KR101326800B1 - High Strength Martensite Type Free Cutting Stainless Steel - Google Patents
High Strength Martensite Type Free Cutting Stainless Steel Download PDFInfo
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- KR101326800B1 KR101326800B1 KR1020110138451A KR20110138451A KR101326800B1 KR 101326800 B1 KR101326800 B1 KR 101326800B1 KR 1020110138451 A KR1020110138451 A KR 1020110138451A KR 20110138451 A KR20110138451 A KR 20110138451A KR 101326800 B1 KR101326800 B1 KR 101326800B1
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
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Abstract
본 발명은 내식성이 향상된 고강도 쾌삭 스테인레스강에 관한 것으로서,
C: 0 초과 0.08 중량% 이하, Si: 0 초과 1.00 중량% 이하, Mn: 0 초과 1.25 중량% 이하, P: 0 초과 0.060 중량% 이하, S: 0.06 내지 0.08 중량%, Ni: 0 초과 0.60 중량% 이하, Cr: 10.00 내지 10.50 중량%를 포함하고, 나머지는 Fe 및 불가피적 불순물로 구성되는 것을 특징으로 하여,
황 함유량이 절감됨과 아울러 몰리브덴을 사용하지 않아도 되어 염가이며 내식성이 향상되고 담금질, 뜨임의 열처리를 생략할 수 있는 고강도 쾌삭 스테인레스강에 관한 것이다.The present invention relates to a high strength free cutting stainless steel with improved corrosion resistance,
C: greater than 0 and 0.08 wt% or less, Si: greater than 0 and 1.00 wt% or less, Mn: greater than 0 and 1.25 wt% or less, P: greater than 0 and 0.060 wt% or less, S: 0.06 and 0.08 wt% or less, Ni: greater than 0 and 0.60 wt% % Or less, Cr: 10.00 to 10.50% by weight, the remainder is composed of Fe and inevitable impurities,
The present invention relates to a high-strength free-cut stainless steel that can reduce sulfur content and eliminate molybdenum, which is inexpensive, improves corrosion resistance, and eliminates heat treatment of quenching and tempering.
Description
본 발명은 고강도 쾌삭 스테인레스강에 관한 것으로서, 특히 염가이고, 내식성이 향상되며, 담금질, 뜨임의 열처리를 생략할 수 있는 고강도 쾌삭 스테인레스강에 관한 것이다.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to high strength free-cutting stainless steels, and particularly, to high-strength free-cutting stainless steels that are inexpensive, have improved corrosion resistance, and can eliminate heat treatment of quenching and tempering.
쾌삭강(快削鋼, free cutting steel)은 강도를 너무 떨어뜨리지 않고 절삭하기 쉽도록 개량한 강(鋼)을 말한다. 스테인레스강 중 쾌삭강으로서는 SAE(Society of Automotive Engineers) grade로 type 416(이하 "SUS 416"이라 한다)인 마르텐사이트(martensite)계 스테인레스강이 사용된다. SUS 416은 다른 스테인레스강에 비하여 추가로 황(S)을 포함하여 기계 가공을 용이하게 한다.Free cutting steel refers to steel that has been improved to be easy to cut without degrading its strength too much. Among the stainless steels, martensitic stainless steels of type 416 (hereinafter referred to as "SUS 416") are used as SAE (Society of Automotive Engineers) grade. SUS 416 contains sulfur (S) in addition to other stainless steels to facilitate machining.
SUS 416은 일반적으로 약 0.3 중량%의 황을 함유하고 있다. SUS 416 내의 황은 주로 망간(Mn)과 결합하여 MnS 등의 비금속 개재물로 철강 중에 분산되어 절삭 시에 파쇄되기 쉬워지므로 강의 피삭성이 향상된다. 이러한 SUS 416은 프린터 등의 샤프트, 절삭 도구, 기계 부품, 석유 정제 장치, 펌프 샤프트 등에 사용된다. SUS 416 generally contains about 0.3% by weight of sulfur. Sulfur in SUS 416 is mainly bonded with manganese (Mn) and dispersed in steel with non-metallic inclusions, such as MnS, so that it is easy to be crushed at the time of cutting, thereby improving the machinability of the steel. Such SUS 416 is used in shafts such as printers, cutting tools, machine parts, petroleum refining apparatuses, pump shafts, and the like.
