Praćenje proizvodnje i ispitivanje svojstava odljevaka od sivog lijeva kvalitete EN GJL-200

undergraduate thesis

• Title (english): Monitoring of production and casting properties investigation of EN GJL-200 quality of gray cast iron
• Author: Luka Zeljko
• Mentor: Zdenka Zovko Brodarac (mentor)
• Mentor: Franjo Kozina (pomoć pri izradi, neposredni voditelj)
• Mentor: Snježana Zeljko (pomoć pri izradi, neposredni voditelj)
• Committee member: Stjepan Kožuh (predsjednik povjerenstva)
• Committee member: Zdenka Zovko Brodarac (član povjerenstva)
• Committee member: Ivan Jandrlić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Metallurgy; Sisak
• Defense date and country: 2018-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Metallurgy

Abstract

Proizvodnja sivog lijeva složen je proces koji obuhvaća sve grane metalurgije i širok spektar aktivnosti. Prema potrebama tržišta te kvalitativnim i kvantitativnim zahtjevima pred gotovim proizvodom, sustavno se planira strategija proizvodnje i prema tome odabirekvaliteta materijala, ekonomski opravdana tehnologija proizvodnje, sastav uložnog materijala, tehnološka razrada procesa lijevanja i završna obrada odljevaka.
U eksperimentalnom dijelu praćen je postupak lijevanja i svojstva proizvoda: okvira vrata kamina od sivog lijeva kvalitete EN GJL-200. Praćena su svojstva kalupne mješavine namijenjene DISAMATIC® liniji za kalupovanje, kemijski sastav taline i parametri lijevanja te mehanička i mikrostrukturna svojstva odljevaka u sirovom (lijevanom) i površinski obrađenom (emajliranom) stanju.
Utvrđen je utjecaj visokih temperatura pri postupku emajliranja na promjenu mikrostrukture i mehanička svojstva odljevaka od kvalitete sivog lijeva EN GJL-200. Emajliranjem se povećava udio ferita, a dio perlita ide u ferit te se karbidi raspadaju. Utvrđene mikrostrukturne transformacije dovode do smanjenja vlačne čvrstoće i tvrdoće emajliranih uzoraka, ali i pojave duktilno-krhkog loma. Ne-emajlirani uzorci pokazuju krhki lom preko listića grafita i samo djelomično preko većinski feritne metalne osnove.

Abstract (english)

Gray cast iron production is a complex process involving all branches of metallurgy and a wide range of activities. According to the market needs and the qualitative and quantitative requirements of the final product, the strategy of production is systematically planned and therefore material quality, the economically justified production technology, the composition of the charge material, the technological elaboration of the casting process and the final surface treatment of the castings.
In the experimental part, the casting process and product properties were followed: the cast iron frame of gray cast iron quality EN GJL-200. The characteristics of the mould mixture used for the DISAMATIC® moulding line, the chemical composition of the melt, casting parameters, as well as mechanical and microstructural properties of castings in the raw (as-cast) and surface treated (enamelled) state were observed.
The influence of high temperature in the enamelling process on the microstructure change and obtained mechanical properties of gray cast iron EN GJL-200 was determined.Enamelling results in an increase in the ferite ratio in metal matrix, part of perlite transform into ferrite and carbides experience decomposition. Such microstructural transformation resulted in reduced tensile strength and hardness of enamelled samples, as well as mixed tough – brittle fracture. Non-enamelled samples show a brittle fracture across the graphite lamellas andpartially across the mostlyferritic metal matrix.

• Keywords: sivi lijev; emajliranje; mikrostruktura; mehanička svojstva
• Keywords (english): cast iron; enamelling; microstructure; mechanical properties
• Language: croatian
• URN:NBN: urn:nbn:hr:115:281050
• Study programme: Title: Metallurgy; specializations in: Metallurgical Engineering, Industrial Ecology; Course: Metallurgical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka metalurgije (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka metalurgije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-10-02 06:56:30