KR100250220B1 - The plasma diffusion nitrizing for steel - Google Patents

The plasma diffusion nitrizing for steel Download PDF

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KR100250220B1
KR100250220B1 KR1019950047713A KR19950047713A KR100250220B1 KR 100250220 B1 KR100250220 B1 KR 100250220B1 KR 1019950047713 A KR1019950047713 A KR 1019950047713A KR 19950047713 A KR19950047713 A KR 19950047713A KR 100250220 B1 KR100250220 B1 KR 100250220B1
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diffusion
masking
steel
plasma
nitriding
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KR1019950047713A
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KR970043266A (en
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박정렬
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이구택
포항종합제철주식회사
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/04—Treatment of selected surface areas, e.g. using masks
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/24—Nitriding
    • C23C8/26—Nitriding of ferrous surfaces
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/36—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases using ionised gases, e.g. ionitriding
    • C23C8/38—Treatment of ferrous surfaces

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)

Abstract

PURPOSE: A method for treating multistage deviation of plasma diffusion nitriding of steel components is provided to be used as varieties of precision mechanical components by sequentially masking the required area and plasma diffusion nitriding after each masking, thereby simultaneously achieving a required deviation of non-strain surface hardening and residual surface compression stress. CONSTITUTION: The method comprises the processes of solution heat treating steel for structural at a temperature of 850 deg.C for 1 hour and oil cooling the steel; completing component processing by tempering the oil cooled steel at a temperature of 690 deg.C for 2 hours and oil cooling the tempered steel; first masking a non-treated surface part (4) with a thermally stable material such as a metal foil or ceramic; treating D.C pulsed plasma diffusion nitriding having a main constituent of nitrogen on the first masked steel and furnace cooling the plasma diffusion nitrided steel; second plasma diffusion nitriding the resulting steel in the same conditions as the first masking for 3 hours by masking the first plasma diffusion nitrided low concentrated nitrogen diffusion part (5) in the same method as in the first treatment as maintaining the masking of the first masked area, and furnace cooling the second plasma diffusion nitrided steel so that a medium concentrated nitrogen diffusion part (6) is formed; and forming a high concentrated nitrogen diffusion part (7) by third masking the second treated medium concentrated nitrogen diffusion part (6) in the same conditions as in the first and second treatments as maintaining the first and second maskings in the same method, third plasma diffusion nitriding the resulting steel for 3 hours in the same method and furnace cooling the third plasma diffusion nitrided steel, thereby forming a high concentrated nitrogen diffusion part (7); and furnace cooling the high concentrated nitrogen diffusion part.

Description

철강 부품의 플라즈마 확산질화 다단계 편차처리 방법Plasma Diffusion Nitriding Multi-Step Deviation Method for Steel Parts

본 발명은 철강재의 편차처리 방법에 관한 것으로, 연질 뜨임처리 후, 정밀 가공한 부품의 표면을 요구 부위별로 차등적인 표면경화처리 및 표면 압축 잔류 응력화를 수반함과 동시에 내구성을 극대화할 수 있는 플라즈마 확산질화 다단계 편차처리 방법에 관한 것이다.The present invention relates to a method for processing a deviation of steel, and after soft tempering treatment, the surface of the precisely processed parts is accompanied by a differential surface hardening treatment and surface compressive residual stress for each required part, and at the same time, it can maximize the durability The present invention relates to a diffusion nitriding multi-step deviation processing method.

종래의 편차 표면강화 처리는 편차 탄화처리로서 후속 급냉 및 뜨임시 처리된 철강부품의 변형을 수반하며, 표면 압축 잔류응력을 유지할 수 없었다.The conventional deviation surface hardening treatment is a deviation carbonization treatment, which involves deformation of the steel parts treated in subsequent quenching and tempering, and cannot maintain the surface compressive residual stress.