그러나, SUS 416에 포함된 황은 가격을 증가시킨다. 또한, SUS 416에 포함된 황은 내식성을 저하시킨다. 또한, SUS 416으로부터 황 또는 황 화합물(예를 들면, 황화수소(H2S), 이산화황(SO2))이 기체로 방출될 수 있다. 그리고, SUS 416은 경화를 위한 담금질(quenching)이나 내부 응력을 제거하기 위한 뜨임(tempering) 등의 처리가 필요할 수 있다.However, sulfur contained in SUS 416 increases the price. In addition, sulfur contained in SUS 416 lowers the corrosion resistance. In addition, sulfur or sulfur compounds (eg, hydrogen sulfide (H 2 S), sulfur dioxide (SO 2 )) may be released as a gas from SUS 416. In addition, the SUS 416 may require a treatment such as quenching for curing or tempering to remove internal stress.
그리고 SUS 416은 크롬(Cr)은 산화에 대한 저항력을 증가시키기 위해 사용되고, 황을 포함하는 환경에서 균열을 방지하기 위해 몰리브덴(Mo)이 사용된다. 그러나, 이러한 크롬과 몰리브덴 또한 상당히 고가이기 때문에 최종 생산물의 가격을 증가시키는 원인이 되고 있었다.
And SUS 416 is chromium (Cr) is used to increase the resistance to oxidation, molybdenum (Mo) is used to prevent cracking in the environment containing sulfur. However, these chromium and molybdenum are also quite expensive, causing the price of the final product to increase.
본 발명은 상술한 문제점을 극복하기 위해 안출된 것으로서, 황 함유량을 절감하여 몰리브덴의 사용을 배제함으로써 염가이며 내식성을 향상시키고 담금질, 뜨임의 열처리를 생략할 수 있는 고강도 쾌삭 스테인레스강을 제공하는 것을 목적으로 한다.
The present invention has been made to overcome the above-mentioned problems, the object of the present invention is to provide a high-strength free-cut stainless steel that can reduce the sulfur content and eliminate the use of molybdenum, which is inexpensive and improves corrosion resistance and can omit the heat treatment of quenching and tempering. It is done.
상술한 목적을 달성하기 위해 본 발명은, C: 0 초과 0.08 중량% 이하, Si: 0 초과 1.00 중량% 이하, Mn: 0 초과 1.25 중량% 이하, P: 0 초과 0.060 중량% 이하, S: 0.06 내지 0.08 중량%, Ni: 0 초과 0.60 중량% 이하, Cr: 10.00 내지 10.50 중량%를 포함하고, 나머지는 Fe 및 불가피적 불순물로 구성되며, 마르텐사이트상인 금속 조직을 갖는 고강도 쾌삭 스테인레스강을 제공한다.
In order to achieve the above object, the present invention is C: more than 0 0.08% by weight or less, Si: more than 0 more than 1.00% by weight, Mn: more than 0 1.25% by weight or less, P: more than 0 0.060% by weight or less, S: 0.06 To 0.08% by weight, Ni: greater than 0 and 0.60% by weight, Cr: 10.00 to 10.50% by weight, the remainder consisting of Fe and unavoidable impurities, providing a high strength free-cutting stainless steel having a metallic structure that is martensitic. .
상술한 본 발명에 따른 고강도 쾌삭 스테인레스강은 황 함유량이 절감됨으로써 몰리브덴을 사용하지 않아도 되어 염가이며 내식성이 향상되고 담금질, 뜨임의 열처리를 생략할 수 있다.
