Hårdfräsning i verktygsstål
Förslitning av skäregg
This thesis work is made by Torbjörn Johansson on Karlstad University for Uddeholms AB. The assignment in this thesis work was to investigate tough cutting in three different tool steels: Vanadis 4 Extra, Vancron 40 and Sverker 21. The research was to compare the wear of the tool after cutting in each one of the tool steel alloys. The research was also made to see if the tool cutting in Vancron 40 has a better wear than the tool cutting in Vanadis 4 Extra and also compare the results with Sverker 21. All three of these alloys are a part of Uddeholms AB:s range of products, and is used in applications like forming tools and knife tools. Vancron 40 is a powder steel with a very good combination of mechanical properties like ductility, adhesive strength and hardness. But it is difficult to cut, mill and manufacture Vancron 40, and it also has a high material cost. If it can be showed that Vancron 40 has a better ability when it comes to cutting compared with Vanadis 4 Extra it would lead to a good sales point because more savings for the customers can be made regarding their tools. The research is made in a ?Doosan VMD 600? 5-axis milling machine, the tools that have been used are from Sandvik Coromant and are a ball mill and a bull mill. Both mills have a diameter of 4 mm and they are both made of solid carbide. The result showed that Vancron 40 has a minor wear of tool compared to Vanadis 4 Extra and in most cases also Sverker 21. A cost example diagram was made where time against tooling-cost are presented. When the tool has cut (effective time) in about 950 hours the savings are about 800 000 SEK. Also a research about surface finish was made but the results were pretty confusing and no pattern was found. Therefore no conclusions were made regarding surface finish.