熱作工具鋼之固體滲氮研究

Abstract

本研究將JAC1熱作工具鋼施以不同條件(改變溫度、時間、粉末周圍的氣氛、處理方式、催滲劑CeO2添加量等)的固體粉末滲氮處理後，藉由顯微組織的觀察、表層硬度的量測、化學成分的分析及X-ray繞射實驗，研究固體粉末滲氮條件對滲氮效果的影響。實驗結果顯示，鋼料施以固體粉末滲氮時，改變滲氮粉末周圍的氣氛(空氣、氮氣、氧氣或真空)、處理方式(一次或兩次滲氮、一段或兩段滲氮)，對表層硬度和有效硬化深度沒有顯著的影響。而添加適當量的稀土元素之氧化物(CeO2)於滲氮粉末中，可顯著提高滲氮效果，在相同的滲氮溫度(540ºC)及時間(12小時)下，表層最高硬度可提升約24％，而有效硬化深度可增加60％。

In this research, solid powder nitriding treatments were applied on JAC1 hot work tool steel under different conditions (temperature, time, atmosphere surrounding the powder, nitriding method, supplement of catalyst CeO2, etc.). By observing the microstructure, measuring the hardness of the surface layer, analyzing chemical compositions and conducting X-ray diffraction experiments, the effects of solid nitriding conditions on the nitriding results of the steel were studied. Experimental results show that there were no significant effects on the hardness of the surface layer and effective hardening depth of the steel subjected to solid nitriding, with changing the atmosphere surrounding the powder (air, nitrogen, oxygen or vacuum) and treatment methods (nitriding once or twice, nitriding with one or two sections). Adding an appropriate amount of rare earth element oxide (CeO2) in nitriding powder could increase the nitriding effect significantly. Under the same nitriding temperature (540ºC) and time (12hr), the highest surface layer hardness could be promoted to approximately 24%, and the effective hardening depth could be increased to 60%.