The high strength free cutting stainless steel according to the present invention described above does not require molybdenum due to the reduction of sulfur content, which is inexpensive, improves corrosion resistance, and eliminates heat treatment of quenching and tempering.
이하, 본 발명을 상세하게 설명한다.Hereinafter, the present invention will be described in detail.
본 발명에서는 황 함유량을 절감하여 몰리브덴의 사용을 배제함으로써 염가이며 내식성을 향상시키고 담금질, 뜨임의 열처리를 생략할 수 있는 고강도 쾌삭 스테인레스강을 제공하기 위해 C: 0 초과 0.08 중량% 이하, Si: 0 초과 1.00 중량% 이하, Mn: 0 초과 1.25 중량% 이하, P: 0 초과 0.060 중량% 이하, S: 0.06 내지 0.08 중량%, Ni: 0 초과 0.60 중량% 이하, Cr: 10.00 내지 10.50 중량%를 포함하고, 나머지는 Fe 및 불가피적 불순물로 구성되어, 마르텐사이트(martensite)상의 금속조직을 갖는 고강도 쾌삭 스테인레스 강을 제안한다.In the present invention, by reducing the sulfur content to eliminate the use of molybdenum in order to provide a high-strength free-cut stainless steel that is inexpensive, improves corrosion resistance and can omit the heat treatment of quenching, tempering, Si: more than 0.08% by weight, Si: 0 Greater than 1.00 weight percent or less, Mn: greater than 0 and 1.25 weight percent or less, P: greater than 0 and 0.060 weight percent or less, S: 0.06 to 0.08 weight percent, Ni: greater than 0 and 0.60 weight percent or less, Cr: 10.00 to 10.50 weight percent The remainder consists of Fe and unavoidable impurities, suggesting a high strength free cutting stainless steel having a martensite-like metal structure.
탄소(C)는 오스테나이트(austenite)상 형성 원소이고 고온에서 페라이트(ferrite)상을 억제하며 마르텐사이트상의 고용 경화에 효과적이다. 그러나, C의 함량이 너무 높은 경우 내식성을 감소시킨다. 그리하여 본 발명에서 C 함량을 0 초과 0.08 중량% 이하 범위에서 결정한다.Carbon (C) is an austenite phase forming element, suppresses the ferrite phase at high temperatures, and is effective in solid solution hardening of the martensite phase. However, if the content of C is too high, the corrosion resistance is reduced. Thus, in the present invention, the C content is determined in the range of more than 0 and 0.08% by weight or less.
규소(Si)는 탈산을 위한 원소로서 필요하다. 그러나, Si의 함량이 너무 높은 경우 내식성의 열화를 초래한다. 그리하여 본 발명에서 Si 함량을 0 초과 1.00 중량% 이하 범위에서 결정한다.Silicon (Si) is needed as an element for deoxidation. However, if the content of Si is too high, deterioration of corrosion resistance is caused. Thus, the Si content in the present invention is determined in the range of more than 0 to 1.00 wt% or less.
망간(Mn)은 오스테나이트상의 안정성을 지배하는 원소이다. 그러나, Mn의 함량이 너무 높은 경우 마르텐사이트상의 유도가 방해된다. 그리하여 본 발명에서 Mn의 함량은 0 초과 1.25 중량% 이하 범위에서 결정한다.Manganese (Mn) is an element that governs the stability of the austenite phase. However, if the Mn content is too high, the induction on martensite is hindered. Therefore, the content of Mn in the present invention is determined in the range of more than 0 to 1.25% by weight or less.
인(P)은 황(S)과 함께 쾌삭성을 향상시키기 위해 사용된다. 그러나, P의 함량이 너무 높은 경우 내식성을 감소시킨다. 본 발명에서 P의 함량은 SUS 416과 동일하게 0 초과 0.060 중량% 이하 범위에서 결정한다.Phosphorus (P) is used together with sulfur (S) to improve the free machinability. However, if the content of P is too high, the corrosion resistance is reduced. In the present invention, the content of P is determined in the range of more than 0 and less than 0.060 wt%, similarly to SUS 416.
