TW202132586A

TW202132586A - Precipitation hardening martensitic stainless steel

Info

Publication number: TW202132586A
Application number: TW110102917A
Authority: TW
Inventors: 髙橋伸幸; 岡本晃彦; 古庄千紘; 高林宏之; 小柳禎彦
Original assignee: 日商大同特殊鋼股份有限公司
Priority date: 2020-02-04
Filing date: 2021-01-27
Publication date: 2021-09-01
Also published as: JP2021123792A; TWI764540B

Abstract

The present invention relates to a precipitation-hardening martensitic stainless steel, containing: 0 < C < 0.10 mass %, 0 < Si ≤ 0.20 mass %, 0 < Mn ≤ 1.00 mass %, 8.0 mass % ≤ Ni ≤ 15.0 mass %, 8.0 mass % ≤ Cr ≤ 14.0 mass %, 0.4 mass % ≤ Nb ≤ 2.50 mass %, and the balance being Fe and inevitable impurities.

Description

沉澱硬化麻田散鐵系不鏽鋼Precipitation hardening Asada loose iron series stainless steel

本發明係關於一種沉澱硬化麻田散鐵系不鏽鋼，及更特定言之係關於一種於室溫下之強度及韌度優異及於低溫下之韌度優異的沉澱硬化麻田散鐵系不鏽鋼。The present invention relates to a precipitation hardening Matian bulk iron-based stainless steel, and more specifically, it relates to a precipitation-hardening Matian bulk iron-based stainless steel having excellent strength and toughness at room temperature and excellent toughness at low temperatures.

沉澱硬化不鏽鋼係指其中將少量Al、Cu、Mo、Ti、或其類似物添加至Cr-Ni不鏽鋼，且金屬間化合物藉由熱處理沉澱於基質相中的鋼。沉澱硬化不鏽鋼根據基質相的結構而被分類為麻田散鐵系不鏽鋼、半沃斯田鐵系不鏽鋼、及沃斯田鐵系不鏽鋼。其中，沉澱硬化麻田散鐵系不鏽鋼諸如SUS 630、PH 13-8 Mo、或Custom 465的抗腐蝕性、強度、及韌度優異，及因此被使用於航空太空結構元件或其類似者中。Precipitation hardening stainless steel refers to steel in which a small amount of Al, Cu, Mo, Ti, or the like is added to Cr-Ni stainless steel, and intermetallic compounds are precipitated in the matrix phase by heat treatment. Precipitation hardening stainless steels are classified into Matian scattered iron-based stainless steel, semi-austrian iron-based stainless steel, and austenitic iron-based stainless steel according to the structure of the matrix phase. Among them, precipitation hardening Asada scattered iron-based stainless steels such as SUS 630, PH 13-8 Mo, or Custom 465 are excellent in corrosion resistance, strength, and toughness, and therefore are used in aerospace structural components or the like.

關於此一沉澱硬化麻田散鐵系不鏽鋼，迄今為止已作出各種提案。舉例來說，專利文獻1揭示一種其中分散及沉澱金屬間化合物的沉澱硬化麻田散鐵系不鏽鋼，該麻田散鐵系不鏽鋼包含0.1質量%以下的C、11質量%以上及13質量%以下的Cr、7.5質量%以上及11質量%以下的Ni、0.9質量%以上及1.7質量%以下的Al、0.85質量%以上及1.35質量%以下的Mo、1.75質量%以上及2.75質量%以下的W，及其餘為Fe及無可避免的雜質，其中Mo含量及W含量滿足預定關係。該文獻描述此一沉澱硬化麻田散鐵系不鏽鋼在機械強度與韌度之間具有高度平衡且具有優異的抗腐蝕性。Regarding this precipitation hardening Asada bulk iron stainless steel, various proposals have been made so far. For example, Patent Document 1 discloses a precipitation hardening Asada bulk iron-based stainless steel in which intermetallic compounds are dispersed and precipitated. The Asada bulk iron-based stainless steel contains 0.1% by mass or less of C, and 11% by mass or more and 13% by mass or less of Cr. , 7.5% by mass or more and 11% by mass or less of Ni, 0.9% by mass or more and 1.7% by mass or less of Al, 0.85% by mass or more and 1.35% by mass or less Mo, 1.75% by mass or more and 2.75% by mass or less W, and The rest are Fe and unavoidable impurities, in which the content of Mo and the content of W meet the predetermined relationship. The document describes that this precipitation hardening Asada scattered iron stainless steel has a high balance between mechanical strength and toughness and has excellent corrosion resistance.

專利文獻2揭示一種沉澱硬化麻田散鐵系不鏽鋼，其以質量計包含，C: 0.1%以下，Cr: 11%至13%，Ni: 10.5%至11.5%，Al: 0.25%以下，Ti: 0.9%至1.5%，Mo + 0.5 W: 0.5%至1.5%，Si: 1.0%以下，Mn: 1.0%以下，Mo/W (質量%比): 0.4至0.6，及其餘係鐵及無可避免的雜質。該文獻描述此一沉澱硬化麻田散鐵系不鏽鋼具有優異的結構穩定性、機械特性、及抗腐蝕性。Patent Document 2 discloses a precipitation hardening Asada scattered iron-based stainless steel, which contains, by mass, C: 0.1% or less, Cr: 11% to 13%, Ni: 10.5% to 11.5%, Al: 0.25% or less, and Ti: 0.9 % To 1.5%, Mo + 0.5 W: 0.5% to 1.5%, Si: 1.0% or less, Mn: 1.0% or less, Mo/W (mass% ratio): 0.4 to 0.6, and the rest are iron and unavoidable Impurities. The document describes that this precipitation hardening Matian scattered iron stainless steel has excellent structural stability, mechanical properties, and corrosion resistance.

專利文獻3揭示一種沉澱硬化麻田散鐵系不鏽鋼，其以質量計包含，0.1%以下之C，0.1%以下之N，9.0%以上及14.0%以下之Cr，9.0%以上及14.0%以下之Ni，0.5%以上及2.5%以下之Mo，0.5%以下之Si，1.0%以下之Mn，0.25%以上及1.75%以下之Ti，0.25%以上及1.75%以下之Al，及其餘係Fe及無可避免的雜質。該文獻描述此一沉澱硬化麻田散鐵系不鏽鋼具有優異的結構穩定性、強度、韌度、及抗腐蝕性且不需要深冷處理(sub-zero treatment)。Patent Document 3 discloses a precipitation hardening Matian scattered iron-based stainless steel, which contains, by mass, 0.1% or less of C, 0.1% or less of N, 9.0% or more and 14.0% or less of Cr, and 9.0% or more and 14.0% or less of Ni , 0.5% or more and 2.5% or less Mo, 0.5% or less Si, 1.0% or less Mn, 0.25% or more and 1.75% or less Ti, 0.25% or more and 1.75% or less Al, and the rest are Fe and no Impurities to avoid. The document describes that this precipitation hardening Asada scattered iron stainless steel has excellent structural stability, strength, toughness, and corrosion resistance and does not require sub-zero treatment.

專利文獻4揭示一種沉澱硬化麻田散鐵系不鏽鋼，其以質量計包含，0.05%以下之C，0.05%以下之N，10.0%以上及14.0%以下之Cr，8.5%以上及11.5%以下之Ni，0.5%以上及3.0%以下之Mo，1.5%以上及2.0%以下之Ti，0.25%以上及1.00%以下之Al，0.5%以下之Si，1.0%以下之Mn，及其餘係Fe及無可避免的雜質。該文獻描述此一沉澱硬化麻田散鐵系不鏽鋼具有優異的結構穩定性、強度、韌度、及抗腐蝕性且不需要深冷處理。Patent Document 4 discloses a precipitation hardening Asada scattered iron stainless steel, which contains, by mass, 0.05% or less of C, 0.05% or less of N, 10.0% or more and 14.0% or less of Cr, and 8.5% or more and 11.5% or less of Ni , 0.5% or more and 3.0% or less Mo, 1.5% or more and 2.0% or less Ti, 0.25% or more and 1.00% or less Al, 0.5% or less Si, 1.0% or less Mn, and the rest are Fe and no Impurities to avoid. The document describes that this precipitation hardening Asada scattered iron stainless steel has excellent structural stability, strength, toughness, and corrosion resistance and does not require cryogenic treatment.

專利文獻5揭示一種抗腐蝕性麻時效合金(maraging alloy)，其不為沉澱硬化麻田散鐵系不鏽鋼但包含47.4重量%至82.4重量%之Fe，6重量%至9重量%之Ni，11重量%至15重量%之Cr，0.5重量%至6重量%之Mo + 1/2 W，各0至6重量%之Co及Cu中之一或多者、各0至1重量%之Ti、Nb、Al、Si、Mn、及V中之一或多者，各0至0.1重量%之稀土或複合金屬中之一或多者，0至0.1重量%之C及N，及0.1重量%至0.5重量%之Be。該文獻描述此一抗腐蝕性麻時效合金可獲得550 HV以上之高硬度同時於時效硬化(age hardening)後維持現有的抗腐蝕性。Patent Document 5 discloses a corrosion-resistant maraging alloy (maraging alloy), which is not a precipitation hardening Asada scattered iron stainless steel but contains 47.4 wt% to 82.4 wt% Fe, 6 wt% to 9 wt% Ni, and 11 wt% % To 15% by weight of Cr, 0.5% to 6% by weight of Mo + 1/2 W, each of 0 to 6% by weight of one or more of Co and Cu, each of 0 to 1% by weight of Ti, Nb One or more of, Al, Si, Mn, and V, each of 0 to 0.1 wt% of one or more of rare earth or composite metals, 0 to 0.1 wt% of C and N, and 0.1 wt% to 0.5 Weight% of Be. The document describes that this anticorrosive hemp ageing alloy can obtain high hardness above 550 HV while maintaining the existing corrosion resistance after age hardening.

此外，專利文獻6揭示一種麻田散鐵系不鏽鋼，其包含C: 0.15%以下 (不包括0)，Si: 6.0%以下 (不包括0)，Mn: 10.0%以下 (不包括0)，Ni: 8.0% 以下 (不包括0)，Cr: 10.0%至17.0%，N: 0.3%以下 (不包括0)，Mo: 4.0%以下 (包括0)，Cu: 4.0%以下 (包括不添加)，Co: 4.0%以下 (包括0)，Ni當量值係在8.0至17.5之範圍內，及其餘係Fe及無可避免的雜質。該文獻描述當對此一麻田散鐵系不鏽鋼進行適當熱處理時，疲勞特性獲得改良。In addition, Patent Document 6 discloses an Asada scattered iron-based stainless steel, which contains C: 0.15% or less (excluding 0), Si: 6.0% or less (excluding 0), Mn: 10.0% or less (excluding 0), and Ni: 8.0% or less (excluding 0), Cr: 10.0% to 17.0%, N: 0.3% or less (excluding 0), Mo: 4.0% or less (including 0), Cu: 4.0% or less (including no addition), Co : Below 4.0% (including 0), the Ni equivalent value is within the range of 8.0 to 17.5, and the rest is Fe and unavoidable impurities. This document describes that when this Asada scattered iron-based stainless steel is properly heat-treated, the fatigue characteristics are improved.

