1. Susceptibility of X17CrNi16-2 martensitic stainless steel to hydrogen embrittlement after conventional and deep cryogenic heat treatmentMirjam Bajt Leban, Bojan Zajec, Bojan Podgornik, Črtomir Donik, Patricia Jovičević Klug, Miha Hren, Andraž Legat, 2024, izvirni znanstveni članek Povzetek: A low carbon/ high chromium martensitic stainless steel, X17CrNi16-2, was heat treated using two different hardening and tempering regimes (1050 ◦ C/480 ◦ C or 980 ◦C/600 ◦C) — promoting either a high strength or high toughness state, respectively and further combined with deep cryogenic treatment (DCT) at 196 ◦C for 24 h. Over recent years DCT has been recognized as a promising technique to improve the properties of steel, predominantly with respect to its tensile strength, toughness and wear resistance. The influence of DCT on the hydrogen embrittlement resistance of martensitic stainless steel has not yet, however, been reported.
A slow strain rate tensile test (SSRT) with simultaneous cathodic hydrogen charging was selected as the method to assess potential susceptibility to hydrogen embrittlement (HE). Relatively low-intensity hydrogen charging, utilizing a constant current density of 0.1 mA/cm2, in a non-corrosive, slightly alkaline buffer solution, led to a clear reduction in the ultimate tensile stress. This reduction, and therefore the HE susceptibility, was more pronounced in the steel with a higher strength (i.e. that subject to the 1050 ◦C/ 480 ◦C heat treatment condition). Furthermore, DCT did not appear to have any impact on the steel’s mechanical properties in the presence of hydrogen. Fractographic analysis showed clear evidence of HE in the hydrogen-charged specimens.
This paper presents results of the SSRT tests and further fractography results, and discusses the impact of conventional and deep cryogenic treatment on HE susceptibility. Ključne besede: martensitic stainless steel, deep cryogenic treatment, hydrogen embrittlement, slow strain rate tensile test Objavljeno v DiRROS: 23.05.2024; Ogledov: 260; Prenosov: 229 Celotno besedilo (17,73 MB) Gradivo ima več datotek! Več... |
2. Understanding carbide evolution and surface chemistry during deep cryogenic treatment in high-alloyed ferrous alloyPatricia Jovičević Klug, Levi Tegg, Matic Klug Jovičević, Rahul Parmar, Matteo Amati, Luca Gregoratti, László Almásy, Julie M. Cairney, Bojan Podgornik, 2023, izvirni znanstveni članek Ključne besede: cryogenic temperature, surface chemistry, microstructure, atom probe tomography (APT), scanning photoelectron microscopy (SPEM), small angle neutron scattering (SANS) Objavljeno v DiRROS: 08.03.2024; Ogledov: 390; Prenosov: 394 Celotno besedilo (20,08 MB) Gradivo ima več datotek! Več... |
3. Austenite reversion suppression with deep cryogenic treatment : a novel pathway towards 3rd generation advanced high-strength steelsPatricia Jovičević Klug, Matic Klug Jovičević, Lars Thormählen, Jeffrey McCord, Michael Rohwerder, Matjaž Godec, Bojan Podgornik, 2023, izvirni znanstveni članek Ključne besede: Martensitic stainless steel, deep cryogenic treatment, microstructure, mechanical properties, microstructural transformations, phase transformation Objavljeno v DiRROS: 02.02.2024; Ogledov: 346; Prenosov: 155 Celotno besedilo (13,70 MB) Gradivo ima več datotek! Več... |
4. Complex interdependency of microstructure, mechanical properties, fatigue resistance, and residual stress of austenitic stainless steels AISI 304LPatricia Jovičević Klug, Matic Klug Jovičević, Michael Rohwerder, Matjaž Godec, Bojan Podgornik, 2023, izvirni znanstveni članek Ključne besede: stainless steel, AISI 304L, deep cryogenic treatment (DCT), microstructure, mechanical properties, fatigue, residual stress Objavljeno v DiRROS: 02.02.2024; Ogledov: 403; Prenosov: 163 Celotno besedilo (5,90 MB) Gradivo ima več datotek! Več... |