황(S)은 쾌삭성을 향상시키기 위해 사용된다. 그러나, S는 내식성 및 열간 가공성을 저하시킨다. 본 발명에서 S의 함량은 0.06 내지 0.08 중량% 범위에서 결정한다.Sulfur (S) is used to improve the free machinability. However, S reduces corrosion resistance and hot workability. In the present invention, the content of S is determined in the range of 0.06 to 0.08% by weight.
니켈(Ni)은 내식성을 향상시키기 위해 사용된다. 본 발명에서 Ni의 함량은 SUS 416과 동일하게 0 초과 0.60 중량% 이하 범위에서 결정한다.Nickel (Ni) is used to improve the corrosion resistance. In the present invention, the content of Ni is determined in the range of more than 0 and less than 0.60% by weight, like SUS 416.
크롬(Cr)은 산화에 대한 저항력을 증가시키기 위해 사용된다. 본 발명에서 Cr의 함량은 10.00 내지 10.50 중량% 범위에서 결정한다.
Chromium (Cr) is used to increase the resistance to oxidation. In the present invention, the content of Cr is determined in the range of 10.00 to 10.50% by weight.
상술한 성분들을 포함하는 강철재는 용제화 처리되고, 용제화 처리된 강철재는 냉간 가공된다. 냉간 가공된 강철재는 마르텐사이트상을 갖는다. 본 발명에 따른 스테인레스강은 냉간 가공에 의해 고강도가 되고, 담금질, 뜨임 등의 열처리가 생략 가능하다.
The steel material containing the above-mentioned components is solvent-treated, and the solvent-treated steel material is cold worked. Cold worked steel has a martensite phase. The stainless steel according to the present invention has high strength by cold working, and heat treatment such as quenching and tempering can be omitted.
표 1은 시험한 실시예의 화학적 조성값과 SUS 416의 화학적 조성값을 나타낸다. 표 1에서 단위는 중량%이다.
Table 1 shows the chemical composition values of the examples tested and the chemical composition values of SUS 416. In Table 1, the unit is wt%.
표 1의 실시예와 SUS 416을 동일한 감면률(26%)로 지름 6mm로 냉간 인발 처리하였다. 이들의 기계적 성질은 표 2와 같다.
The Example of Table 1 and SUS 416 were cold drawn to a diameter of 6 mm with the same reduction rate (26%). Their mechanical properties are shown in Table 2.
표 2를 보면, 실시예 1, 2에 따른 기계적 성질은 크게 차이가 없는 것을 알 수 있다. 실험 오차를 감안한다면 거의 동일한 기계적 성질을 갖는 것이다. 그리고 SUS 416과 비교하여 보더라도 황의 함량이 적고 몰리브덴(Mo)이 포함되지 않았음에도 인장강도, 경도가 약간 낮은값을 가지지만 양자는 거의 동등한 기계적 성질을 갖는 것을 볼 수 있다. Looking at Table 2, it can be seen that the mechanical properties according to Examples 1 and 2 are not significantly different. Considering the experimental error, it has almost the same mechanical properties. Compared with SUS 416, although the sulfur content is low and molybdenum (Mo) is not included, the tensile strength and hardness are slightly lower, but both have almost the same mechanical properties.
표 1의 실시예와 SUS 416의 내식 성능을 살펴보기 위하여, 5% H2SO4 용액, 25℃와 5% HCl 용액, 25℃에서 부식 시험을 하였고, 그 결과는 표 3과 같다. 표 3에서 단위는 g/m2·h이다.
In order to examine the corrosion resistance of the Examples of Table 1 and SUS 416, 5% H 2 SO 4 solution, 25 ℃ and 5% HCl solution, was tested for corrosion at 25 ℃, the results are shown in Table 3. In Table 3, the unit is g / m 2 · h.
