plate Mill Processes

    Författare :Lars Malcolm Pedersen; Institutionen för reglerteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automatiska system; robotics; control engineering; Automation; Rolling Mill. Reheat Furnace. Modeling. Identification. Control.; robotteknik; reglerteknik;

    Sammanfattning : In this thesis two processes have been modeled and controlled, namely the plate thickness control and the slab temperature control. The classical solution for the thickness control problem can't handle asymmetric hardness variations and the estimation of the controlled output introduces stability problems. LÄS MER