Trdnostne lastnosti kovaško varjenega jekla

Žos, Rok (author), Šturm, Roman (mentor)

Namen diplomskega dela je bil izdelati damaščansko kompozitno jeklo ter ga skovati v vzorce primerne za mehanske preizkuse. V diplomskem delu smo kovaško zvarili damaščansko jeklo iz jekel 15N20 in S235JR. Na pripravljenih vzorcih smo opravili udarni test žilavosti, upogibni preizkus, test trdote ter preučili mikrostrukturo. Vzorci so imeli različno število plasti in bili različno toplotno obdelani. Vzorci so bili kaljeni v olju, kaljeni v dveh sredstvih ter kaljeni v olju in popuščani v peči. Ugotovili smo, da trdota narašča s povečevanjem hitrosti ohlajanja in ne s številom slojev. Največji upogibni raztezek smo dosegli na vzorcu kaljenem v olju in na zraku ter ugotovili, da se vrednosti upogibnega raztezka zmanjšujejo z naraščanjem števila slojev kompozita.

• Language: Slovenian
• Keywords: maloogljično jeklo, evtektoidno jeklo, kovaško varjenje, trdota, udarna žilavost, mikrostruktura
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [R. Žos]
• Year: 2020
• Number of pages: XVIII, 45 str.
• PID: 20.500.12556/RUL-113498
• UDC: 621.791.42:669.14:539.4(043.2)
• COBISS.SI-ID: 17030939
• Publication date in RUL: 11.01.2020

Secondary language

• Language: English
• Title: Strength characteristics of metal welded steel

Abstract

The purpose of diploma thesis is to forge damascus composit steel and forge it into samples for mechanical tests. In my thesis we forge welded damascus steel from 15N20 and S235JR steels. On prepared samples we did Charpy impact test, deflection test, hardness test and studied the microstructure. The samples had different number of layers and were differently heat treated. They were quenched in oil, quenched in oil and air and some were quenched in oil and then tempered in furnace to release internal stresses. We figured out that the speed of heat treatment has the biggest influence on hardness. The highest value of deflection appeared when we heat treated the sample in oil and air. Deflection was decreasing when we increased the number of layers of composit.

• Keywords: low carbon steel, evtectoid steel, forge welding, hardness, impact toughness, microstructure