沉澱硬化麻田散鐵系不鏽鋼之特徵在於微細沉澱物經分散而獲得強度。例如，在PH 13-8 Mo中，使用Al作為強化元素，且NiAl經沉澱而獲得高強度及高韌度(強韌度)。在Custom 465中，使用Ti作為強化元素，且Ni₃ Ti經沉澱而獲得強韌度。然而，習知之沉澱硬化麻田散鐵系不鏽鋼在低溫下易碎，及因此其在低溫下的用途受到限制。此外，在相關技藝中尚未提出即使在低溫下亦展現高韌度的沉澱硬化麻田散鐵系不鏽鋼。The precipitation hardening Asada scattered iron-based stainless steel is characterized in that the fine precipitates are dispersed to obtain strength. For example, in PH 13-8 Mo, Al is used as a strengthening element, and NiAl is precipitated to obtain high strength and high toughness (toughness). In Custom 465, Ti is used as a strengthening element, and Ni ₃ Ti is precipitated to obtain toughness. However, the conventional precipitation hardening Matian scattered iron stainless steel is fragile at low temperatures, and therefore its use at low temperatures is limited. In addition, there has not yet been proposed in the related art that precipitation hardening Asada scattered iron-based stainless steel exhibiting high toughness even at low temperatures.

專利文獻1：JP-A-2015-093991 專利文獻2：JP-A-2014-201792 專利文獻3：JP-A-2013-147698 專利文獻4：JP-A-2013-001949 專利文獻5：JP-A-H09-143626 專利文獻6：JP-A-H04-173926Patent Document 1: JP-A-2015-093991 Patent Document 2: JP-A-2014-201792 Patent Document 3: JP-A-2013-147698 Patent Document 4: JP-A-2013-001949 Patent Document 5: JP-A-H09-143626 Patent Document 6: JP-A-H04-173926

本發明之一目的係提供一種於室溫下之強度及韌度優異及於低溫下之韌度優異的沉澱硬化麻田散鐵系不鏽鋼。One of the objects of the present invention is to provide a precipitation hardening Matian scattered iron stainless steel with excellent strength and toughness at room temperature and excellent toughness at low temperature.

為解決以上問題，根據本發明之沉澱硬化麻田散鐵系不鏽鋼包含： 0 ＜ C ＜ 0.10質量%， 0 ＜ Si ≤ 0.20質量%， 0 ＜ Mn ≤ 1.00質量%， 8.0質量% ≤ Ni ≤ 15.0質量%， 8.0質量% ≤ Cr ≤ 14.0質量%， 0.4質量% ≤ Nb ≤ 2.50質量%，及其餘係Fe及無可避免的雜質。In order to solve the above problems, the precipitation hardening Matian scattered iron stainless steel according to the present invention includes: 0 ＜ C ＜ 0.10 mass%, 0 <Si ≤ 0.20 mass%, 0 <Mn ≤ 1.00 mass%, 8.0 mass% ≤ Ni ≤ 15.0 mass%, 8.0% by mass ≤ Cr ≤ 14.0% by mass, 0.4% by mass ≤ Nb ≤ 2.50% by mass, and The rest are Fe and inevitable impurities.

在習知之沉澱硬化麻田散鐵系不鏽鋼中，鮮少使用Nb作為強化元素。此係由於當添加Nb時，易產生有害的相。然而，當向沉澱硬化麻田散鐵系不鏽鋼添加適量的Nb作為強化元素及於適當條件下進行熱處理時，在室溫下展現高強度及高韌度，且即使在低溫下亦展現高韌度。當添加適量的Nb及在適當條件下進行熱處理時，Ni₃ Nb沉澱於基質相中。據認為在低溫下之高韌度的表現與沉澱Ni₃ Nb晶粒的形狀及Ni₃ Nb晶粒與基質相之間的一致性有關。Nb is rarely used as a strengthening element in the conventional precipitation hardening Asada scattered iron stainless steel. This is because when Nb is added, harmful phases are easily produced. However, when an appropriate amount of Nb is added as a strengthening element to the precipitation hardening Asada scattered iron-based stainless steel and heat-treated under appropriate conditions, it exhibits high strength and high toughness at room temperature, and high toughness even at low temperatures. When an appropriate amount of Nb is added and heat treatment is performed under appropriate conditions, Ni ₃ Nb precipitates in the matrix phase. It is believed that the performance of high toughness at low temperature is related to the shape of the _{precipitated Ni 3} _{Nb crystal grains and the consistency between the Ni 3} Nb crystal grains and the matrix phase.

以下，將詳細說明本發明之一具體例。 [1. 沉澱硬化麻田散鐵系不鏽鋼] [1.1. 主要組成元素] 根據本發明之沉澱硬化麻田散鐵系不鏽鋼包含以下元素，其餘係Fe及無可避免的雜質。添加元素之種類、其含量範圍、及其限制理由如下。Hereinafter, a specific example of the present invention will be described in detail. [1. Precipitation-hardened Asada scattered iron series stainless steel] [1.1. Main components] The precipitation hardening Asada scattered iron-based stainless steel according to the present invention contains the following elements, the rest being Fe and unavoidable impurities. The types of additional elements, their content ranges, and the reasons for their limitation are as follows.

(1) 0 ＜ C ＜ 0.10質量%： C使M₂ X型氮化碳沉澱且有助於改良基底金屬的強度。此外，C亦有助於細化先前的沃斯田鐵晶粒直徑。為獲得該等效應，C含量需大於0質量%。C含量較佳係0.0005質量%以上，及更佳係0.0020質量%以上。另一方面，當C含量過大時，由於大量M₂ X型氮化碳沉澱，因此變得需要提高固溶體溫度。因此，沃斯田鐵晶粒在固溶體時變粗，其導致特性變化。此外，在時效處理時，(Cr, Mo)碳化物過度沉澱，且韌度及抗腐蝕性劣化。此外，麻田散鐵轉變起始溫度(Ms點)降低而使沃斯田鐵相穩定。因此，C含量需低於0.10質量%。C含量較佳係0.05質量%以下，及更佳係0.01質量%以下。(1) 0 <C <0.10% by mass: C precipitates M ₂ X-type carbon nitride and contributes to improving the strength of the base metal. In addition, C also helps to refine the grain diameter of the previous austenitic iron. In order to obtain these effects, the C content needs to be greater than 0% by mass. The C content is preferably 0.0005 mass% or more, and more preferably 0.0020 mass% or more. On the other hand, when the C content is too large, since a large amount of M ₂ X-type carbon nitride is precipitated, it becomes necessary to increase the solid solution temperature. Therefore, the austenitic iron crystal grains become coarser in solid solution, which leads to changes in characteristics. In addition, during aging treatment, (Cr, Mo) carbides are excessively precipitated, and toughness and corrosion resistance deteriorate. In addition, the initiation temperature (Ms point) of the Madian scattered iron transformation is lowered to stabilize the Austrian iron phase. Therefore, the C content needs to be less than 0.10% by mass. The C content is preferably 0.05% by mass or less, and more preferably 0.01% by mass or less.

(2) 0 ＜ Si ≤ 0.20質量%： Si用作去氧劑。當Si含量過小時，在溶解時的去氧化不足，且潔淨度降低。因此，Si含量需大於0質量%。Si含量較佳為0.005質量%以上。另一方面，當Si含量過大時，形成氧化物夾雜物，且韌度降低。因此，Si含量需為0.20質量%以下。Si含量較佳為0.15質量%以下，及更佳為0.10質量%以下。(2) 0 <Si ≤ 0.20% by mass: Si is used as an oxygen scavenger. When the Si content is too small, the deoxidation during dissolution is insufficient, and the cleanliness is reduced. Therefore, the Si content needs to be greater than 0% by mass. The Si content is preferably 0.005 mass% or more. On the other hand, when the Si content is too large, oxide inclusions are formed, and toughness decreases. Therefore, the Si content needs to be 0.20% by mass or less. The Si content is preferably 0.15% by mass or less, and more preferably 0.10% by mass or less.

(3) 0 ＜ Mn ≤ 1.00質量%： Mn具有降低作為雜質混合之S之晶界偏析的效應。為獲得此一效應，Mn含量需大於0質量%。Mn含量較佳為0.005質量%以上。另一方面，當Mn含量過大時，硫化物增加且韌度降低。此外，Ms點降低且沃斯田鐵相穩定。因此，Mn含量需為1.00質量%以下。Mn含量較佳為0.50質量%以下，及更佳為0.20質量%以下。(3) 0 <Mn ≤ 1.00 mass%: Mn has the effect of reducing the grain boundary segregation of S mixed as impurities. In order to obtain this effect, the Mn content needs to be greater than 0% by mass. The Mn content is preferably 0.005 mass% or more. On the other hand, when the Mn content is too large, sulfides increase and toughness decreases. In addition, the Ms point is lowered and the austenitic iron phase is stable. Therefore, the Mn content needs to be 1.00 mass% or less. The Mn content is preferably 0.50% by mass or less, and more preferably 0.20% by mass or less.

(4) 8.0質量% ≤ Ni ≤ 15.0質量%： Ni係使諸如NiAl或Ni₃ (Al, Ti)之金屬間化合物相沉澱的重要元素且有助於改良基底金屬的強度。此外，Ni具有抑制δ肥粒鐵相形成的作用。此外，Ni降低基質相的延脆轉換(ductile-brittle transition)溫度(DBTT)，且有助於改良室溫下的韌度。為獲得該等效應，Ni含量需為8.0質量%以上。Ni含量較佳為9.0質量%以上，及更佳為10.0質量%以上。另一方面，當Ni含量過大時，Ms點降低。因此，殘留沃斯田鐵增加，且強度減低。因此，Ni含量需為15.0質量%以下。Ni含量較佳為13.5質量%以下，及更佳為13.0質量%以下。(4) 8.0% by mass ≤ Ni ≤ 15.0% by mass: Ni is _{an important element that precipitates intermetallic compound phases such as NiAl or Ni 3} (Al, Ti) and helps to improve the strength of the base metal. In addition, Ni has the effect of inhibiting the formation of δ ferrite phase. In addition, Ni reduces the ductile-brittle transition temperature (DBTT) of the matrix phase and helps to improve the toughness at room temperature. In order to obtain these effects, the Ni content needs to be 8.0% by mass or more. The Ni content is preferably 9.0% by mass or more, and more preferably 10.0% by mass or more. On the other hand, when the Ni content is too large, the Ms point decreases. Therefore, the residual austenitic iron increases and the strength decreases. Therefore, the Ni content needs to be 15.0% by mass or less. The Ni content is preferably 13.5% by mass or less, and more preferably 13.0% by mass or less.

