Utjecaj zaštitnog plina na mehanička svojstva metala zavara dobivenog primjenom žice SG 120

master's thesis

• Title (english): Influence of shielding gas on mechanical properties of SG 120 wire weld metal
• Author: Robert Hrgar
• Mentor: Ivica Garašić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2018-07-12, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

U prvom dijelu diplomskog rada obrađeni su razvoj, karakteristike i podjele čelika visoke čvrstoće s posebnim naglaskom na problematiku zavarljivosti takvih čelika. Opisane su osnovne značajke zavarljivosti takvih čelika i proučen utjecaj zaštitnog plina, unosa topline i sastava dodatnog materijala na mehanička svojstva zavarenog spoja. Također, istražena je i obrađena klasifikacija dodatnih materijala pri zavarivanju čelika visoke čvrstoće sukladno normi HRN EN ISO 16834:2012. U eksperimentalnom dijelu opisan je MAG postupak zavarivanja čelika API 5L X80 elektrodnom žicom LNM MoNi, kao i postupci ispitivanja, te analiza dobivenih rezultata. Planom pokusa definirane su dvije ulazne varijable, unos topline i vrsta zaštitnog plina, sa varijacijom na dvije razine. Provedeno je ispitivanje mehaničkih svojstava metala zavara statičkim vlačnim pokusom i ispitivanjem udarnog rada loma na Charpyjevom batu, kao i analiza makro uzorka. Eksperimentalni dio diplomskog rada proveden je u laboratorijima Fakulteta strojarstva i brodogradnje sveučilišta u Zagrebu.

Abstract (english)

The first part of the thesis deals with the development, characteristics and division of high strength steel with special emphasis on the problem of welding of such steel. The basic features of welding of such steel and the influence of protective gas, heat intake and the composition of the additional material on the mechanical properties of the welded joint are described. Also, the classification of additional materials for the welding of high strength steel in accordance with HRN EN ISO 16834: 2012 has been investigated and processed. The experimental section describes the MAG welding process of API 5L X80 LNM MoNi electrode wire as well as the test procedures and analysis of the obtained results. The experiment plan defined two input variables, heat inputs and types of protective gas, with two-level variation. An examination of the mechanical properties of weld metal by static tensile testing and examination of the impact toughness at Charpy's pendulum was carried out as well as a macro sample analysis. The experimental part of the thesis was conducted in the laboratories of the Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb.

• Keywords: čelici visoke čvrstoće; statičko vlačno ispitivanje; udarni rad loma; metal zavara
• Keywords (english): high strength steel; static tensile testing; impact touhhness; weld metal
• Language: croatian
• URN:NBN: urn:nbn:hr:235:265806
• 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: 2019-05-22 22:38:55