{"id":6265,"date":"2026-10-19T09:48:42","date_gmt":"2026-10-19T09:48:42","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-velaverkfraedi-andri-isak-thorhallsson\/"},"modified":"2026-10-19T09:48:42","modified_gmt":"2026-10-19T09:48:42","slug":"doktorsvorn-i-velaverkfraedi-andri-isak-thorhallsson","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-velaverkfraedi-andri-isak-thorhallsson\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed v\u00e9laverkfr\u00e6\u00f0i – Andri \u00cdsak \u00de\u00f3rhallsson"},"content":{"rendered":"
\n
\n

<\/strong>V\u00f6rninni ver\u00f0ur streymt<\/a><\/p>\n

Doktorsefni:<\/strong>\u00a0Andri \u00cdsak \u00de\u00f3rhallsson<\/p>\n

Heiti ritger\u00f0ar:<\/strong>\u00a0T\u00e6ringarheg\u00f0un efna \u00ed h\u00e1hita jar\u00f0hitaumhverfi (Corrosion Behaviour of Materials in High-Temperature Geothermal Environments)<\/p>\n

Andm\u00e6lendur:<\/strong>
<\/strong>Dr. Richard Barker, d\u00f3sent vi\u00f0 University of Leeds, Bretlandi
Dr. Marc Singer, d\u00f3sent vi\u00f0 University of Ohio, Bandar\u00edkjunum<\/p>\n

Lei\u00f0beinandi:<\/strong>\u00a0Dr. Sigr\u00fan Nanna Karlsd\u00f3ttir, pr\u00f3fessor vi\u00f0 I\u00f0na\u00f0arverkfr\u00e6\u00f0i-, v\u00e9laverkfr\u00e6\u00f0i- og t\u00f6lvunarfr\u00e6\u00f0ideild H\u00cd<\/p>\n

Einnig \u00ed doktorsnefnd:<\/strong>
<\/strong>Dr. Andri Stef\u00e1nsson, pr\u00f3fessor vi\u00f0 Jar\u00f0v\u00edsindadeild H\u00cd
Dr. Christiaan Petrus Richter, pr\u00f3fessor vi\u00f0 I\u00f0na\u00f0arverkfr\u00e6\u00f0i-, v\u00e9laverkfr\u00e6\u00f0i- og t\u00f6lvunarfr\u00e6\u00f0ideild H\u00cd<\/p>\n

Doktorsv\u00f6rn st\u00fdrir:<\/strong>\u00a0Dr. R\u00fanar Unn\u00fe\u00f3rsson, pr\u00f3fessor og deildarforseti I\u00f0na\u00f0arverkfr\u00e6\u00f0i-, v\u00e9laverkfr\u00e6\u00f0i- og t\u00f6lvunarfr\u00e6\u00f0ideildar H\u00cd<\/p>\n