표 3을 보면, 실시예 1, 2에 따른 스테인레스강은 SUS 416에 비해 내식성이 우수한 것을 볼 수 있다.Looking at Table 3, it can be seen that the stainless steels according to Examples 1 and 2 are superior in corrosion resistance than SUS 416.
다음으로, 표 1의 실시예와 SUS 416의 피삭성을 시험하였다. 비교를 위하여 SUS 303에 대하여도 피삭성을 시험하였다. 피삭성 시험은 피절삭 가공시 절삭 공구의 마모량을 통해 시험하였다. Φ3mm의 드릴을 이용하여 전체 천공 길이가 1m가 되도록 천공을 한 후, Φ3mm의 드릴의 날끝 마모 길이를 측정하였다. 마모 길이가 짧을수록 우수한 피삭성을 갖는다. 그 결과는 다음의 표 4와 같다.
Next, the machinability of the Example of Table 1 and SUS 416 was tested. Machinability was also tested for SUS 303 for comparison. The machinability test was conducted through the amount of wear of the cutting tool in the cutting operation. After drilling was performed so that the total drilling length was 1 m using a drill of Φ 3 mm, the blade tip wear length of the drill of Φ 3 mm was measured. The shorter the wear length, the better the machinability. The results are shown in Table 4 below.
표 4를 보면, 실시예에 따른 스테인레스강의 피삭성은 SUS 416과 거의 유사하고 SUS 303에 비하여는 뛰어난 것을 볼 수 있다.Looking at Table 4, the machinability of the stainless steel according to the embodiment can be seen that it is almost similar to SUS 416 and superior to SUS 303.
Claims (1)
C: greater than 0 and 0.08 wt% or less, Si: greater than 0 and 1.00 wt% or less, Mn: greater than 0 and 1.25 wt% or less, P: greater than 0 and 0.060 wt% or less, S: 0.06 and 0.08 wt% or less, Ni: greater than 0 and 0.60 wt% % Or less, Cr: 10.00 to 10.50% by weight, the content of the S relative to each component is specified, including the remainder is composed of Fe and unavoidable impurities, characterized in that the high-strength martensite system having a metallic structure that is martensitic Free cutting stainless steel.
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| KR1020110138451A KR101326800B1 (en) | 2011-12-20 | 2011-12-20 | High Strength Martensite Type Free Cutting Stainless Steel |
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| KR1020110138451A KR101326800B1 (en) | 2011-12-20 | 2011-12-20 | High Strength Martensite Type Free Cutting Stainless Steel |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020001394A (en) * | 2000-06-28 | 2002-01-09 | 이구택 | Martensite Stainless Steel With Low Hardness and Method For Manufacturing The Same |
| KR100717506B1 (en) * | 2005-12-22 | 2007-05-14 | 주식회사 포스코 | A manufacturing method of a martensitic stainless steel with low hardness |
| KR20090066864A (en) * | 2007-12-20 | 2009-06-24 | 주식회사 포스코 | Method for manufacturing a martensitic stainless steel |
| KR20110043192A (en) * | 2009-10-21 | 2011-04-27 | (주)지앤지텍 | High strength martensite type free cutting stainless steel and making method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020001394A (en) * | 2000-06-28 | 2002-01-09 | 이구택 | Martensite Stainless Steel With Low Hardness and Method For Manufacturing The Same |
| KR100717506B1 (en) * | 2005-12-22 | 2007-05-14 | 주식회사 포스코 | A manufacturing method of a martensitic stainless steel with low hardness |
| KR20090066864A (en) * | 2007-12-20 | 2009-06-24 | 주식회사 포스코 | Method for manufacturing a martensitic stainless steel |
| KR20110043192A (en) * | 2009-10-21 | 2011-04-27 | (주)지앤지텍 | High strength martensite type free cutting stainless steel and making method thereof |
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