다른 종래기술로는 부품표면에 편차 쇼트 블라스팅(shot blasting)으로 편차 표면(가공)경화와 동시에 표면압축 잔류 응력화를 시킬 수 있었으나, 이때 표면조도의 증가로 변형을 수반하여 마찰면으로 사용할 수 없으므로 정밀기계 부품의 표면개질 처리로서는 부적당하였다.Another conventional technique was to perform surface compression residual stress at the same time as the deviation surface (processing) hardening by deviation shot blasting on the part surface, but at this time, it cannot be used as friction surface with deformation due to increase of surface roughness. It was unsuitable for surface modification of precision machine parts.

또 다른 종래 기술로는 확산 질화처리로서 가스 확산질화, 염욕 확산질화, 플라즈마 확산질화 처리가 있으며, 대개 590℃ 이하의 약질화 분위기에서 질소 확산층을 형성시킨다.Further conventional techniques include gas diffusion nitriding, salt bath diffusion nitriding and plasma diffusion nitriding treatment as diffusion nitriding treatments, which form a nitrogen diffusion layer in a weakening atmosphere of usually 590 占 폚 or lower.

그러나 상술한 확산질화 처리는, 무변형 표면경화 및 압축 잔류 응력화는 가능하였지만 다단계 편차처리는 불가능하였다. 즉, 부품 표면의 무처리 요구부위를 완전 마스킹(masking)한 후, 확산질화 처리함으로써 무처리부위와 처리부위만 남게 되었다. 이것은 마스킹 방법의 편차성이 개발되지 않아 편차 확산질화 처리가 불가능하였다.However, in the above-mentioned diffusion nitriding treatment, the deformation-free surface hardening and the compressive residual stress were possible, but the multi-step deviation treatment was impossible. That is, after completely masking the untreated parts on the surface of the part, diffusion nitriding treatment leaves only the untreated parts and the treated parts. This was because the variation of the masking method was not developed and the deviation diffusion nitriding treatment was impossible.

본 발명은 위와 같은 종래의 편차 확산질화 처리에 있어서의 문제점을 감안하여 이를 해소하기 위한 것으로, 그 목적으로 하는 바는, 요구 부위의 순차적인 마스킹과 매 마스킹 후 플라즈마 확산질화 처리를 실시하여 무변형 요구편차 표면 경화와 동시에 표면 압축 잔류 응력화를 달성하여 각종의 정밀기계부품으로서 사용할 수 있는 플라즈마 확산질화 다단계 편차처리 방법을 제공하는 것이다.The present invention has been made in view of the problems in the conventional deviation diffusion nitriding treatment as described above, and its object is to provide a non-deformation by performing a plasma diffusion nitriding treatment after sequential masking and every masking of the required portion. The present invention provides a plasma diffusion nitriding multi-step deviation processing method which can be used as various precision machine parts by achieving surface compression residual stress at the same time as required deviation surface hardening.

제1도는 무변형 편차 표면강화 및 압축잔류 응력화를 위해 확산질화 편차처리된 철강부품의 표면부위 단면도이다.FIG. 1 is a cross-sectional view of the surface of a steel part subjected to diffusion nitriding deviation for stress free deformation and compressive residual stress.

* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings

1 : 철강 내부 2 : 철강 표면1: steel inside 2: steel surface

3 : 확산질화처리 도중 또는 후속 확산질화처리중 내부로 확산하는 질소원자3: Nitrogen atom diffuses into the inside during diffusion nitriding or during subsequent diffusion nitriding

4 : 무처리 표면부(소재경도)4: Untreated surface part (material hardness)

5 : 저농도 질소 확산부(저경도 및 저 압축잔류 응력부)5: low concentration nitrogen diffusion part (low hardness and low compression residual stress part)

6 : 중농도 질소 확산부(중경도 및 중 압축잔류 응력부)6: medium concentration nitrogen diffusion (medium hardness and medium compressive residual stress)

7 : 고농도 질소 확산부(고경도 및 고 압축잔류 응력부)7: High concentration nitrogen diffusion part (high hardness and high compressive residual stress part)

