麻田散體系不銹鋼之真空熱處理研究

A Study in Vacuum Heat Treatment of Martensitic Stainless Steels

李勁宏(Jin-Hung Lee)

指導教授 ： 邱六合

大同大學/工程學院/材料工程學系所/碩士(2010年)

摘要

本研究在探討麻田散體系不銹鋼經淬火、回火真空熱處理及電漿氮化處理之微觀結構、耐蝕性和磨耗特性變化，選擇JIS SUS 420J2，ASSAB STAVAX ESR麻田散鐵系不鏽鋼作為研究材料。實驗試片使用真空爐在1000℃~1050℃持溫25分鐘後，進行3kg/cm2 N2氣淬、並於250℃~560℃的溫度進行回火，部份回火試片進行電漿氮化製程。結構分析包含OM、XRD、SEM等，並進行極化曲線及磨耗測試等量測。研究結果顯示，1020℃持溫25min後以N2氣淬，SUS420J2和STAVAX ESR硬度可達到53.7±0.1HRC和52.7±0.1HRC。並對480℃回火(硬度50.5±0.5HRC和52.3±0.5HRC)進行電漿氮化，經過活性網罩電漿氮化(Active Screen Plasma Nitriding )處理過的兩種材料表層硬度皆可提升到1200HV~ 1400HV，此塊材對輥輪經24000轉後，氮化SUS 420 J2和STAVAX ESR試片質量損失量分別為10mg和9.5mg，比起未氮化的480℃回火的試片(質量損失量分別為14.6mg和13.6mg)各降低約32 %和30 %，表示均可提升其耐磨耗的性能。由極化曲線試驗得知，在此溫度氮化後的試片均能保持原試片之優異耐蝕性，不至於因電漿氮化處理而導致耐蝕性下降。

關鍵字

麻田散體不銹鋼 ； 真空熱處理 ； 電漿氮化 ； 磨耗 ； 極化曲線

並列摘要

In this study two martensitic stainless steels, JIS SUS 420 J2 and ASSAB STAVAX ESR have been conducted at austenitizing temperature, 1000°C~1050°C, and tempering temperature ranging from 250℃ to 600℃ and active screen plasma nitriding (ASPN) treatment to observe the change of microstructure, corrosion and wear properties. Some specimens were austenitized at 1020°C, and temper temperature at 480℃, and then plasma nitrided at 420℃for 10 hours. The surface hardness of plasma nitrided specimen was raised to 1200~1400HV. The wear test was conducted at a load of 95.9 N with 200 rpm by using a block-on-roller wear testing machine. From the results of 24000 revolutions wear test, the mass loss of JIS SUS 420 J2 and ASSAB STAVAX ESR are 10 mg and 9.5 mg respectively. The mass losses of nitrided specimens were reduced by 32% and 30 % with respective to the unnitrided specimens. Therefore, the active screen plasma nitriding (ASPN) treatment at 420℃for 10 hours can improve the surface hardness, wear resistance and corrosion resistance of the martensitic stainless steels.

並列關鍵字

martensitic stainless steel ； wear test ； polarization test ； vacuum heat treatment ； plasma nitriding

參考文獻

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