Filters
cris logo
-
New search Filters
Select from list
Displayed from Show more
You have reached the maximum number of displayed search results.
All results displayed
No results are available for the search performed
Displayed from
You have reached the maximum number of displayed search results.
All results displayed
Loading results
Obtaining statistical data

Projects / Programmes source: ARIS

Adaptable hardening of austenitic steel surfaces by cryogenic forming processes

Edit
Research activity

Code Science Field Subfield
2.10.02  Engineering sciences and technologies  Manufacturing technologies and systems  Manufacturing technology 

Code Science Field
2.03  Engineering and Technology  Mechanical engineering 
Keywords
cryogenic forming, austenitic stainless steel, structural steel transformation, austenite, martensite, strain rate, tensile test, process modeling, numerical simulations, bar drawing, controlled local specimen subcooling, digital valves, flexible forming system
Evaluation (rules)
source: COBISS
Evaluation of bibliographic research performance indicators according to ARIS methodology
Citations Citations for bibliographic records in COBIB.SI that are linked to records in citation databases
source: WoS source: Scopus source: COBISS
Researchers (20)
no. Code Name and surname Research area Role Period No. of publications
1.  10762  MSc Boštjan Arh  Materials science and technology  Researcher  2020 - 2023  0 
2.  38468  Pavel Drešar    Technical associate  2020  0 
3.  10499  PhD Niko Herakovič  Mechanical design  Researcher  2020 - 2023  0 
4.  33239  PhD Marko Jerman  Manufacturing technologies and systems  Researcher  2020 - 2023  0 
5.  53789  PhD Matic Jovičević Klug  Materials science and technology  Researcher  2021  0 
6.  31395  PhD Fevzi Kafexhiu  Materials science and technology  Researcher  2020  0 
7.  27758  Andrej Kos  Manufacturing technologies and systems  Researcher  2020  0 
8.  12260  PhD Andrej Lebar  Manufacturing technologies and systems  Researcher  2020 - 2023  0 
9.  39193  PhD Jure Murovec  Energy engineering  Researcher  2023  0 
10.  23469  PhD Henri Orbanić  Manufacturing technologies and systems  Researcher  2020  0 
11.  12957  PhD Tomaž Pepelnjak  Manufacturing technologies and systems  Head  2020 - 2023  0 
12.  15269  PhD Bojan Podgornik  Materials science and technology  Researcher  2020 - 2023  0 
13.  50842  Jernej Protner  Manufacturing technologies and systems  Researcher  2020 - 2021  0 
14.  39494  PhD Matevž Resman  Manufacturing technologies and systems  Researcher  2020 - 2023  0 
15.  17999  Matjaž Rot    Technical associate  2020 - 2021  0 
16.  30912  PhD Izidor Sabotin  Manufacturing technologies and systems  Researcher  2020 - 2023  0 
17.  51435  Luka Sevšek  Manufacturing technologies and systems  Researcher  2020 - 2023  0 
18.  31322  PhD Marko Šimic  Manufacturing technologies and systems  Researcher  2020 - 2023  0 
19.  18553  PhD Joško Valentinčič  Manufacturing technologies and systems  Researcher  2020 - 2023  0 
20.  37172  PhD Hugo Zupan  Manufacturing technologies and systems  Researcher  2020 - 2023  0 
Organisations (2)
no. Code Research organisation City Registration number No. of publications
1.  0782  University of Ljubljana, Faculty of Mechanical Engineering  Ljubljana  1627031  0 
2.  0206  Institute of Metals and Technology  Ljubljana  5051622000  0 
Abstract
Austenitic stainless steel products represent an important segment of technological solutions for working at high and low temperatures and in corrosive environments. The surfaces of these steels cannot be hardened under normal technological conditions, although some products require a tough product and a hard (martensite) surface at the same time. Despite the enormous potential of this type of solution, there are no known solutions worldwide, and even applications in which the entire austenitic workpiece is transformed into a martensitic structure with cryogenic heat treatment are rare. The transformation of austenitic steels into a martensitic structure can be achieved much faster than by the cryogenic heat treatment by the cryogenic forming. The metallurgical fundamentals underlying these processes are incompletely researched and with models only poorly described in the literature. The project will carry out fundamental research on cryogenic forming with the aim of bringing the technology to a level that allows the gradation of the material from the hard outer layer (martensite) to the tough core (austenite) to be controlled. The main objective of the project is the establishment of fundamental knowledge which enables a flexible cryogenic cooling. This enables under the appropriate forming conditions the production of the mentioned gradation and the partial phase change of the cross-section to the desired depth. For this purpose, the effects of temperature, cooling rate, size of plastic strain, and strain rate on martensite formation and the thickness of the resulting layer are first investigated by simple methods of cryogenic soaking and simple cryogenic pouring of the sample with liquid nitrogen. At the same time, an adaptive cooling system is being developed which supplies the optimum amount of cryogenic medium to the cooling area of the workpiece via digital valves. In addition to digital valve technology, the complete cooling system will offer suitable nozzle designs with temperature sensors and a safety chamber for phase separation of liquid and vaporized nitrogen. It is very difficult to perform continuous workpiece temperature measurement during the forming process. Therefore, a numerical model for the calculation of the temperature field in the workpiece both during cooling by soaking in cryogenic medium and during liquid nitrogen pouring will be set-up and experimentally verified. A measuring system is being developed to analyse the temperatures at different points on the workpiece as a function of the ambient temperature during the cryogenic forming. Since the strain affects the temperature field, we will also set up a numerical model of the forming and take into account the calculated heat generated by the work hardening during the forming. An important contribution of the project is the definition of a new understanding of cryogenic forming technology and the key parameters influencing it. Understanding the effects also allows a scientific approach to identify the fundamental phenomena that lead to the onset of phase transformation of austenitic steel when plastic strain is introduced into the material. Only a good understanding of the fundamental phenomena enables the creation of models that form the basis for numerical evaluations for the qualitative prediction of forming processes in a cryogenic environment. The modelling of the cryogenic forming is a new field which has not yet been explored in the scientific literature. We will model uniaxial tensile and compression tests as well as bar drawing and verify these tests experimentally. The material description identified by experiments forms the basis for forming modelling, whereby structural changes in the cryogenic state are taken into account. The above-mentioned basic research and the understanding of the fundamental phenomena in the material during the cryogenic forming ensure the quality implementation of the applied projects in the continuation of this
Confirmation required
Views history
Favourite