Toplinska obrada alata za oblikovanje ispušnih cijevi

master's thesis

• Title (english): Heat treatment of tools for forming exhaust pipes
• Author: Miroslav Žalac
• Mentor: Božidar Matijević (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2021-12-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

Diplomski rad sastoji se od dva dijela: teorijskog i eksperimentalnog. U prvom (teorijskom) dijelu opisani su alatni čelici, njihova podjela, glavna svojstva te razlike između legirajućih i nelegirajućih čelika. Nakon toga detaljnije su opisani alatni čelici za hladan rad i njihova glavna podjela te pripadajuće toplinske obrade koje su se koristile u ovom radu. Također, opisani su strojevi i njihovi principi rada na kojima su se pripremali uzorci za toplinsku obradu. Isto tako, detaljno je opisana vakuumska peć u kojoj je proveden postupak kaljenja te ekscentar preša na kojoj se koristi alat iz ovog rada.
Eksperimentalni dio sastoji se od ispitivanja raznih postupaka toplinskih obrada kako bi se odredila optimalna svojstva za visoko-legirani ledeburitni Cr-V alatni čelik s dodatkom molibdena. Prije svega bilo je potrebno iz sirovine pripremiti uzorke postupcima obrade odvajanja čestica (glodanje, rezanje, brušenje) kako bi se dobilo 8 identičnih uzoraka za ispitivanje. Nakon toga provedena je toplinska obrada na istima koji su numerički označeni od 0 do 7. Uzorak „0“ označava osnovno stanje alatnog čelika (X155CrVMo12-1), dok su ostali uzorci podvrgnuti postupku kaljenja, a nakon kaljenja svaki uzorak je toplinski obrađen na drugačiji način kako bi se prikazale razlike među različitim postupcima toplinskih obrada.
Za kraj eksperimentalnog dijela ispitane su tvrdoće svih uzoraka na tvrdomjeru prema Rockwell-u te je izrađeni alat testiran u eksploatacijskim uvjetima u proizvodnji u tvrtki Auspuhu Lastovčić d.o.o.

Abstract (english)

The thesis consists of two parts; theoretical and experimental. The first (theoretical) part describes tool steels, their division, main properties, and differences between alloying and non-alloying steels. Following that, tool steels for cold work and their main division are described in detail, as well as the associated heat treatments used in this work. Also, machines and their working principles on which samples for heat treatment were prepared are described. The vacuum furnace in which the hardening process was performed and the eccentric of the bar on which the tool from this work is used is described in detail.
The experimental part consists of testing various heat treatment procedures to determine the optimal properties for high-alloy ledeburite Cr-V tool steel with molybdenum addition. First of all, it was necessary to prepare samples from the raw material by particle separation processing (milling, cutting, grinding) in order to obtain 8 identical samples for testing. After that, heat treatment was performed on them numerically marked from 0 to 7. Sample "0" indicates the basic state of tool steel (X155CrVMo12-1), while other samples were subjected to the hardening process. After hardening, each sample was heat-treated in a different way to show the differences between different heat treatment processes.
At the end of the experimental part, the hardnesses of all samples on the hardness tester according to Rockwell were tested and the manufactured tool was tested in operating conditions in production in the company Auspuh Lastovčić d.o.o.

• Keywords: toplinska obrada; alat; alatni čelik; X155CrVMo12-1
• Keywords (english): heat treatment; tool; tool steel; X155CrVMo12-1
• Language: croatian
• URN:NBN: urn:nbn:hr:235:358017
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-11-30 17:48:56