(5) 8.0質量% ≤ Cr ≤ 14.0質量%： Cr有助於調整Ms點，及當Cr含量減小時，Ms點提高。因此，當Cr含量減小時，於固溶體熱處理後或於深冷處理後的殘留沃斯田鐵減少。藉此，微結構的均勻度獲得改良，且0.2%保證應力(proof stress)獲得改良。另一方面，Cr係確保抗腐蝕性所需的元素。當Cr含量小時。M₂₃ C₆ 型碳化物(其較M₂ X型氮化碳粗)經穩定，且0.2%保證應力減小。因此，Cr含量需為8.0質量%以上。Cr含量較佳為8.5質量%以上。(5) 8.0% by mass ≤ Cr ≤ 14.0% by mass: Cr helps to adjust the Ms point, and when the Cr content decreases, the Ms point increases. Therefore, when the Cr content decreases, the residual austenitic iron after the solid solution heat treatment or the cryogenic treatment decreases. In this way, the uniformity of the microstructure is improved, and the 0.2% proof stress is improved. On the other hand, Cr is an element required to ensure corrosion resistance. When the Cr content is small. The M ₂₃ C ₆ type carbide (which is _{coarser than the M 2} X type carbon nitride) is stabilized, and 0.2% guarantees a reduction in stress. Therefore, the Cr content needs to be 8.0% by mass or more. The Cr content is preferably 8.5% by mass or more.

另一方面，當Cr含量增加時，Ms點降低。因此，當Cr含量過大時，於時效處理前的殘留沃斯田鐵量過大，且0.2%保證應力減小，此外，當Cr含量過大時，易形成δ肥粒鐵相。因此，Cr含量需為14.0質量%以下。Cr含量較佳為12.0質量%以下，及更佳為10.0質量%以下。On the other hand, when the Cr content increases, the Ms point decreases. Therefore, when the content of Cr is too large, the amount of residual austenitic iron before aging treatment is too large, and 0.2% guarantees the reduction of stress. In addition, when the content of Cr is too large, the δ ferrite phase is easy to form. Therefore, the Cr content needs to be 14.0% by mass or less. The Cr content is preferably 12.0% by mass or less, and more preferably 10.0% by mass or less.

(6) 0.4質量% ≤ Nb ≤ 2.50質量%： Nb使具有2 nm至20 nm之寬度及約數十nm之長度的桿狀Ni₃ Nb晶粒沉澱，且有助於改良基底金屬的強度。當將Al或Ti添加至鋼中時，亦即，當鋼中包含諸如NiAl或Ni₃ (Al, Ti)的金屬間化合物時，Nb形成Ni (Al, Nb)、Ni₃ (Al, Ti, Nb)或其類似物，其中NiAl或Ni₃ (Al, Ti)中之一部分的Al或Ti經Nb取代，其有助於改良基底金屬的強度。此外，Nb形成氮化碳且有助於細化晶粒。為獲得該等效應，Nb含量需為0.4質量%以上。Nb含量較佳為0.50質量%以上，及更佳為0.60質量%以上。 _{(6) 0.4% by mass ≤ Nb ≤ 2.50% by mass: Nb precipitates rod-shaped Ni 3} Nb crystal grains having a width of 2 nm to 20 nm and a length of about tens of nm, and helps to improve the strength of the base metal. When Al or Ti is added to steel, that is, when the steel contains _{intermetallic compounds such as NiAl or Ni 3} (Al, Ti), Nb forms Ni (Al, Nb), Ni ₃ (Al, Ti, Nb) or its analogues, wherein a _{part of Al or Ti in NiAl or Ni 3} (Al, Ti) is replaced by Nb, which helps to improve the strength of the base metal. In addition, Nb forms carbon nitride and helps to refine crystal grains. In order to obtain these effects, the Nb content needs to be 0.4% by mass or more. The Nb content is preferably 0.50% by mass or more, and more preferably 0.60% by mass or more.

另一方面，當Nb含量過大時，沉澱強化相及夾雜物增加，且韌度劣化。此外，當Nb含量過大時，易形成δ肥粒鐵相。因此，Nb含量需為2.50質量%以下。Nb含量較佳為1.50質量%以下，及更佳為1.00質量%以下。On the other hand, when the Nb content is too large, the precipitation strengthening phase and inclusions increase, and the toughness deteriorates. In addition, when the Nb content is too large, it is easy to form a δ ferrite phase. Therefore, the Nb content needs to be 2.50% by mass or less. The Nb content is preferably 1.50% by mass or less, and more preferably 1.00% by mass or less.

(7)無可避免的雜質：在本發明中，「無可避免的雜質」係指於不鏽鋼之製造期間自原料或耐火材料併入的痕量組分。無可避免的雜質明確地包括下列。 (a) P ≤ 0.050質量%： P使鋼的韌度及延展性劣化。此外，P使因晶界偏析引起的熱加工性劣化。然而，在P含量為0.050質量%以下的情況中，存在極少副作用。(7) Inevitable impurities: In the present invention, "inevitable impurities" refer to trace components incorporated from raw materials or refractory materials during the manufacture of stainless steel. The unavoidable impurities specifically include the following. (a) P ≤ 0.050 mass%: P deteriorates the toughness and ductility of steel. In addition, P deteriorates hot workability due to grain boundary segregation. However, in the case where the P content is 0.050% by mass or less, there are very few side effects.

(b) S ≤ 0.050質量%： S使鋼的韌度及延展性劣化。此外，S使因晶界偏析引起的熱加工性劣化。此外，S鍵結至Ti從而形成硫化物夾雜物。然而，在S含量為0.050質量%以下的情況中，存在極少副作用。(b) S ≤ 0.050 mass%: S deteriorates the toughness and ductility of steel. In addition, S deteriorates hot workability due to grain boundary segregation. In addition, S is bonded to Ti to form sulfide inclusions. However, in the case where the S content is 0.050% by mass or less, there are very few side effects.

(c) N ≤ 0.050質量%： N形成氮化物及使韌度及延展性劣化。此外，N降低Ms點及使沃斯田鐵相穩定。然而，在N含量為0.050質量%以下的情況中，存在極少副作用。N含量較佳為0.03質量%以下，及更佳為0.01質量%以下。(c) N ≤ 0.050 mass%: N forms nitrides and deteriorates toughness and ductility. In addition, N reduces the Ms point and stabilizes the austenitic iron phase. However, in the case where the N content is 0.050% by mass or less, there are very few side effects. The N content is preferably 0.03% by mass or less, and more preferably 0.01% by mass or less.

(d) O ≤ 0.010質量%： O形成氧化物夾雜物及使韌度劣化。然而，在O含量為0.010質量%以下的情況中，存在極少副作用。(d) O ≤ 0.010 mass%: O forms oxide inclusions and deteriorates toughness. However, in the case where the O content is 0.010% by mass or less, there are very few side effects.

(e) Al ＜ 0.10質量%： (f) Ti ＜ 0.10質量%：如稍後將作說明，Al及Ti係使金屬間化合物沉澱的元素且有助於改良基底金屬的強度，且亦係可作為無可避免的雜質混合的元素。當將Al及Ti處理為無可避免的雜質時，Al及Ti各限制為低於0.10質量%。此外，當將Al及Ti處理為無可避免的雜質時，其下限無需特別限制且係0質量%。(e) Al <0.10% by mass: (f) Ti <0.10 mass%: As will be described later, Al and Ti are elements that precipitate intermetallic compounds and contribute to improving the strength of the base metal, and are also elements that can be mixed as unavoidable impurities. When Al and Ti are treated as unavoidable impurities, Al and Ti are each limited to less than 0.10% by mass. In addition, when Al and Ti are treated as unavoidable impurities, the lower limit does not need to be particularly limited and is 0% by mass.

(g) Cu ＜ 0.30質量%：當Cu係呈痕量時，存在改良強度而不大大地減損韌度的效應，而當Cu含量過大時，韌度及熱加工性在一些情況中會劣化。因此，Cu含量的上限值受限於低於0.30質量%，較佳低於0.10質量%。此外，當Cu係作為無可避免的雜質混合時，其下限無需特別限制且係0質量%。(g) Cu <0.30% by mass: When the Cu system is in a trace amount, there is an effect of improving the strength without greatly degrading the toughness, and when the Cu content is too large, the toughness and hot workability may deteriorate in some cases. Therefore, the upper limit of the Cu content is limited to less than 0.30% by mass, preferably less than 0.10% by mass. In addition, when the Cu system is mixed as an unavoidable impurity, the lower limit does not need to be particularly limited and is 0% by mass.

(h) Mo ＜ 0.10質量%： (i) W ＜ 0.10質量%： (j) Co ＜ 0.10質量%： (k) V ＜ 0.30質量%：如稍後將作說明，Mo、W、Co、及V各係有助於改良基底金屬之強度的元素，且亦係可作為無可避免的雜質混合的元素。當將Mo、W、Co、及V處理為無可避免的雜質時，Mo、W、Co、及V各受限於低於以上各別值。此外，當將Mo、W、Co、及V處理為無可避免的雜質時，其下限無需特別限制且係0質量%。(h) Mo <0.10 mass%: (i) W <0.10 mass%: (j) Co <0.10% by mass: (k) V <0.30% by mass: As will be explained later, Mo, W, Co, and V are elements that contribute to improving the strength of the base metal, and are also elements that can be mixed as unavoidable impurities. When Mo, W, Co, and V are treated as unavoidable impurities, Mo, W, Co, and V are each restricted to be lower than the respective values above. In addition, when Mo, W, Co, and V are treated as inevitable impurities, the lower limit does not need to be particularly limited and is 0% by mass.

[1.2. 次組成元素] 根據本發明之沉澱硬化麻田散鐵系不鏽鋼除了前述元素外，可進一步包含一種或兩種或更多種以下元素。添加元素之種類、其含量範圍、及其限制理由如下。[1.2. Sub-components] The precipitation hardening Asada scattered iron-based stainless steel according to the present invention may further contain one or two or more of the following elements in addition to the aforementioned elements. The types of additional elements, their content ranges, and the reasons for their limitation are as follows.