상기 목적을 달성하기 위한 본 발명의 플라즈마 확산질화 다단계 편차처리 방법은, 무변형 표면경화 및 압축잔류 응력화 처리를 편차로 처리되기를 원하는 철강부품 연질표면의 횟수만큼, 마스킹 횟수를 높여가면서 확산질화 처리를 동일 횟수만큼 계속함으로써, 마스킹을 가장 많은 횟수로 받은 부위는 표면경도와 압축잔류 응력이 낮고 최후까지 마스킹을 받지 않은 부위가 표면경도와 압축잔류 응력이 높은 부위가 되어 편차성이 나타나며, 이 편차성은 확산질화 처리변수를 조정하므로써, 또한 조정할 수 있도록 하여 상술한 문제점을 해결하는 것이다.Plasma diffusion nitriding multi-stage deviation treatment method of the present invention for achieving the above object, diffusion nitriding treatment while increasing the number of masking by the number of soft surface of the steel parts that want to be treated as a non-deformation surface hardening and compressive residual stress treatment By continuing the same number of times, the area that received the highest number of maskings had a low surface hardness and compressive residual stress, and a part that had not been masked until the last became a region having high surface hardness and compressive residual stress, resulting in a deviation. The above-mentioned problem is solved by adjusting the diffusion nitriding process variable so that it can also be adjusted.

[실시예]EXAMPLE

구조용강 소재를 용체화 처리한 후, 충분히 뜨임 처리하여 잔류응력을 제거한 후, 원하는 형상 및 치수로 마지막 부품가공을 마친다. 예를 들면 구조용강 SCM 440을 850℃에서 1시간동안 용체화 처리한 후, 유냉하고 난 후 690℃에서 2시간 동안 뜨임 처리를 하고 유냉하여 부품으로 가공한다.After the structural steel material is subjected to solution treatment, it is tempered sufficiently to remove residual stress, and then the final part processing is completed in the desired shape and dimensions. For example, structural steel SCM 440 is subjected to solution treatment at 850 ° C. for 1 hour, and then cooled to oil and then tempered at 690 ° C. for 2 hours, and then cooled to oil into parts.

본 열처리후 표면경도는 HVI 값을 나타낸다.The surface hardness after the heat treatment indicates the HVI value.

제1도는 무변형 편차 표면강화 및 압축잔류 응력화를 위해 확산질화 편차처리된 철강부품의 표면부위 단면도이다.FIG. 1 is a cross-sectional view of the surface of a steel part subjected to diffusion nitriding deviation for stress free deformation and compressive residual stress.

부호 3은 내부로 확산하는 질소원자를 나타낸다.3 represents the nitrogen atom which diffuses inward.

본 부품을 표면경화 및 압축잔류 응력화가 필요하지 않은 부분, 즉 무처리 표면부(4)를 열적으로 안정한 물질, 예를들면 금속박, 세라믹 등으로 간단히 둘러싼 후(1차 마스킹) 아래 표와 같은 플라즈마 확산질화 조건으로 처리를 실시하여 노냉한다.The part is not required to harden the surface hardening and compressive residual stress, that is, simply wrapped around the untreated surface (4) with a thermally stable material, such as metal foil, ceramics (primary masking), and then plasma as shown in the table below. Treatment is carried out under diffusion nitridation conditions to cool the furnace.

상기 처리에 의한 재료는 변형이 없고, 처리된 부위는 질소확산층만 형성하여 표면경도는 570HVI 값을 나타낸다. 무처리부(1차 마스킹 부위)의 표면경도는 여전히 소재 표면경도 270 HVI값을 나타낸다.The material obtained by the above treatment is free of deformation, and the treated portion forms only a nitrogen diffusion layer, and the surface hardness shows a value of 570 HVI. The surface hardness of the untreated portion (primary masking site) still shows the material surface hardness of 270 HVI.

