کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
831073 1470363 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of component’s geometry on the plasma nitriding behavior of AISI 4340 steel
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی (عمومی)
پیش نمایش صفحه اول مقاله
Effect of component’s geometry on the plasma nitriding behavior of AISI 4340 steel
چکیده انگلیسی

The main aim of this work was to investigate the effect of the sample geometry on properties of the conventional plasma nitrided (CPN) and active screen plasma nitrided (ASPN) steel. Sample assemblies consisting of rectangular grooved steel blocks with different groove dimensions of 2, 4, 6, 8 and 10 (W) × 40 (H) × 20 (L) mm3 and AISI 4340 steel plates (substrates) with dimensions of 10 × 40 × 60 mm3, to serve as groove cover, were prepared. The sample assemblies were conventional and active screen plasma nitrided under the gas mixture of 75%N2 + 25%H2, at temperatures of 500 °C and 540 °C, pressure of 4 torr, for 5 h. Properties of the nitrided substrates were investigated by evaluating compound layer thickness, case depth, phase composition and hardness profile. Results of the experiments showed that the thickness of the compound layer, hardness and nitrided case depth increased with increasing the width of the groove for both methods. Also, in each sample, nitrogen atoms penetrated more deeply in the regions of the groove closer to the edge. Hallow cathode effect occurred at the sample with 2 mm width groove, in the CPN method, leading to the overheating of the sample. In ASPN, the hardness and the nitrided case depth are lower in comparison with CPN. The surface morphology of the CPN treated samples consists of cauliflower shape surface nitrides while the surface of the AS plasma nitrided samples are covered by the hexagonal particles with uniform distribution.


► The thickness of the compound layer increases with increasing in temperature and groove width.
► Surface layer at the remote regions from the edge is thinner than that of closer regions.
► The hardness and the case depth of the nitrided layer increase with increasing the width of the groove.
► Intensity of ε phase increases with increasing the width of the groove in both methods.
► The ASPN specimens are covered by hexagonal particles and for the CPN by cauliflower shape nitrides.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials & Design - Volume 34, February 2012, Pages 516–521
نویسندگان
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