(8) 0.10質量% ≤ Al ≤ 2.50質量%： Al與Ni形成金屬間化合物(2 nm至20 nm之球形NiAl)，且有助於改良基底金屬的強度。此外，Al亦作用為去氧元素。為獲得該等效應，Al含量可為0.10質量%以上。Al含量更佳為0.30質量%以上，進一步較佳為0.50質量%以上，及甚至更佳為0.70質量%以上。另一方面，當Al含量過大時，沉澱強化相及夾雜物增加，且韌度劣化。此外，當Al含量過大時，易形成δ肥粒鐵相。因此，Al含量較佳為2.50質量%以下。Al含量更佳為2.00質量%以下，及進一步較佳為1.50質量%以下。(8) 0.10 mass% ≤ Al ≤ 2.50 mass%: Al and Ni form an intermetallic compound (spherical NiAl from 2 nm to 20 nm) and help to improve the strength of the base metal. In addition, Al also acts as a deoxidizing element. In order to obtain these effects, the Al content may be 0.10% by mass or more. The Al content is more preferably 0.30% by mass or more, further preferably 0.50% by mass or more, and even more preferably 0.70% by mass or more. On the other hand, when the Al content is too large, the precipitation strengthening phase and inclusions increase, and the toughness deteriorates. In addition, when the Al content is too large, the δ ferrite phase is easy to form. Therefore, the Al content is preferably 2.50% by mass or less. The Al content is more preferably 2.00% by mass or less, and still more preferably 1.50% by mass or less.

(9) 0.10質量% ≤ Ti ≤ 1.50質量%：如同Al，Ti與Ni形成金屬間化合物(具有約2 nm至20 nm之寬度及約數十nm之長度的桿狀Ni₃ Ti)，且有助於改良基底金屬的強度。結果，晶界強度獲得改良，其有助於改良韌度。此外，Ti形成氮化碳且有助於細化晶粒。為獲得該等效應，Ti含量較佳為0.10質量%以上。另一方面，當Ti含量過大時，沉澱強化相及夾雜物增加，且韌度劣化。此外，當Ti含量過大時，易形成δ肥粒鐵相。因此，Ti含量較佳為1.50質量%以下。Ti含量更佳為1.30質量%以下，及進一步較佳為1.10質量%以下。(9) 0.10 mass% ≤ Ti ≤ 1.50 mass%: Like Al, Ti and Ni form an intermetallic compound (a rod-shaped Ni ₃ Ti with a width of about 2 nm to 20 nm and a length of about tens of nm), and Helps improve the strength of the base metal. As a result, the grain boundary strength is improved, which helps to improve the toughness. In addition, Ti forms carbon nitride and helps to refine crystal grains. In order to obtain these effects, the Ti content is preferably 0.10% by mass or more. On the other hand, when the Ti content is too large, the precipitation strengthening phase and inclusions increase, and the toughness deteriorates. In addition, when the Ti content is too large, the δ ferrite phase is easy to form. Therefore, the Ti content is preferably 1.50% by mass or less. The Ti content is more preferably 1.30% by mass or less, and still more preferably 1.10% by mass or less.

可添加Ti及Al中之任一者，或可添加Ti及Al兩者。然而，當Al含量為0.10質量%以上及2.50質量%以下時，Ti含量較佳低於0.10質量%。此係由於在改良強度而不減損韌度的效應上，Ni (Al, Nb)金屬間化合物優於Ni (Ti, Nb)金屬間化合物。Either Ti and Al may be added, or both Ti and Al may be added. However, when the Al content is 0.10% by mass or more and 2.50% by mass or less, the Ti content is preferably less than 0.10% by mass. In this system, Ni (Al, Nb) intermetallic compounds are superior to Ni (Ti, Nb) intermetallic compounds in terms of improving strength without degrading toughness.

(10) 0.10質量% ≤ Co ≤ 10.0質量%： Co具有促進影響強度之微細沉澱物相沉澱的作用。為獲得此一效應，Co含量較佳為0.10質量%以上。Co含量更佳為3.0質量%以上，及進一步較佳為6.0質量%以上。另一方面，當Co含量過大時，成本上升。因此，Co含量較佳為10.0質量%以下。Co含量更佳為9.0質量%以下，及進一步較佳為8.0質量%以下。(10) 0.10 mass% ≤ Co ≤ 10.0 mass%: Co has the effect of promoting the precipitation of the fine precipitate phase that affects the strength. In order to obtain this effect, the Co content is preferably 0.10% by mass or more. The Co content is more preferably 3.0% by mass or more, and further preferably 6.0% by mass or more. On the other hand, when the Co content is too large, the cost increases. Therefore, the Co content is preferably 10.0% by mass or less. The Co content is more preferably 9.0% by mass or less, and still more preferably 8.0% by mass or less.

(11) 0.10 質量% ≤ Mo ≤ 3.0質量%： Mo使M₂ X型氮化碳沉澱且有助於改良基底金屬的強度。Mo亦有助於細化先前的沃斯田鐵晶粒直徑。此外，Mo有助於改良強度、韌度、及抗腐蝕性。為獲得該等效應，Mo含量較佳為0.10質量%以上。Mo含量更佳為0.3質量%以上，及進一步較佳為0.5質量%以上。另一方面，當Mo含量過大時，由於大量M₂ X型氮化碳沉澱而變得需要提高固溶體溫度。因此，沃斯田鐵晶粒在固溶體時變粗，其導致特性變化。此外，當Mo含量過大時，易形成δ肥粒鐵相。因此，Mo含量較佳為3.0質量%以下。Mo含量更佳為2.5質量%以下，及進一步較佳為2.0質量%以下。(11) 0.10% by mass ≤ Mo ≤ 3.0% by mass: Mo precipitates M ₂ X-type carbon nitride and contributes to improving the strength of the base metal. Mo also helps to refine the grain diameter of the previous austenitic iron. In addition, Mo helps to improve strength, toughness, and corrosion resistance. In order to obtain these effects, the Mo content is preferably 0.10% by mass or more. The Mo content is more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more. On the other hand, when the Mo content is too large, it becomes necessary to increase the solid solution temperature _{due to the precipitation of a large amount of M 2 X-type carbon nitride.} Therefore, the austenitic iron crystal grains become coarser in solid solution, which leads to changes in characteristics. In addition, when the content of Mo is too large, it is easy to form a δ ferrite phase. Therefore, the Mo content is preferably 3.0% by mass or less. The Mo content is more preferably 2.5% by mass or less, and further preferably 2.0% by mass or less.

(12) 0.10質量% ≤ W ≤ 3.0質量%： W使M₂ X型氮化碳沉澱且有助於改良基底金屬的強度。W亦有助於細化先前的沃斯田鐵晶粒直徑。此外，W有助於改良強度、韌度、及抗腐蝕性。為獲得該等效應，W含量較佳為0.10質量%以上。W含量更佳為0.3質量%以上，及進一步較佳為0.5質量%以上。另一方面，當W含量過大時，由於大量M₂ X型氮化碳沉澱而變得需要提高固溶體溫度。因此，沃斯田鐵晶粒在固溶體時變粗，其導致特性變化。此外，當W含量過大時，易形成δ肥粒鐵相。因此，W含量較佳為3.0質量%以下。W含量更佳為2.5質量%以下，及進一步較佳為2.0質量%以下。(12) 0.10% by mass ≤ W ≤ 3.0% by mass: W precipitates M ₂ X-type carbon nitride and helps to improve the strength of the base metal. W also helps to refine the grain diameter of the previous austenitic iron. In addition, W helps to improve strength, toughness, and corrosion resistance. In order to obtain these effects, the W content is preferably 0.10% by mass or more. The W content is more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more. On the other hand, when the W content is too large, it becomes necessary to increase the solid solution temperature _{due to the precipitation of a large amount of M 2 X-type carbon nitride.} Therefore, the austenitic iron crystal grains become coarser in solid solution, which leads to changes in characteristics. In addition, when the W content is too large, the δ ferrite phase is easy to form. Therefore, the W content is preferably 3.0% by mass or less. The W content is more preferably 2.5% by mass or less, and further preferably 2.0% by mass or less.

(13) 0.3質量% ≤ V ≤ 2.0質量%：當將Al或Ti添加至鋼中時，亦即，當鋼中包含諸如NiAl或Ni₃ (Al, Ti)的金屬間化合物時，V形成Ni (Al, V)、Ni₃ (Al, Ti, V)或其類似物，其中NiAl或Ni₃ (Al, Ti)中之一部分的Al或Ti經V取代，藉此有助於改良基底金屬的強度。此外，V形成氮化碳且有助於細化晶粒。為獲得該等效應，V含量較佳為0.3質量%以上。(13) 0.3% by mass ≤ V ≤ 2.0% by mass: When Al or Ti is added to steel, that is, when _{an intermetallic compound such as NiAl or Ni 3} (Al, Ti) is included in the steel, V forms Ni (Al, V), Ni ₃ (Al, Ti, V) or the like, where a _{part of Al or Ti in NiAl or Ni 3} (Al, Ti) is replaced by V, thereby helping to improve the base metal strength. In addition, V forms carbon nitride and helps to refine crystal grains. In order to obtain these effects, the V content is preferably 0.3% by mass or more.

另一方面，當V含量過大時，沉澱強化相及夾雜物增加，且韌度劣化。此外，當V含量過大時，易形成δ肥粒鐵相。因此，V含量較佳為2.0質量%以下。V含量更佳為1.5質量%以下，及進一步較佳為1.0質量%以下。On the other hand, when the V content is too large, the precipitation strengthening phase and inclusions increase, and the toughness deteriorates. In addition, when the V content is too large, the δ ferrite phase is easy to form. Therefore, the V content is preferably 2.0% by mass or less. The V content is more preferably 1.5% by mass or less, and further preferably 1.0% by mass or less.

(14) 0.01質量% ≤ Ta ≤ 1.0質量%：當將Al或Ti添加至鋼中時，亦即，當鋼中包含諸如NiAl或Ni₃ (Al, Ti)的金屬間化合物時，Ta形成Ni (Al, Ta)、Ni₃ (Al, Ti, Ta)或其類似物，其中NiAl或Ni₃ (Al, Ti)中之一部分的Al或Ti經Ta取代，藉此有助於改良基底金屬的強度。此外，Ta形成氮化碳且有助於細化晶粒。為獲得該等效應，Ta含量較佳為0.01質量%以上。(14) 0.01% by mass ≤ Ta ≤ 1.0% by mass: When Al or Ti is added to steel, that is, when _{an intermetallic compound such as NiAl or Ni 3} (Al, Ti) is included in the steel, Ta forms Ni (Al, Ta), Ni ₃ (Al, Ti, Ta) or the like, where a _{part of Al or Ti in NiAl or Ni 3} (Al, Ti) is replaced by Ta, thereby helping to improve the base metal strength. In addition, Ta forms carbon nitride and helps to refine crystal grains. In order to obtain these effects, the Ta content is preferably 0.01% by mass or more.

另一方面，當Ta含量過大時，沉澱強化相及夾雜物增加，且韌度劣化。此外，當Ta含量過大時，易形成δ肥粒鐵相。因此，Ta含量較佳為1.0質量%以下。On the other hand, when the Ta content is too large, the precipitation strengthening phase and inclusions increase, and the toughness deteriorates. In addition, when the content of Ta is too large, the δ ferrite phase is easy to form. Therefore, the Ta content is preferably 1.0% by mass or less.