1차 마스킹한 부위의 마스킹을 유지한 채, 1차 플라즈마 확산질화 처리된 부분의 일부, 즉 저농도 질소 확산부(5)를 상기 1차 처리와 동일하게 마스킹하여 1차와 동일한 조건에서 3시간 동안 2차 플라즈마 확산질화 처리를 실시하여 노냉한다.While maintaining masking of the primary masked portion, a portion of the primary plasma diffusion nitriding treatment, that is, the low concentration nitrogen diffusion portion 5, was masked in the same manner as the primary treatment for 3 hours under the same conditions as the primary treatment. The secondary plasma diffusion nitriding treatment is performed to cool the furnace.

상기 1차, 2차 처리에 의하여 마스킹 된 부위, 즉 무처리 표면부(4)는 소재경도와 같은 270 HVI 값을 나타내지만, 제 2차 부분에서만 마스킹된 부위, 즉 저농도 질소 확산부(5)는 1차 처리 때의 표면질소가 2차 처리시 열을 받아 부품 내부로 확산이 일어나 표면경도가 570에서 470HVI로 감소하고, 1차 및 2차 처리시 모두 처리된 부위는 표면경도 570HVI 값을 나타낸다.The portion masked by the first and second treatments, that is, the untreated surface portion 4, exhibits the same 270 HVI value as the material hardness, but the portion masked only in the secondary portion, that is, the low concentration nitrogen diffusion portion 5 The surface nitrogen during the primary treatment receives heat during the secondary treatment and diffuses into the component, reducing the surface hardness from 570 to 470 HVI, and the treated region shows the surface hardness of 570 HVI in both the primary and secondary treatments. .

같은 방법으로 1차 및 2차 마스킹을 유지한 채, 2차 처리된 부분의 일부, 즉 중농도 질소 확산부(6)를 1, 2차 처리와 동일조건으로 3차 마스킹하고, 동일조건으로 3시간 동안 3차 플라즈마 확산질화 처리를 실시하여 노냉한다.In the same way, while maintaining the primary and secondary masking, a portion of the secondary treated portion, that is, a medium nitrogen diffusion portion 6, is subjected to third masking under the same conditions as the primary and secondary treatments, and 3 The furnace is subjected to a third plasma diffusion nitriding treatment for a time in which the furnace is cooled.

이 처리에 의하여 무처리 표면부(4)는 소재경도와 같은 270HVI 값을 나타내지만, 2차 마스킹된 저농도 질소 확산부(5)는 표면질소가 3차 처리시 열을 받아 부품내부로 더욱 확산되어 표면 압축 잔류응력은 감소되어 표면경도도 470에서 400HVI으로 더욱 감소한다.By this treatment, the untreated surface portion 4 exhibits the same 270HVI value as the hardness of the material, but the second masked low concentration nitrogen diffusion portion 5 is further diffused into the part due to the heat of the surface nitrogen being subjected to the third treatment. The surface compressive residual stress is reduced, further reducing the surface hardness from 400 to 640 HVI.

한편, 3차에서만 마스킹된 부위, 즉 중농도 질소 확산부(6)는 2차 처리에서의 경도 570에서 470HVI으로 감소하고, 3차 처리시 계속 처리된 부분, 즉 고농도 질소 확산부(7)는 표면경도 570 HVI 값을 유지한다.On the other hand, the portion masked only in the third order, that is, the medium nitrogen diffusion section 6 is reduced from the hardness of 570 to 470HVI in the secondary treatment, and the portion continuously processed during the third treatment, that is, the high concentration nitrogen diffusion section 7 Maintain a surface hardness of 570 HVI.

