 |
Visits: 85974580
AMS now reading: 1
|
|
|
|
|
 |
|
|
| Straka Ľ., Čorný I. |
| HEAT TREATING OF CHROME TOOL STEEL BEFORE ELECTROEROSION CUTTING WITH BRASS ELECTRODE |
Abstract
The paper deals with heat treating of material assigned for shearing tools production by progressive electroerosion method of machining. The main aim of the contribution is to describe in detail the procedure of heat treatment of tool-steel blocks made from steel EN ISO 9676 X210Cr12 (STN 19 436) including processes taking place inside basic material. Because of its favourable mechanical properties, tool steel EN ISO 9676 X210Cr12 (STN 19 436) belongs to materials most used for shearing tools production. It is a chrome steel with high wear-resistance, and resistance to dimension variations at high temperatures. Since the given material is of high strength, demanding machining conditions are to be expected too. Effective, and at the same time the most used method for production from this steel appears to be electroerosion machining which ensures high quality and machining precision. ?1,2? In certain cases, it is the only method that enables production of complicated internal shapes of shearing tools and keeping of high cut contour precision. In addition, this method does not impose any restrictions concerning material strength, because material removal is carried out by electric discharge, and not by mechanical impact of cutting tool, as it is usual at conventional machining. To satisfy all the quality requirements on shearing tools, it is necessary to apply heat treatment on semiproduct before actual machining process. Unsuitable or low-quality heat treating has significant impact not only on resultant quality and precision of shearing tool, but, above all, on its operating life. Proposed procedure was realized on experimental steel block in particular conditions of company that produces shearing tools. Results of the experiment were verified from the view point of achieved resultant hardness quality of basic material after martensitic quenching and 2-phase tempering in vacuum furnace, applying Rockwell method. The paper also presents possible causes of semiproduct quality insufficiencies including heat treating defects, and gives recommendations for preventing of production wasters.
|
| Keywords: Electroerosion Machining|Quenching|Tempering|Heat Treating|Hardness of Surface|Wire Electrical Discharge Machining (WEDM)| |
| No 3 (2009), p. 180-186 |
|
|
|
|
|
|
|
Editors and press
AMS online