(15) 0.0001質量% ≤ B ≤ 0.0100質量%： B改良晶界強度且有助於改良韌度。為獲得此一效應，B含量較佳為0.0001質量%以上。B含量更佳為0.0005質量%以上，及進一步較佳為0.0010質量%以上。另一方面，當B含量過大時，形成大量BN且韌度劣化。因此，B含量較佳為0.0100質量%以下。B含量更佳為0.0050質量%以下，及進一步較佳為0.0030質量%以下。(15) 0.0001 mass% ≤ B ≤ 0.0100 mass%: B improves grain boundary strength and helps improve toughness. In order to obtain this effect, the B content is preferably 0.0001% by mass or more. The B content is more preferably 0.0005 mass% or more, and still more preferably 0.0010 mass% or more. On the other hand, when the B content is too large, a large amount of BN is formed and toughness deteriorates. Therefore, the B content is preferably 0.0100% by mass or less. The B content is more preferably 0.0050% by mass or less, and still more preferably 0.0030% by mass or less.

(16) 0.0001質量% ≤ Ca ≤ 0.0100質量%： Ca具有細化碳化物或氧化物及細化晶粒的作用，其有助於改良韌度。為獲得此一效應，Ca含量較佳為0.0001質量%以上。另一方面，當Ca含量過大時，熱加工性劣化。因此，Ca含量較佳為0.0100質量%以下。Ca含量更佳為0.0050質量%以下。(16) 0.0001 mass% ≤ Ca ≤ 0.0100 mass%: Ca has the effect of refining carbides or oxides and refining crystal grains, which helps to improve toughness. In order to obtain this effect, the Ca content is preferably 0.0001% by mass or more. On the other hand, when the Ca content is too large, hot workability deteriorates. Therefore, the Ca content is preferably 0.0100% by mass or less. The Ca content is more preferably 0.0050% by mass or less.

(17) 0.0001質量% ≤ Mg ≤ 0.0100質量%： Mg具有細化碳化物或氧化物及細化晶粒的作用，其有助於改良韌度。為獲得此一效應，Mg含量較佳為0.0001質量%以上。另一方面，當Mg含量過大時，熱加工性劣化。因此，Mg含量較佳為0.0100質量%以下。Mg含量更佳為0.0050質量%以下。(17) 0.0001 mass% ≤ Mg ≤ 0.0100 mass%: Mg has the effect of refining carbides or oxides and refining grains, which helps to improve toughness. In order to obtain this effect, the Mg content is preferably 0.0001% by mass or more. On the other hand, when the Mg content is too large, hot workability deteriorates. Therefore, the Mg content is preferably 0.0100% by mass or less. The Mg content is more preferably 0.0050% by mass or less.

(18) 0.001質量% ≤ Zr ≤ 0.050質量%： Zr具有細化碳化物或氧化物及細化晶粒的作用，其有助於改良韌度。為獲得此一效應，Zr含量較佳為0.001質量%以上。另一方面，當Zr含量過大時，熱加工性劣化。因此，Zr含量較佳為0.050質量%以下。Zr含量更佳為0.030質量%以下。(18) 0.001 mass% ≤ Zr ≤ 0.050 mass%: Zr has the effect of refining carbides or oxides and refining crystal grains, which helps to improve toughness. In order to obtain this effect, the Zr content is preferably 0.001% by mass or more. On the other hand, when the Zr content is too large, hot workability deteriorates. Therefore, the Zr content is preferably 0.050% by mass or less. The Zr content is more preferably 0.030% by mass or less.

(19) 0.001質量% ≤ REM ≤ 0.050質量%： REM(稀土金屬)具有細化碳化物或氧化物及細化晶粒的作用，其有助於改良韌度。為獲得此一效應，REM含量較佳為0.001質量%以上。另一方面，當REM含量過大時，熱加工性劣化。因此，REM含量較佳為0.050質量%以下。REM含量更佳為0.030質量%以下。(19) 0.001 mass% ≤ REM ≤ 0.050 mass%: REM (rare earth metal) has the effect of refining carbides or oxides and refining grains, which helps to improve toughness. In order to obtain this effect, the REM content is preferably 0.001% by mass or more. On the other hand, when the REM content is too large, the hot workability deteriorates. Therefore, the REM content is preferably 0.050% by mass or less. The REM content is more preferably 0.030% by mass or less.

[1.3. 特性] [1.3.1. 0.2%保證應力] 當將組分最佳化且進行適當熱處理時，根據本發明之沉澱硬化麻田散鐵系不鏽鋼展現相當高的0.2%保證應力。明確言之，當將組分及熱處理條件最佳化時，於室溫下的0.2%保證應力達到1,300 MPa以上。當將組分及熱處理條件進一步最佳化時，於室溫下的0.2%保證應力達到1,400 MPa以上。[1.3. Features] [1.3.1. 0.2% guaranteed stress] When the composition is optimized and appropriate heat treatment is performed, the precipitation hardening Asada scattered iron-based stainless steel according to the present invention exhibits a relatively high 0.2% guaranteed stress. Specifically, when the composition and heat treatment conditions are optimized, 0.2% at room temperature guarantees a stress of 1,300 MPa or more. When the composition and heat treatment conditions are further optimized, 0.2% at room temperature ensures that the stress reaches 1,400 MPa or more.

[1.3.2. 吸收能量] 當將組分最佳化且進行適當熱處理時，根據本發明之沉澱硬化麻田散鐵系不鏽鋼展現相當高的吸收能量。明確言之，當將組分及熱處理條件最佳化時，於室溫下的吸收能量達到30 J以上。當將組分及熱處理條件進一步最佳化時，於室溫下的吸收能量達到50 J以上。此外，當將組分及熱處理條件最佳化時，於-40℃下的吸收能量達到10 J以上。當將組分及熱處理條件進一步最佳化時，於-40℃下的吸收能量達到20 J以上。[1.3.2. Absorb energy] When the composition is optimized and appropriate heat treatment is performed, the precipitation hardening Asada scattered iron-based stainless steel according to the present invention exhibits a relatively high absorption energy. Specifically, when the composition and heat treatment conditions are optimized, the absorbed energy at room temperature reaches 30 J or more. When the composition and heat treatment conditions are further optimized, the absorbed energy at room temperature will reach more than 50 J. In addition, when the composition and heat treatment conditions are optimized, the absorbed energy at -40°C can reach more than 10 J. When the composition and heat treatment conditions are further optimized, the absorbed energy at -40°C will reach more than 20 J.

[2. 用來製造沉澱硬化麻田散鐵系不鏽鋼的方法] 根據本發明之沉澱硬化麻田散鐵系不鏽鋼可經由以下方法製造 (a) 熔融及鑄造經組合成具有預定組成的原料以獲得鑄錠， (b) 對所獲得之鑄錠進行均質化熱處理， (c) 於均質化熱處理後熱鍛材料， (d) 對經熱鍛的材料進行固溶體熱處理， (e) 視需要對固溶體熱處理後的材料進行深冷處理，及 (f) 對固溶體熱處理後或深冷處理後的材料進行時效處理。[2. The method used to manufacture precipitation hardening Matian loose iron series stainless steel] The precipitation hardening Asada scattered iron stainless steel according to the present invention can be manufactured by the following method (a) Melting and casting are combined into raw materials with a predetermined composition to obtain ingots, (b) Homogenizing heat treatment of the obtained ingot, (c) Hot-forged materials after homogenization heat treatment, (d) Solid solution heat treatment of hot forged materials, (e) Cryogenic treatment of the material after solid solution heat treatment as necessary, and (f) Aging treatment for materials after solid solution heat treatment or cryogenic treatment.

[2.1. 熔融及鑄造步驟] 首先，將經組合成具有預定組成的原料熔融及鑄造以獲得鑄錠。熔融及鑄造之方法及條件並無特定限制，且可根據目的選擇最佳方法及條件。[2.1. Melting and casting steps] First, the combined raw materials having a predetermined composition are melted and cast to obtain an ingot. There are no specific restrictions on the melting and casting methods and conditions, and the best method and conditions can be selected according to the purpose.

[2.2. 均質化熱處理步驟] 接下來，對所獲得的鑄錠進行均質化熱處理。進行均質化熱處理的目的係為了移除於鑄造期間產生的偏析。均質化熱處理之條件並無特定限制，只要達成此一效應即可。一般而言，均質化熱處理係經由將鑄錠在1,150℃至1,240℃之溫度條件下加熱及保持10小時以上來進行。[2.2. Homogenization heat treatment step] Next, homogenization heat treatment is performed on the obtained ingot. The purpose of homogenizing heat treatment is to remove segregation generated during casting. There is no specific restriction on the conditions of the homogenization heat treatment, as long as this effect is achieved. Generally speaking, the homogenization heat treatment is performed by heating and holding an ingot under a temperature condition of 1,150°C to 1,240°C for more than 10 hours.

[2.3. 熱鍛步驟] 接下來，將於均質化熱處理後的材料熱鍛。進行熱鍛的目的係為了破壞粗鑄造結構以細化結構。熱鍛的條件並無特定限制，只要達成此一效應即可。一般而言，熱鍛係經由將材料在700℃至1,240℃之條件下加熱1小時以上，將材料於700℃至1,300℃之鍛造溫度條件下鍛造，然後空氣冷卻材料來進行。熱鍛可於進行均質化熱處理後，不使材料冷卻至室溫來連續地進行。[2.3. Hot forging step] Next, the material after the homogenization heat treatment is hot forged. The purpose of hot forging is to destroy the rough cast structure to refine the structure. There is no specific restriction on the conditions of hot forging, as long as this effect is achieved. Generally speaking, hot forging is performed by heating the material at 700°C to 1,240°C for more than 1 hour, forging the material at a forging temperature of 700°C to 1,300°C, and then air cooling the material. Hot forging can be performed continuously without cooling the material to room temperature after the homogenization heat treatment.

[2.4. 固溶體熱處理步驟] 接下來，對熱鍛後的材料進行固溶體熱處理。進行固溶體熱處理的目的係為了將材料轉變為沃斯田鐵單一相然後再將材料轉變為麻田散鐵。固溶體熱處理的條件並無特定限制，只要達成此一效應即可。一般而言，固溶體熱處理係經由將材料於800℃至1,200℃之溫度條件下加熱1小時至10小時及冷卻材料來進行。冷卻方法的實例包括空氣冷卻、噴氣冷卻、油冷卻、及水冷卻。[2.4. Solid solution heat treatment steps] Next, solid solution heat treatment is performed on the material after hot forging. The purpose of the solid solution heat treatment is to transform the material into a single phase of austenitic iron and then transform the material into scattered iron. The conditions of the solid solution heat treatment are not particularly limited, as long as this effect is achieved. Generally speaking, the solid solution heat treatment is performed by heating the material at a temperature of 800°C to 1,200°C for 1 hour to 10 hours and cooling the material. Examples of cooling methods include air cooling, jet cooling, oil cooling, and water cooling.

