diplomsko delo
Abstract
Namen diplomskega dela je karakterizacija mikrostrukture in mehanskih lastnosti nerjavnih jekel 08X14NDL in GX4CrNi13-4. Karakterizacija mehanskih lastnosti je potekala s pomočjo nateznega preizkusa, merjenja trdote in udarne žilavosti, karakterizacija mikrostrukture pa s pomočjo svetlobne mikroskopije, rentgenske fazne analize (XRD), vrstične elektronske mikroskopije (SEM), energijsko disperzijske spektroskopije (EDS) in izračunov ravnotežnih faznih diagramov za preiskovana jekla.
Mikrostruktura jekel 08X14NDL in GX4CrNi13-4 je sestavljena pretežno iz popuščenega martenzita in δ-ferita. Delež δ-ferita se med toplotno obdelavo ne spreminja in znaša 18,7 % za jeklo 08X14NDL in 2,6 % za jeklo GX4CrNi13-4. S pomočjo mikrokemijske analize EDS je bilo ugotovljeno, da δ-ferit v obeh jeklih vsebuje predvsem večji delež kroma in manjši delež niklja kakor martenzit. Mehanske lastnosti jekla GX4CrNi13-4 so dosegale zahteve standarda, pri jeklu 08X14NDL pa so bile trdote prenizke glede na zahteve standarda. Mikrotrdota δ-ferita je bistveno manjša od mikrotrdote martenzita. Z ustrezno kemično sestavo bi v jeklu 08X14NDL lahko zmanjšali delež mehkejšega δ-ferita.
Keywords
mehanske lastnosti;mikrostruktura;martenzitna nerjavna jekla;08X14NDL;GX4CrNi13-4;delta;-ferit;
Data
Language: |
Slovenian |
Year of publishing: |
2018 |
Typology: |
2.11 - Undergraduate Thesis |
Organization: |
UL NTF - Faculty of Natural Sciences and Engineering |
Publisher: |
[A. Bajželj] |
UDC: |
669 |
COBISS: |
1778527
|
Views: |
989 |
Downloads: |
318 |
Average score: |
0 (0 votes) |
Metadata: |
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Other data
Secondary language: |
English |
Secondary title: |
mechanical properties and microstructure of martensitic stainless steels 08X14NDL and GX4CrNi13-4 |
Secondary abstract: |
The main purpose of the diploma work was characterization of microstructure and mechanical properties of 08X14NDL and GX4CrNi13-4 martensitic stainless steels. Mechanical properties were characterized by tensile testing, hardness testing and impact toughness testing. Microstructure was characterized by using light microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and calculation of equilibrium phase diagrams.
Microstructure of 08X14NDL and GX4CrNi13-4 steels is composed of martensite and δ-ferrite. The volume fraction of δ-ferrite is 18.7 % for the 08X14NDL steel and 2.6 % for the GX4CrNi13-4 steel and does not change markedly during the process of the heat treatment. EDS microanalysis shows that δ-ferrite in both alloys contains more chromium and less nickel than the martensite. The mechanical properties of the GX4CrNi13-4 steel have met the requirements of the standard while in the case of the 08X14NDL steel the hardness was lower than required. Microhardness of δ-ferrite is significantly lower than the microhardness of martensite. The content of δ-ferrite with lower hardness could be reduced by a proper chemical composition of the 08X14NDL steel. |
Secondary keywords: |
mechanical properties;microstructure;martensitic stainless steels;08X14NDL;GX4CrNi13-4;delta;-ferrite; |
Type (COBISS): |
Bachelor thesis/paper |
Study programme: |
0 |
Thesis comment: |
Univ. v Ljubljani, Naravoslovnotehniška fak. , Odd. za materiale in metalurgijo |
Pages: |
XI, 32 f. |
ID: |
10994942 |