 |
Visits: 86111532
AMS now reading: 1
|
|
|
|
|
 |
|
|
| Visuttipitukul P., Paa-rai C., Kuwahara H. |
| CHARACTERIZATION OF PLASMA NITRIDED AISI H13 TOOL STEEL |
Abstract
The purpose of this study was to characterize surface of plasma nitrided AISI H13 tool steels. H13 tool steel specimens were plasma nitrided at 773 and 823 K for 36 and 72 ks. All samples were characterized by optical microscope, GIXD at the incident angle of 1 and 5 degree, XRD, EDS, EPMA and Vicker’s microhardness testing. The results suggest that nitriding time and temperature affect on layer depth. Thickness of nitriding layer increases with increasing either nitriding time or nitriding temperature. Growth rate of nitriding layer can be increased by increasing nitriding temperature as can be seen from the results. The growth rates of nitriding layer are about 0.69 ?m/s0.5 and 0.45 ?m/s0.5 when nitriding temperatures are 823 K and 773 K, respectively. Microstructures of nitriding layers in H13 tool steels are dark gray in color which is typical microstructure of nitrided steel by other nitriding methods. However, there is no white in this nitriding layer even when the nitriding layer is thicker than 200 ?m. GIXD and XRD profiles show that the nitriding layers of all specimens consist of Fe4N, Fe3N and CrN compound. Carbide and nitride precipitates can be seen in the microstructures taken by SEM and EPMA. Qualitative studies of nitriding layer by EDS and EPMA show the coexistence of chromium carbide and chromium nitride in the nitriding layer. This result shows that most of chromium nitride precipitates along the existing chromium carbide in martensite matrix. Hardness of nitriding H13 steel is remarkable increased up to 1300 HV at the surface. The hardness increase is due to the formation of carbide and nitride precipitates in martensite matrix.
|
| Keywords: Plasma nitriding|H13 steel|Chromium nitride|Precipitate| |
| No 3 (2006), p. 264-274 |
|
|
|
|
|
|
|
Editors and press
AMS online