[2.5. 深冷處理步驟] 視需要對固溶體熱處理後的材料進行深冷處理。進行深冷處理的目的係為了將固溶體熱處理後殘留的沃斯田鐵轉變為麻田散鐵。深冷處理的條件並無特定限制，只要達成此一效應即可。一般而言，深冷處理係經由將材料在0℃以下之溫度下維持1小時至10小時來進行。[2.5. Cryogenic treatment steps] If necessary, cryogenic treatment is performed on the material after the solid solution heat treatment. The purpose of the cryogenic treatment is to convert the austenitic iron remaining after the solid solution heat treatment into Asada loose iron. There are no specific restrictions on the conditions of cryogenic treatment, as long as this effect is achieved. Generally speaking, the cryogenic treatment is carried out by maintaining the material at a temperature below 0°C for 1 hour to 10 hours.

[2.6. 時效處理步驟] 接下來，對固溶體熱處理後或深冷處理後的材料進行時效處理。進行時效處理的目的係為了使基質相中諸如B2相或η相之金屬間化合物相沉澱。時效處理的條件並無特定限制，只要達成此一效應即可。一般而言，時效處理係經由將材料於400℃至600℃下加熱1小時至24小時來進行。於熱處理後，經由空氣冷卻來進行冷卻。[2.6. Aging treatment steps] Next, the material after solid solution heat treatment or cryogenic treatment is subjected to aging treatment. The purpose of the aging treatment is to precipitate the intermetallic compound phase such as the B2 phase or the η phase in the matrix phase. There is no specific restriction on the conditions of aging treatment, as long as this effect is achieved. Generally speaking, the aging treatment is performed by heating the material at 400°C to 600°C for 1 hour to 24 hours. After the heat treatment, it is cooled by air cooling.

[3. 作用] 沉澱硬化麻田散鐵系不鏽鋼於室溫下具有優異韌度，但同時，亦具有於低溫下脆化的特性。因此，習知之沉澱硬化麻田散鐵系不鏽鋼難以同時滿足在室溫下之0.2%保證應力為1,300 MPa以上、於室溫下之吸收能量係30 J以上、及於低溫(-40℃)下之吸收能量係10 J以上的條件。因此，一般而言，通常將在低溫下具有優異韌度之沃斯田鐵系不鏽鋼使用作為用於低溫環境中之元件。然而，與沉澱硬化麻田散鐵系不鏽鋼相比，沃斯田鐵系不銹鋼於室溫下的強度及韌度較差，及因此限制設計。[3. Role] Precipitation hardening Matian scattered iron stainless steel has excellent toughness at room temperature, but at the same time, it also has the characteristics of embrittlement at low temperature. Therefore, it is difficult for the conventional precipitation hardening Matian scattered iron stainless steels to simultaneously meet the 0.2% guaranteed stress at room temperature of 1,300 MPa or more, the absorbed energy at room temperature of 30 J or more, and the low temperature (-40°C) The absorbed energy is 10 J or more. Therefore, generally speaking, austenitic stainless steel with excellent toughness at low temperature is usually used as a component used in a low temperature environment. However, compared with precipitation-hardened Matian bulk iron-based stainless steel, austenitic iron-based stainless steel has inferior strength and toughness at room temperature, which limits the design.

相對地，在習知之沉澱硬化麻田散鐵系不鏽鋼中，鮮少使用Nb作為強化元素。此係由於當添加Nb時，易產生有害相。然而，當向沉澱硬化麻田散鐵系不鏽鋼添加適量Nb作為強化元素及於適當條件下進行熱處理時，於室溫下展現高強度及高韌度，及即使於低溫下亦展現高韌度。當添加適量Nb及於適當條件下進行熱處理時，Ni₃ Nb於基質相中沉澱。據認為在低溫下高韌度之表現與沉澱Ni₃ Nb晶粒之形狀及Ni₃ Nb晶粒與基質相之間的一致性相關。In contrast, Nb is rarely used as a strengthening element in the conventional precipitation hardening Asada scattered iron stainless steel. This is because when Nb is added, harmful phases are easily generated. However, when an appropriate amount of Nb is added as a strengthening element to the precipitation hardening Asada scattered iron-based stainless steel and heat-treated under appropriate conditions, it exhibits high strength and high toughness at room temperature, and high toughness even at low temperatures. When an appropriate amount of Nb is added and heat treatment is performed under appropriate conditions, Ni ₃ Nb precipitates in the matrix phase. It is believed that the performance of high toughness at low temperatures is related to the shape of the _{precipitated Ni 3} _{Nb crystal grains and the consistency between the Ni 3} Nb crystal grains and the matrix phase.

此外，當除了Nb之外複合地添加Al及／或Ti時，於室溫下之強度及韌度及於低溫下之韌度進一步地改良。當除了Nb之外添加Co時，於室溫下的強度及韌度可進一步地改良。據認為此係由於經由添加Co促進強化相的沉澱。因此，根據本發明之沉澱硬化麻田散鐵系不鏽鋼可同時滿足下列： (a) 0.2%保證應力(於室溫下) ≥ 1,300 MPa， (b) 吸收能量(於室溫下) ≥ 30 J，及 (c) 吸收能量(於-40℃下) ≥ 10 J。 [實施例]In addition, when Al and/or Ti are compounded in addition to Nb, the strength and toughness at room temperature and the toughness at low temperature are further improved. When Co is added in addition to Nb, the strength and toughness at room temperature can be further improved. It is believed that this is due to the promotion of the precipitation of the strengthening phase through the addition of Co. Therefore, the precipitation hardening Matian scattered iron stainless steel according to the present invention can simultaneously satisfy the following: (a) 0.2% guaranteed stress (at room temperature) ≥ 1,300 MPa, (b) Absorbed energy (at room temperature) ≥ 30 J, and (c) Absorbed energy (at -40℃) ≥ 10 J. [Example]

(實施例1至36及比較例1至10) [1. 製造樣本] 在真空感應爐中熔融50 kg具有表1、2及3中顯示之各別組成的鋼並鑄造成鑄錠。其後，在1,200℃之條件下對鑄錠進行均質化熱處理24小時並空氣冷卻。此外，在1,200℃之起始溫度及900℃之終止溫度的條件下鍛造具有24 mm直徑的圓桿，隨後空氣冷卻。接下來，使各鋼鑄錠經歷在1000℃之條件下的固溶體熱處理1小時並水冷卻。隨後，在-76℃之條件下進行深冷處理6小時。此外，在530℃之條件下進行時效處理4小時並空氣冷卻。(Examples 1 to 36 and Comparative Examples 1 to 10) [1. Manufacturing samples] In a vacuum induction furnace, 50 kg of steel with the respective compositions shown in Tables 1, 2 and 3 were melted and cast into ingots. Thereafter, the ingot was subjected to homogenization heat treatment at 1,200°C for 24 hours and air-cooled. In addition, a round rod with a diameter of 24 mm was forged under the conditions of an initial temperature of 1,200°C and an end temperature of 900°C, followed by air cooling. Next, each steel ingot was subjected to a solid solution heat treatment at 1000° C. for 1 hour and water-cooled. Subsequently, cryogenic treatment was carried out at -76°C for 6 hours. In addition, the aging treatment was carried out at 530°C for 4 hours and air-cooled.

[表1] 組分 (質量%) C Si Mn P S Ni Cr N Al Ti Nb Cu Fe Mo 其他實施例1 0.011 0.02 0.03 0.005 0.003 10.8 9.3 0.005 ＜ 0.01 ＜ 0.01 1.59 0.02 bal. 1.1 - 實施例2 0.005 0.03 0.08 0.006 0.004 11.0 8.6 0.005 ＜ 0.01 0.80 0.71 ＜ 0.01 bal. 1.0 - 實施例3 0.004 0.01 0.03 0.005 0.003 11.3 9.2 0.008 ＜ 0.01 1.06 0.62 0.02 bal. 0.5 - 實施例4 0.007 0.03 0.04 0.007 0.003 11.2 9.0 0.005 0.81 ＜ 0.01 0.83 0.01 bal. 1.5 - 實施例5 0.005 0.03 0.03 0.009 0.003 11.9 9.1 0.004 1.19 ＜ 0.01 0.62 0.01 bal. 1.1 - 實施例6 0.008 0.04 0.02 0.005 0.004 12.3 9.1 0.005 0.45 0.51 0.73 0.02 bal. 1.4 - 實施例7 0.007 0.02 0.12 0.006 0.003 11.0 8.9 0.010 ＜ 0.01 0.75 1.22 ＜ 0.01 bal. 1.2 - 實施例8 0.009 0.03 0.03 0.005 0.005 11.6 9.2 0.006 0.80 ＜ 0.01 1.21 0.02 bal. 1.1 - 實施例9 0.050 0.04 0.05 0.007 0.004 11.5 9.5 0.008 1.18 ＜ 0.01 0.61 0.01 bal. - - 實施例10 0.005 0.04 0.03 0.005 0.002 11.8 9.1 0.005 1.11 ＜ 0.01 0.65 0.01 bal. - W:1.6 實施例11 0.004 0.03 0.03 0.005 0.003 11.7 9.0 0.004 1.15 ＜ 0.01 0.64 0.01 bal. 0.4 W: 0.8 實施例12 0.009 0.03 0.05 0.003 0.004 10.5 9.7 0.004 0.02 0.85 0.64 0.02 bal. 0.8 Co: 3.12 實施例13 0.007 0.03 0.02 0.005 0.005 11.5 9.0 0.006 1.11 ＜ 0.01 0.66 0.01 bal. 1.2 Co: 8.20 實施例14 0.007 0.05 0.04 0.004 0.003 12.1 9.2 0.005 0.81 ＜ 0.01 0.65 0.01 bal. 1.2 V: 0.91 實施例15 0.006 0.03 0.02 0.004 0.005 12.0 9.4 0.005 0.78 ＜ 0.01 0.61 0.01 bal. 1.0 Ta: 0.46 實施例16 0.005 0.04 0.04 0.006 0.003 11.8 9.1 0.005 1.13 ＜ 0.01 0.64 0.02 bal. 1.2 B: 0.0022 實施例17 0.006 0.03 0.02 0.004 0.003 11.5 9.6 0.006 1.09 ＜ 0.01 0.58 0.01 bal. 1.3 B: 0.0068 實施例18 0.005 0.03 0.03 0.005 0.004 11.3 9.5 0.005 1.13 ＜ 0.01 0.67 0.01 bal. 1.2 Ca: 0.0055 [Table 1] Composition (mass%) C Si Mn P S Ni Cr N Al Ti Nb Cu Fe Mo other Example 1 0.011 0.02 0.03 0.005 0.003 10.8 9.3 0.005 ＜0.01 ＜0.01 1.59 0.02 bal. 1.1 - Example 2 0.005 0.03 0.08 0.006 0.004 11.0 8.6 0.005 ＜0.01 0.80 0.71 ＜0.01 bal. 1.0 - Example 3 0.004 0.01 0.03 0.005 0.003 11.3 9.2 0.008 ＜0.01 1.06 0.62 0.02 bal. 0.5 - Example 4 0.007 0.03 0.04 0.007 0.003 11.2 9.0 0.005 0.81 ＜0.01 0.83 0.01 bal. 1.5 - Example 5 0.005 0.03 0.03 0.009 0.003 11.9 9.1 0.004 1.19 ＜0.01 0.62 0.01 bal. 1.1 - Example 6 0.008 0.04 0.02 0.005 0.004 12.3 9.1 0.005 0.45 0.51 0.73 0.02 bal. 1.4 - Example 7 0.007 0.02 0.12 0.006 0.003 11.0 8.9 0.010 ＜0.01 0.75 1.22 ＜0.01 bal. 1.2 - Example 8 0.009 0.03 0.03 0.005 0.005 11.6 9.2 0.006 0.80 ＜0.01 1.21 0.02 bal. 1.1 - Example 9 0.050 0.04 0.05 0.007 0.004 11.5 9.5 0.008 1.18 ＜0.01 0.61 0.01 bal. - - Example 10 0.005 0.04 0.03 0.005 0.002 11.8 9.1 0.005 1.11 ＜0.01 0.65 0.01 bal. - W: 1.6 Example 11 0.004 0.03 0.03 0.005 0.003 11.7 9.0 0.004 1.15 ＜0.01 0.64 0.01 bal. 0.4 W: 0.8 Example 12 0.009 0.03 0.05 0.003 0.004 10.5 9.7 0.004 0.02 0.85 0.64 0.02 bal. 0.8 Co: 3.12 Example 13 0.007 0.03 0.02 0.005 0.005 11.5 9.0 0.006 1.11 ＜0.01 0.66 0.01 bal. 1.2 Co: 8.20 Example 14 0.007 0.05 0.04 0.004 0.003 12.1 9.2 0.005 0.81 ＜0.01 0.65 0.01 bal. 1.2 V: 0.91 Example 15 0.006 0.03 0.02 0.004 0.005 12.0 9.4 0.005 0.78 ＜0.01 0.61 0.01 bal. 1.0 Ta: 0.46 Example 16 0.005 0.04 0.04 0.006 0.003 11.8 9.1 0.005 1.13 ＜0.01 0.64 0.02 bal. 1.2 B: 0.0022 Example 17 0.006 0.03 0.02 0.004 0.003 11.5 9.6 0.006 1.09 ＜0.01 0.58 0.01 bal. 1.3 B: 0.0068 Example 18 0.005 0.03 0.03 0.005 0.004 11.3 9.5 0.005 1.13 ＜0.01 0.67 0.01 bal. 1.2 Ca: 0.0055

