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4. 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, original scientific article Abstract: 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. Keywords: martensitic stainless steel, deep cryogenic treatment, hydrogen embrittlement, slow strain rate tensile test Published in DiRROS: 23.05.2024; Views: 122; Downloads: 134 Full text (17,73 MB) This document has many files! More... |
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6. Giant solitary fibrous tumour of the pleura : case report and review of the literatureAnton Crnjac, Bojan Veingerl, Damjan Vidovič, Rajko Kavalar, Aljaž Hojski, 2015, review article Abstract: Background. Solitary fibrous tumours of the pleura (SFTP) are rare tumours. They are mostly benign. Only around 12% of them are malignant. In the initial stage they are mostly asymptomatic and by growing they cause chest pain, irritating cough and dyspnoea on account of the pressure created on the surrounding structures. Rare giant tumours have compression symptoms on the mediastinal structures. The condition requires tiered diagnostic radiology. Preoperative biopsy is not successful in most cases. The therapy of choice is radical surgical tumour removal. Malignant or nonradically removed benign solitary fibrous tumours of the pleura additionally require neoadjuvant therapy. Case report. A 68-year old patient was hospitalized for giant solitary fibrous tumour of the pleura in the right pleural cavity. With its expansive growth the tumour caused the shift of the mediastinum by compressing the lower vena cava, right cardiac auricle as well as the intermediate and lower lobe bronchus. Due to cardiac inflow obstruction and right lung collapse, the patient's life was endangered with signs of cardio-respiratory failure. After preoperative diagnostic radiology, the tumour was surgically removed. Postoperatively, the patient's condition improved. No disease recurrence was diagnosed after a year. Conclusions. Giant solitary fibrous tumour of the pleura may cause serious and life-threatening conditions by causing compression of the pleural cavity with its expansive growth. Early diagnosis of the condition enables less aggressive as well as video-assisted thoracic surgery in patients with significantly better state of health. Large tumour surgeries in cardio-respiratory affected patients are highly risk-associated procedures. Published in DiRROS: 23.04.2024; Views: 289; Downloads: 221 Full text (2,16 MB) This document has many files! More... |
7. The influence of cytokine gene polymorphisms on the risk of developing gastric cancer in patients with Helicobacter pylori infectionDavid Štubljar, Samo Jeverica, Tomislav Jukić, Miha Skvarč, Tadeja Pintar, Bojan Tepeš, Rajko Kavalar, Borut Štabuc, Alojz Ihan, 2015, original scientific article Keywords: cytokine gene, gastric cancer, Helicobacter pylori infection Published in DiRROS: 16.04.2024; Views: 199; Downloads: 41 Full text (587,90 KB) |
8. Identification of three anatomical patterns of the spinal accessory nerve in the neck by neurophysiological mappingBoštjan Lanišnik, Miha Žargi, Zoran Rodi, 2014, original scientific article Abstract: Background. In spite of preservation of the accessory nerve there is still considerable proportion of patients with partial nerve damage during modified radical neck dissection (MRND). Methods. The nerve was identified during the surgery and its branches for the trapezius muscle mapped with nerve monitor. Results. The accessory nerve was mapped during 74 hemineck dissections and three patterns were identified. In type 1 nerve exits at the posterior end of the sternocleidomastoid muscle (SCm) and then it enters the level V (66 %). In type 2 the nerve for trapezius muscle branches off before entering the SCm (22 %). In type 3 the nerve exits at the posterior part of the SCm and it joins to the cervical plexus (12 %). The nerve than exits this junction more medially as a single trapezius branch. Conclusions. The description of three anatomical patterns in level II and V could help preserving the trapezius branch during MRND. Keywords: spinal accessory nerve, nerve mapping, neck dissection, anatomy, shoulder disability Published in DiRROS: 11.04.2024; Views: 478; Downloads: 330 Full text (1,66 MB) This document has many files! More... |
9. Sliding wear behaviour of conventional and cryotreated PM Cr-V (Vanadis 6) ledeburitic tool steelVenu Yarasu, Peter Jurči, Peter Gogola, Bojan Podgornik, Marko Sedlaček, 2023, original scientific article Keywords: cold work tool steel, conventional treatment, cryogenic treatment, hardness, reciprocal sliding, wear Published in DiRROS: 08.04.2024; Views: 254; Downloads: 38 Full text (7,85 MB) This document has many files! More... |
10. Life cycle assessment of metal alloys for structural applicationsKatja Malovrh Rebec, Boštjan Markoli, Blaž Leskovar, 2018, published scientific conference contribution (invited lecture) Abstract: The study compared environmental footprints of two types of Al-alloys: well-known 5083 aluminium alloy with magnesium and traces of manganese and chromium in its composition. This material is highly resistant to seawater corrosion and the influence of industrial chemicals. Furthermore, it retains exceptional strength after welding. The comparisons were made to an innovative alloy where the aluminium based matrix is reinforced by metastable quasicrystals (QC), thus avoiding magnesium in its composition. Furthermore, we checked other aluminium ingots' footprints and compared European average and Germany country specific production data. Environmental footprints were assessed via cradle to gate life cycle assessment. Our findings normalized to 1 m2 plate suggest, that newly proposed alloy could save around 50 % in value of parameters abiotic resources depletion of fossil fuels, acidification, eutrophication, global warming potential and photochemical ozone creation potential if we compare Qc5 to 6 mm 5083 alloy plate. Only abiotic resources depletion of elements and ozone depletion parameters increase for Qc5 compared to 6 mm 5083 alloy plate. Keywords: environmental footprints, LCA, Al-alloys Published in DiRROS: 05.04.2024; Views: 188; Downloads: 93 Full text (2,29 MB) This document has many files! More... |