상술한 바와 같은 처리공정을 가지는 본 발명의 플라즈마 확산질화 다단계 편차처리 방법은, 저합금강 기계부품 연질표면을 요구부위에 따라 플라즈마 확산질화 처리를 함과 동시에 마스킹을 여러 번 조합 작업하므로써, 부품표면에 취성이 큰 질화물을 형성시키지 않게 된다.In the plasma diffusion nitridation multistage deviation processing method of the present invention having the above-described processing step, the surface of the parts surface is combined by performing plasma diffusion nitridation treatment on the soft alloy surface of the low alloy steel machine parts according to the required area, and at the same time by masking multiple times. It will not form brittle nitrides.

반면에, 표면압축 잔류응력이 크고 표면경도도 큰 질소 확산층을 형성시키며, 부품치수 변화도 거의 없어 후가공도 불필요하며, 상술한 바와 같은 조합 작업으로 요구부위별로 원하는 표면경도 편차성을 확보할 수 있게 되어 부품의 부위별 기능을 증가시킬 수 있는 효과가 있다.On the other hand, it forms a nitrogen diffusion layer with a large surface compressive residual stress and a large surface hardness, almost no change in component size, and thus no post-processing is required. There is an effect that can increase the function of each part of the part.

Claims (1)

구조용강 소재를 850℃에서 1시간동안 용체화 처리하고 유냉하는 공정과, 690℃에서 2시간 동안 뜨임 처리를 하고 유냉하여 부품으로 가공완료하는 공정과, 무처리 표면부(4)를 열적으로 안정한 물질(금속박, 세라믹)로 1차 마스킹하는 공정과, 질소를 주성분으로 하는 직류펄스 플라즈마 확산질화 처리를 실시하고 노냉하는 공정과, 1차 마스킹한 부위의 마스킹을 유지한 채 1차 플라즈마 확산질화 처리된 저농도 질소 확산부(5)를 상기 1차 처리와 동일하게 마스킹하여 1차와 동일한 조건에서 3시간 동안 2차 플라즈마 확산질화 처리 및 노냉을 실시하여 중농도 질소 확산부(6)를 형성하는 공정과, 같은 방법으로 1차 및 2차 마스킹을 유지한 채, 2차 처리된 중농도 질소 확산부(6)를 1, 2차 처리와 동일조건으로 3차 마스킹하고, 동일조건으로 3시간 동안 3차 플라즈마 확산질화 처리 및 노냉을 실시하여 고농도 질소 확산부(7)를 형성하고 노냉하는 공정으로 이루어진 것을 특징으로 하는 철강부품의 플라즈마 확산질화 다단계 편차처리 방법.Process to melt and structurally structuralize structural steel materials for 1 hour at 850 ℃, temper treatment at 690 ℃ for 2 hours, complete the process of cooling by oil to complete parts, and thermally stable untreated surface part 4 Primary masking process using a material (metal foil, ceramic), direct current pulse plasma diffusion nitriding treatment with nitrogen as the main component, and furnace cooling, and primary plasma diffusion nitriding treatment while maintaining masking of the primary masked portion Masking the low concentration nitrogen diffusion unit 5 in the same manner as the primary treatment, and performing the secondary plasma diffusion nitriding treatment and furnace cooling for 3 hours under the same conditions as the primary treatment to form the medium concentration nitrogen diffusion unit 6. And, while maintaining the primary and secondary masking in the same manner, the secondary treated medium-density nitrogen diffusion section 6 is subjected to third masking under the same conditions as the first and second treatments, and for three hours under the same conditions. Tea plastic Do diffusion and nitriding treatment carried out by the high concentration of nitrogen diffusion portion 7 is formed and a plasma process spread nitride multi-level variations in processing steel parts, characterized by being a furnace cooling of the furnace cooling method.
KR1019950047713A 1995-12-08 1995-12-08 The plasma diffusion nitrizing for steel KR100250220B1 (en)

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Publication number Priority date Publication date Assignee Title
JPH05202464A (en) * 1992-01-27 1993-08-10 Parker Netsushiyori Kogyo Kk Method for partially nitriding parts

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05202464A (en) * 1992-01-27 1993-08-10 Parker Netsushiyori Kogyo Kk Method for partially nitriding parts

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