[表2] 組分 (質量%) C Si Mn P S Ni Cr N Al Ti Nb Cu Fe Mo 其他實施例 19 0.009 0.04 0.02 0.004 0.006 11.2 9.4 0.004 1.13 ＜ 0.01 0.65 0.01 bal. 1.2 Mg: 0.0053 實施例 20 0.010 0.03 0.02 0.005 0.005 11.7 9.5 0.005 1.23 ＜ 0.01 0.71 0.02 bal. 1.2 Zr: 0.017 實施例 21 0.006 0.04 0.03 0.005 0.004 12.1 9.2 0.007 1.08 ＜ 0.01 0.65 ＜ 0.01 bal. 1.1 REM: 0.009 實施例 22 0.005 0.03 0.02 0.005 0.004 9.1 11.5 0.003 1.22 ＜ 0.01 0.63 ＜ 0.01 bal. 1.5 - 實施例 23 0.003 0.03 0.03 0.005 0.003 9.3 11.3 0.004 1.15 ＜ 0.01 0.65 0.01 bal. 1.4 Co: 7.22 實施例 24 0.011 0.04 0.02 0.005 0.003 13.1 9.2 0.005 0.01 0.84 0.58 0.02 bal. 1.0 - 實施例 25 0.003 0.05 0.05 0.006 0.002 13.5 8.8 0.006 1.09 ＜ 0.01 0.67 0.03 bal. 0.9 - 實施例 26 0.008 0.02 0.03 0.003 0.002 8.3 13.3 0.004 ＜ 0.01 0.96 0.65 0.02 bal. 2.2 - 實施例 27 0.005 0.03 0.03 0.005 0.003 8.8 12.7 0.005 1.11 ＜ 0.01 0.61 ＜ 0.01 bal. 1.9 - 實施例 28 0.006 0.04 0.05 0.006 0.004 12.2 8.9 0.008 1.44 ＜ 0.01 0.62 0.03 bal. 1.1 - 實施例 29 0.007 0.05 0.07 0.004 0.003 12.4 9.1 0.009 1.81 ＜ 0.01 0.58 0.01 bal. 1.0 - 實施例 30 0.004 0.04 0.03 0.005 0.006 11.8 9.0 0.008 0.75 ＜ 0.01 0.73 0.02 bal. 1.1 - 實施例 31 0.005 0.04 0.05 0.005 0.004 12.3 9.1 0.006 0.01 1.21 0.64 0.01 bal. 0.9 - 實施例 32 0.008 0.04 0.06 0.007 0.005 12.3 9.0 0.008 0.71 0.28 0.61 0.01 bal. 1.0 - 實施例 33 0.005 0.04 0.07 0.005 0.004 12.3 9.0 0.006 1.21 0.25 0.58 0.01 bal. 1.0 - 實施例 34 0.007 0.05 0.06 0.005 0.005 12.1 8.9 0.007 0.31 0.93 0.60 0.02 bal. 1.1 - 實施例 35 0.009 0.12 0.31 0.024 0.003 11.9 9.1 0.015 1.18 ＜ 0.01 0.61 0.21 bal. 1.1 - 實施例 36 0.009 0.09 0.29 0.021 0.003 11.8 9.1 0.013 0.72 ＜ 0.01 0.61 0.15 bal. 1.0 - [Table 2] Composition (mass%) C Si Mn P S Ni Cr N Al Ti Nb Cu Fe Mo other Example 19 0.009 0.04 0.02 0.004 0.006 11.2 9.4 0.004 1.13 ＜0.01 0.65 0.01 bal. 1.2 Mg: 0.0053 Example 20 0.010 0.03 0.02 0.005 0.005 11.7 9.5 0.005 1.23 ＜0.01 0.71 0.02 bal. 1.2 Zr: 0.017 Example 21 0.006 0.04 0.03 0.005 0.004 12.1 9.2 0.007 1.08 ＜0.01 0.65 ＜0.01 bal. 1.1 REM: 0.009 Example 22 0.005 0.03 0.02 0.005 0.004 9.1 11.5 0.003 1.22 ＜0.01 0.63 ＜0.01 bal. 1.5 - Example 23 0.003 0.03 0.03 0.005 0.003 9.3 11.3 0.004 1.15 ＜0.01 0.65 0.01 bal. 1.4 Co: 7.22 Example 24 0.011 0.04 0.02 0.005 0.003 13.1 9.2 0.005 0.01 0.84 0.58 0.02 bal. 1.0 - Example 25 0.003 0.05 0.05 0.006 0.002 13.5 8.8 0.006 1.09 ＜0.01 0.67 0.03 bal. 0.9 - Example 26 0.008 0.02 0.03 0.003 0.002 8.3 13.3 0.004 ＜0.01 0.96 0.65 0.02 bal. 2.2 - Example 27 0.005 0.03 0.03 0.005 0.003 8.8 12.7 0.005 1.11 ＜0.01 0.61 ＜0.01 bal. 1.9 - Example 28 0.006 0.04 0.05 0.006 0.004 12.2 8.9 0.008 1.44 ＜0.01 0.62 0.03 bal. 1.1 - Example 29 0.007 0.05 0.07 0.004 0.003 12.4 9.1 0.009 1.81 ＜0.01 0.58 0.01 bal. 1.0 - Example 30 0.004 0.04 0.03 0.005 0.006 11.8 9.0 0.008 0.75 ＜0.01 0.73 0.02 bal. 1.1 - Example 31 0.005 0.04 0.05 0.005 0.004 12.3 9.1 0.006 0.01 1.21 0.64 0.01 bal. 0.9 - Example 32 0.008 0.04 0.06 0.007 0.005 12.3 9.0 0.008 0.71 0.28 0.61 0.01 bal. 1.0 - Example 33 0.005 0.04 0.07 0.005 0.004 12.3 9.0 0.006 1.21 0.25 0.58 0.01 bal. 1.0 - Example 34 0.007 0.05 0.06 0.005 0.005 12.1 8.9 0.007 0.31 0.93 0.60 0.02 bal. 1.1 - Example 35 0.009 0.12 0.31 0.024 0.003 11.9 9.1 0.015 1.18 ＜0.01 0.61 0.21 bal. 1.1 - Example 36 0.009 0.09 0.29 0.021 0.003 11.8 9.1 0.013 0.72 ＜0.01 0.61 0.15 bal. 1.0 -

