Influence of primary precipitate shape, size volume fraction and distribution in PM tool steels on galling resistance
2015 (Engelska)Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hp
Studentuppsats (Examensarbete)Alternativ titel
Påverkan av primära karbiders storlek, volymfraktion och distribution i PM verktygsståls motstånd mot galling (Svenska)
Abstract [en]
In sheet metal forming (SMF), the major failure reason is galling. Galling is a process of different wear stages that leads to destruction of both the forming tool and the sheet metal working piece and is, because of that, of big economic importance for the SMF industries. Therefore, investigations and researches about how tool steels microstructure affect the tool steels galling resistance is of high priority. In the present work, different carbide properties were studied to find out how their properties affected the tool materials galling resistance. The investigated carbide properties were:
- Shape and size of the carbides
- Carbide volume fraction
- Carbide distribution in the microstructure
The investigation included three tools, all made of the PM tool steel S390, that were heattreated differently in order to achieve different carbide properties but still maintain the same hardness. The tools were galling tested in a slider-on-flat-surface (SOFS) tribometer to determine their galling resistances. In a scanning surface electron microscope (SEM) the tools galling marks were analyzed to find explanations for the SOFS tribometer results and the connection to the tools different carbide properties.
The investigations most galling resistant tool was the tool that had the microstructure with largest carbides which were distributed at grain boundaries and the second highest carbide volume fraction among the investigated tools.
Ort, förlag, år, upplaga, sidor
2015. , s. 31
Nyckelord [en]
Carbide, sheet metal forming, slider on flat surface tribometer
Nationell ämneskategori
Naturvetenskap
Identifikatorer
URN: urn:nbn:se:kau:diva-37813OAI: oai:DiVA.org:kau-37813DiVA, id: diva2:850323
Ämne / kurs
Maskinteknik & Materialteknik
Utbildningsprogram
Civilingenjör: Maskinteknik (300 hp)
Handledare
Examinatorer
2015-09-012015-09-012015-09-01Bibliografiskt granskad