플라즈마 질화법에 의한 SUS316L 스테인레스강의 표면경화에 관한 연구

Abstract

본 연구는 SUS316L 스테인레스강을 이용하여 500℃∼600℃의 온도범위에서 NH₃가스의 유량을 0.5∼2.1ℓ/min로 변화시키고, 20∼110분 동안 플라즈마 질화처리하여, 강 표면에 생성된 경화층의 두께와 경도 및 조직을 조사하였다.

반응온도 550℃, NH₃가스의 유량 2.1ℓ/min에서 110분 동안 질화 하였을 경우 생성된 질화층의 두께는 약57㎛로 최대치를 나타내었다.

그리고 질화처리 한 시편을 XRD 분석한 결과 생성된 질화층은 CrN＋r－Fe₄N＋Fe₃N으로 구성되어 있는 화합물층 이었으며, 확산층은 생성되지 않았고, 생성된 질화층의 경도의 최고치는 약 Hv 1800 이었다.

플라즈마 질화법에 의한 SUS316L 스테인레스 강의 표면경화의 최적조건은 550℃, 2.1ℓ/min. NH₃가스, 110분이었다.

A nitrided layer on SUS316L stainless steel by plasma nitrised for back ferrule in one parts of tube fitting has been studied.

Specimen was nitrided over 500℃ to 650℃ reaction temperature range with 0.5 to 2.1 ℓ/min. NH₃gas flow rate for 20 to 110 min.

The thickness of nitrided layer showed maximum value about 57㎛ at 550℃ reaction temperature and with 2.1ℓ/min. NH₃gas flow rate for 110 min.

The result of XRD, nitrided layer was mainly composed of CrN＋r－Fe₄N＋Fe₃N, but not detected diffusion layer.

And also, when NH₃gas flow rate 2.1ℓ/min. , the maximum hardness value of nitrided layer was revealed about Hv 1800 at 550-600℃ reaction temperature range.

In this study, the optimum condition of nitrided on SUS316L stainless steel was observed at 550℃ reaction temperature and 2.1ℓ/min. , NH₃gas flow rate for 110 min.

A nitrided layer on SUS316L stainless steel by plasma nitrised for back ferrule in one parts of tube fitting has been studied.

Specimen was nitrided over 500℃ to 650℃ reaction temperature range with 0.5 to 2.1 ℓ/min. NH₃gas flow rate for 20 to 110 min.

The thickness of nitrided layer showed maximum value about 57㎛ at 550℃ reaction temperature and with 2.1ℓ/min. NH₃gas flow rate for 110 min.

The result of XRD, nitrided layer was mainly composed of CrN＋r－Fe₄N＋Fe₃N, but not detected diffusion layer.

And also, when NH₃gas flow rate 2.1ℓ/min. , the maximum hardness value of nitrided layer was revealed about Hv 1800 at 550-600℃ reaction temperature range.

In this study, the optimum condition of nitrided on SUS316L stainless steel was observed at 550℃ reaction temperature and 2.1ℓ/min. , NH₃gas flow rate for 110 min.