5. Effect of deep cryogenic treatment on corrosion properties of various high-speed steelsJure Voglar, Živa Novak, Patricia Jovičević Klug, Bojan Podgornik, Tadeja Kosec, 2021, izvirni znanstveni članek Povzetek: The aim of the study was to evaluate the corrosion properties of three different grades of high-speed steel following a heat treatment procedure involving deep cryogenic treatment after quenching and to investigate how these properties are connected to the microstructure and hard- ness of the material. The hardness of steels was measured, and microstructural properties were determined through observation of the metallographically prepared steels using scanning electron microscopy. These studies were complemented corrosion evaluation by the use of corrosion potential measurement and linear polarization measurement of steels in a sodium tetraborate buffer at pH 10. The results showed that the deep cryogenic procedure of high-speed steel changed the microstructure and consequently affected the hardness of the investigated steels to different extents, depending on their chemical composition. Corrosion studies have confirmed that some high-speed steels have improved corrosion properties after deep cryogenic treatment. The most important improvement in corrosion resistance was observed for deep cryogenically treated high-speed steel EN 1.3395 (M3:2) by 31% when hardened to high hardness values and by 116% under lower hardness conditions. The test procedure for differentiating corrosion properties of differently heat-treated tool steels was established alongside the investigation. Ključne besede: deep cryogenic treatment, corrosion, microstructure, hardness Objavljeno v DiRROS: 01.08.2023; Ogledov: 466; Prenosov: 223 Celotno besedilo (5,82 MB) Gradivo ima več datotek! Več... |
6. Influence of the deep cryogenic treatment on AISI 52100 and AISI D3 steelʼs corrosion resistancePatricia Jovičević Klug, Tjaša Kranjec, Matic Klug Jovičević, Tadeja Kosec, Bojan Podgornik, 2021, izvirni znanstveni članek Povzetek: The effect of deep cryogenic treatment (DCT) on corrosion resistance of steels AISI 52100 and AISI D3 is investigated and compared with conventional heat-treated counterparts. DCTʼs influence on microstructural changes is subsequently correlated to the corrosion resistance. DCT is confirmed to reduce the formation of corrosion products on steelsʼ surface, retard the corrosion products development and propagation. DCT reduces surface cracking, which is considered to be related to modified residual stress state of the material. DCTʼs influence on each steel results from the altered microstructure and alloying element concentration that depends on steel matrix and type. This study presents DCT as an effective method for corrosion resistance alteration of steels. Ključne besede: steel, deep cryogenic treatment, corrosion, Raman, open access Objavljeno v DiRROS: 19.05.2023; Ogledov: 478; Prenosov: 322 Celotno besedilo (3,13 MB) Gradivo ima več datotek! Več... |
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8. Revealing the Pb whisker growth mechanism from Al-alloy surface and morphological dependency on material stress and growth environmentMatic Klug Jovičević, Tim Verbovšek, Patricia Jovičević Klug, Barbara Šetina, Bojan Ambrožič, Goran Dražić, Bojan Podgornik, 2022, izvirni znanstveni članek Ključne besede: aluminum alloy, metallic whiskers, residual stress, crystal growth, oxidation Objavljeno v DiRROS: 06.05.2022; Ogledov: 758; Prenosov: 251 Povezava na datoteko |
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10. Influence of deep cryogenic treatment on natural and artificial aging of Al-Mg-Si alloy EN AW 6026Matic Klug Jovičević, Rok Rezar, Patricia Jovičević Klug, Bojan Podgornik, 2022, izvirni znanstveni članek Ključne besede: aluminum alloy, microstructure, mechanical properties, precipitation, dispersoids, deep cryogenic treatment Objavljeno v DiRROS: 06.05.2022; Ogledov: 711; Prenosov: 281 Povezava na datoteko |