\u00c1grip<\/strong><\/p>\n

Jar\u00f0hitaorkun\u00fdtni v\u00f6kva me\u00f0 h\u00e1a entalp\u00edu (vermi) er ein af m\u00f6rgum a\u00f0fer\u00f0um sem h\u00e6gt er a\u00f0 nota til a\u00f0 stu\u00f0la a\u00f0 umhverfisv\u00e6nni og sj\u00e1lfb\u00e6rri orkunotkun \u00ed framt\u00ed\u00f0inni. Til a\u00f0 gera \u00feessa tegund orkun\u00fdtni ar\u00f0b\u00e6ra \u00fearf hins vegar a\u00f0 yfirvinna nokkrar t\u00e6knilegar hindranir, \u00fe.m.t. r\u00e9tt val \u00e1 hr\u00e1efnum sem hefur gott t\u00e6ringar\u00feol \u00ed jar\u00f0hitaf\u00f3\u00f0ringar og b\u00fana\u00f0i fyrir jar\u00f0hitaorkuver. \u00deessi doktorsritger\u00f0 fjallar um ranns\u00f3kn \u00e1 t\u00e6ringarheg\u00f0un svarts st\u00e1ls og annarra t\u00e6ringar\u00feolinna melma \u00ed hermdum jar\u00f0hitav\u00f6kva vi\u00f0 h\u00e1 hitastig. T\u00e6ringarpr\u00f3fanir \u00e1 m\u00e1lm- og melmiss\u00fdnum (svart st\u00e1l, ry\u00f0fr\u00ed st\u00e1l, nikkel melmi og t\u00edtanium melmi) voru framkv\u00e6mdar \u00ed yfirhita\u00f0ri gufu me\u00f0 H2S, CO2 og HCl vi\u00f0 350 \u00b0C og 10 b\u00f6rG. Nokkur s\u00fdnanna voru einnig pr\u00f3fu\u00f0 eftir a\u00f0 k\u00edsilox\u00ed\u00f0 (SiO2) haf\u00f0i veri\u00f0 \u00fatfellt \u00e1 s\u00fdnin. Einnig voru s\u00fdni pr\u00f3fu\u00f0 vi\u00f0 su\u00f0u og \u00fe\u00e9ttingu \u00e1 hermdum jar\u00f0hitav\u00f6kva vi\u00f0 10 b\u00f6rG og vi\u00f0 l\u00e6gri hitastig en 350\u00b0C. Svart st\u00e1l og h\u00e1entr\u00f3p\u00edumelmi me\u00f0 kopar (Cu) t\u00e6r\u00f0ust greinilega en a\u00f0rir t\u00e6ringar\u00feolnir m\u00e1lmar t\u00e6r\u00f0ust ekki. Ennfremur var\u00f0 t\u00e6ringarska\u00f0i \u00ed sv\u00f6rtu st\u00e1li meiri vi\u00f0 su\u00f0u og \u00fe\u00e9ttingu \u00e1 jar\u00f0hitav\u00f6kvanum en \u00ed yfirhitu\u00f0um v\u00f6kva sem s\u00fdnir a\u00f0 t\u00e6ringarheg\u00f0un st\u00e1lsins er h\u00e1\u00f0 \u00e1standi og hitastigi t\u00e6ringarv\u00f6kvans. T\u00e6ringarskemmdir \u00e1 h\u00e1entr\u00f3p\u00edumelmum sem innih\u00e9ldu kopar jukust me\u00f0 meira koparinnihaldi melmisins \u00ed t\u00e6ringarpr\u00f3funum \u00ed yfirhitu\u00f0um v\u00f6kva. Auknar t\u00e6ringarskemmdir er h\u00e6gt a\u00f0 \u00fatsk\u00fdra me\u00f0 auknum styrk \u00e1 koparr\u00edkum f\u00f6sum \u00ed h\u00e1entr\u00f3p\u00edumelminu. T\u00e6ringarhra\u00f0i var metinn me\u00f0 vigtartapi og var l\u00e6gri en 0,1 mm\/\u00e1r fyrir \u00f6ll s\u00fdnin sem voru pr\u00f3fu\u00f0 \u00ed yfirhitu\u00f0um v\u00f6kva. Uppbygging og myndgreining efnis og t\u00e6ringarleifa var greind \u00ed rafeindasm\u00e1sj\u00e1 (SEM) og efnasamsetning \u00feeirra var greind \u00ed XEDS greini og r\u00f6ntgengreini (XRD). Ni\u00f0urst\u00f6\u00f0urnar s\u00fdna a\u00f0 t\u00e6ringar\u00feolin melmi ver\u00f0a ekki fyrir t\u00e6ringu \u00ed yfirhitu\u00f0um hermdum jar\u00f0hitav\u00f6kvanum. \u00deessi melmi \u00e6tti \u00fev\u00ed a\u00f0 velja frekar en svart st\u00e1l e\u00f0a h\u00e1entr\u00f3p\u00edumelmi sem innihalda kopar \u00ed jar\u00f0hitaumhverfi me\u00f0 yfirhitu\u00f0um v\u00f6kva.<\/p>\n

Um doktorsefni\u00f0<\/strong><\/p>\n

Andri \u00cdsak \u00de\u00f3rhallsson f\u00e6ddist 1980 og lauk B.Sc.-n\u00e1mi \u00ed efnaverkfr\u00e6\u00f0i fr\u00e1 H\u00e1sk\u00f3la \u00cdslands og s\u00ed\u00f0an \u00ed kj\u00f6lfari\u00f0 M.Sc.-n\u00e1mi \u00ed efnaverkfr\u00e6\u00f0i fr\u00e1 KTH \u00ed Sv\u00ed\u00fej\u00f3\u00f0. Eftir meistaran\u00e1mi\u00f0 vann Andri sem verkfr\u00e6\u00f0ingur og stj\u00f3rnandi \u00ed \u00e1lframlei\u00f0sluverksmi\u00f0jum en h\u00f3f svo doktorsn\u00e1m \u00e1ri\u00f0 2016. Andri starfar n\u00fa sem framlei\u00f0slustj\u00f3ri hj\u00e1 M\u00e1lningu hf. Andri er giftur Ragnhei\u00f0i Gu\u00f0mundsd\u00f3ttur og saman eiga \u00feau \u00ferj\u00fa b\u00f6rn.
<\/strong><\/p>\n<\/div><\/div>","protected":false},"featured_media":5115,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2022-05-11T14:00:00+00:00","_phd_date_end":"2022-05-11T16:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0arsalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"T\u00e6ringarheg\u00f0un efna \u00ed h\u00e1hita jar\u00f0hitaumhverfi (Corrosion Behaviour of Materials in High-Temperature Geothermal Environments)","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_velaverkfraedi_andri_isak_thorhallsson","_phd_source_node_id":"383771","_phd_source_type":"vidburdir","_phd_member_id":794,"footnotes":""},"phd_school":[108,93],"phd_discipline":[110],"class_list":["post-6265","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-idnadarverkfraedi-velaverkfraedi-og-tolvunarfraedideild","phd_school-verkfraedi-og-natturuvisindasvid","phd_discipline-phd-i-velaverkfraedi"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6265","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6265\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/5115"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6265"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6265"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6265"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}