[表3] 組分 (質量%) C Si Mn P S Ni Cr N Al Ti Nb Cu Fe Mo 其他比較例 1 0.006 0.24 0.04 0.006 0.003 10.6 9.5 0.006 0.52 0.40 0.67 0.03 bal. 1.0 - 比較例 2 0.005 0.05 0.03 0.006 0.004 7.5 9.3 0.008 0.45 0.45 0.72 0.03 bal. 1.0 - 比較例 3 0.008 0.04 0.03 0.007 0.004 15.7 9.5 0.010 0.43 0.43 0.68 0.02 bal. 1.4 - 比較例 4 0.006 0.04 0.04 0.006 0.003 11.0 7.4 0.008 0.56 0.50 0.64 0.03 bal. 1.3 - 比較例 5 0.006 0.05 0.02 0.005 0.005 11.1 14.9 0.009 0.45 0.52 0.71 0.02 bal. 1.1 - 比較例 6 0.007 0.05 0.01 0.006 0.008 11.5 9.1 0.008 0.44 0.55 0.73 0.02 bal. 3.3 - 比較例 7 0.001 0.03 0.04 0.006 0.006 10.9 9.3 0.007 2.54 0.42 0.78 0.02 bal. 1.2 - 比較例 8 0.010 0.05 0.04 0.004 0.004 11.2 9.2 0.005 0.46 1.54 0.65 0.03 bal. 1.1 - 比較例 9 0.004 0.04 0.03 0.006 0.005 11.3 9.5 0.007 0.65 0.62 0.30 0.02 bal. 1.1 - 比較例 10 0.005 0.04 0.04 0.005 0.006 11.3 9.2 0.005 0.51 0.54 2.83 0.02 bal. 1.2 - [table 3] Composition (mass%) C Si Mn P S Ni Cr N Al Ti Nb Cu Fe Mo other Comparative example 1 0.006 0.24 0.04 0.006 0.003 10.6 9.5 0.006 0.52 0.40 0.67 0.03 bal. 1.0 - Comparative example 2 0.005 0.05 0.03 0.006 0.004 7.5 9.3 0.008 0.45 0.45 0.72 0.03 bal. 1.0 - Comparative example 3 0.008 0.04 0.03 0.007 0.004 15.7 9.5 0.010 0.43 0.43 0.68 0.02 bal. 1.4 - Comparative example 4 0.006 0.04 0.04 0.006 0.003 11.0 7.4 0.008 0.56 0.50 0.64 0.03 bal. 1.3 - Comparative example 5 0.006 0.05 0.02 0.005 0.005 11.1 14.9 0.009 0.45 0.52 0.71 0.02 bal. 1.1 - Comparative example 6 0.007 0.05 0.01 0.006 0.008 11.5 9.1 0.008 0.44 0.55 0.73 0.02 bal. 3.3 - Comparative example 7 0.001 0.03 0.04 0.006 0.006 10.9 9.3 0.007 2.54 0.42 0.78 0.02 bal. 1.2 - Comparative example 8 0.010 0.05 0.04 0.004 0.004 11.2 9.2 0.005 0.46 1.54 0.65 0.03 bal. 1.1 - Comparative example 9 0.004 0.04 0.03 0.006 0.005 11.3 9.5 0.007 0.65 0.62 0.30 0.02 bal. 1.1 - Comparative example 10 0.005 0.04 0.04 0.005 0.006 11.3 9.2 0.005 0.51 0.54 2.83 0.02 bal. 1.2 -

[2. 試驗方法] [2.1. 拉伸試驗 (0.2%保證應力之測量)] 根據明確說明於ASTM A370中之金屬拉伸試驗方法進行拉伸試驗以測量0.2%保證應力。將試驗溫度設定為室溫。 [2.2. 夏比(Charpy)衝擊試驗] 收集2mm-V型缺口試件，使得縱向方向與鍛造中的延伸方向一致。根據ASTM A370標準使用試件來測量衝擊特性(吸收能量)。將試驗溫度設定為室溫或-40℃。[2. Test method] [2.1. Tensile test (0.2% guaranteed stress measurement)] The tensile test is carried out according to the metal tensile test method specified in ASTM A370 to measure the 0.2% guaranteed stress. Set the test temperature to room temperature. [2.2. Charpy impact test] Collect 2mm-V-notch test pieces so that the longitudinal direction is consistent with the extension direction during forging. The test piece is used to measure the impact characteristics (absorbed energy) according to the ASTM A370 standard. Set the test temperature to room temperature or -40°C.

[3. 結果] 結果顯示於表4及5中。自結果可看出下列事項。關於表4及5中之0.2%保證應力(@ RT)，「A」表示於室溫下的0.2%保證應力為1,400 MPa以上，「B」表示0.2%保證應力為1,300 MPa以上且低於1400 MPa，及「C」表示0.2%保證應力低於1,300 MPa。此外，關於吸收能量(@ RT)，「A」表示室溫下的吸收能量為60 J以上，「B」表示室溫下的吸收能量為40 J以上且低於60 J，及「C」表示室溫下的吸收能量低於40 J。關於吸收能量(@ -40℃)，「A」表示於-40℃下的吸收能量為20 J以上，「B」表示於-40℃下的吸收能量為10 J以上且低於20 J，及「C」表示於-40℃下的吸收能量低於10 J。[3. Results] The results are shown in Tables 4 and 5. The following items can be seen from the results. Regarding the 0.2% guaranteed stress (@ RT) in Tables 4 and 5, "A" means that the 0.2% guaranteed stress at room temperature is 1,400 MPa or more, and "B" means that the 0.2% guaranteed stress is 1,300 MPa or more and less than 1400 MPa, and "C" means that the 0.2% guaranteed stress is less than 1,300 MPa. In addition, regarding absorbed energy (@ RT), "A" means that the absorbed energy at room temperature is 60 J or more, "B" means that the absorbed energy at room temperature is 40 J or more and less than 60 J, and "C" means The absorbed energy at room temperature is less than 40 J. Regarding the absorbed energy (@ -40℃), "A" means that the absorbed energy at -40°C is 20 J or more, and "B" means that the absorbed energy at -40°C is 10 J or more and less than 20 J, and "C" means that the absorbed energy at -40°C is less than 10 J.

(1) 比較例1顯示於室溫及-40℃下的低吸收能量。據認為此係歸因於過高含量的Si所致。 (2) 比較例2顯示於室溫及-40℃下的低吸收能量。據認為此係歸因於低含量的Ni所致。 (3) 比較例3顯示於室溫下的低0.2%保證應力。據認為此係歸因於過高含量的Ni所致。 (4) 比較例4顯示於室溫下的低0.2%保證應力。據認為此係歸因於低含量的Cr所致。 (5) 比較例5顯示於室溫及-40℃下的低吸收能量。據認為此係歸因於過高含量的Cr所致。(1) Comparative Example 1 shows low energy absorption at room temperature and -40°C. It is believed that this is due to the excessively high content of Si. (2) Comparative Example 2 shows low energy absorption at room temperature and -40°C. It is believed that this is due to the low content of Ni. (3) Comparative Example 3 shows a 0.2% lower guaranteed stress at room temperature. It is believed that this is due to the excessively high content of Ni. (4) Comparative Example 4 shows a 0.2% lower guaranteed stress at room temperature. It is believed that this is due to the low content of Cr. (5) Comparative Example 5 shows low energy absorption at room temperature and -40°C. It is believed that this is due to the excessively high content of Cr.

(6) 比較例6顯示於室溫及-40℃下的低吸收能量。據認為此係歸因於過高含量的Mo所致。 (7) 比較例7顯示於室溫及-40℃下的低吸收能量。據認為此係歸因於過高含量的Al所致。 (8) 比較例8顯示於室溫及-40℃下的低吸收能量。據認為此係歸因於過高含量的Ti所致。 (9) 比較例9顯示於室溫及-40℃下的低吸收能量。據認為此係歸因於低含量的Nb所致。 (10) 比較例10顯示於室溫及-40℃下的低吸收能量。據認為此係歸因於過高含量的Nb所致。(6) Comparative Example 6 shows low energy absorption at room temperature and -40°C. It is believed that this is due to the excessively high content of Mo. (7) Comparative Example 7 shows low absorption energy at room temperature and -40°C. It is believed that this is due to the excessively high content of Al. (8) Comparative Example 8 shows low energy absorption at room temperature and -40°C. It is believed that this is due to the excessively high content of Ti. (9) Comparative Example 9 shows low absorption energy at room temperature and -40°C. It is believed that this is due to the low content of Nb. (10) Comparative Example 10 shows low energy absorption at room temperature and -40°C. It is believed that this is due to the excessively high content of Nb.

(11) 實施例1至36各者顯示於室溫下之高0.2%保證應力，及於室溫及-40℃下之高吸收能量。(11) Each of Examples 1 to 36 shows high 0.2% guaranteed stress at room temperature, and high energy absorption at room temperature and -40°C.

[表4] 0.2% 保證應力 (@ RT) 吸收能量 (@ RT) 吸收能量 (@ -40°C) 實施例 1 B A A 實施例 2 A B B 實施例 3 A B B 實施例 4 A A B 實施例 5 A A A 實施例 6 A B B 實施例 7 A B B 實施例 8 A B B 實施例 9 B A B 實施例 10 A B B 實施例 11 A B B 實施例 12 A B A 實施例 13 A A A 實施例 14 A B B 實施例 15 A B B 實施例 16 A A A 實施例 17 A B B 實施例 18 A A B 實施例 19 A A B 實施例 20 A A B 實施例 21 A A B 實施例 22 A B B 實施例 23 A B A [Table 4] 0.2% guaranteed stress (@ RT) Absorb energy (@RT) Absorb energy (@ -40°C) Example 1 B A A Example 2 A B B Example 3 A B B Example 4 A A B Example 5 A A A Example 6 A B B Example 7 A B B Example 8 A B B Example 9 B A B Example 10 A B B Example 11 A B B Example 12 A B A Example 13 A A A Example 14 A B B Example 15 A B B Example 16 A A A Example 17 A B B Example 18 A A B Example 19 A A B Example 20 A A B Example 21 A A B Example 22 A B B Example 23 A B A

[表5] 0.2% 保證應力 (@ RT) 吸收能量 (@ RT) 吸收能量 (@ -40°C) 實施例24 B A A 實施例25 B A A 實施例26 B B B 實施例27 A B B 實施例28 A A A 實施例29 A B B 實施例30 A A A 實施例31 A B B 實施例32 B A B 實施例33 A B B 實施例34 A B B 實施例35 A B B 實施例36 B A B 比較例1 B C C 比較例2 A C C 比較例3 C A A 比較例4 C A A 比較例5 A C C 比較例6 A C C 比較例7 A C C 比較例8 A C C 比較例9 A C C 比較例10 A C C [table 5] 0.2% guaranteed stress (@ RT) Absorb energy (@RT) Absorb energy (@ -40°C) Example 24 B A A Example 25 B A A Example 26 B B B Example 27 A B B Example 28 A A A Example 29 A B B Example 30 A A A Example 31 A B B Example 32 B A B Example 33 A B B Example 34 A B B Example 35 A B B Example 36 B A B Comparative example 1 B C C Comparative example 2 A C C Comparative example 3 C A A Comparative example 4 C A A Comparative example 5 A C C Comparative example 6 A C C Comparative example 7 A C C Comparative example 8 A C C Comparative example 9 A C C Comparative example 10 A C C

雖然以上已詳細說明本發明之具體例，但本發明並不受限於前述具體例，且可進行各種修改而不脫離本發明之主旨。本申請案係基於2020年2月4日提出申請之日本專利申請案第2020-16838號及2020年10月22日提出申請之日本專利申請案第2020-177624號，將其內容以引用的方式併入本文。 (工業應用性)Although the specific examples of the present invention have been described in detail above, the present invention is not limited to the foregoing specific examples, and various modifications can be made without departing from the spirit of the present invention. This application is based on the Japanese Patent Application No. 2020-16838 filed on February 4, 2020 and the Japanese Patent Application No. 2020-177624 filed on October 22, 2020. The contents are incorporated by reference. Incorporated into this article. (Industrial applicability)

根據本發明之沉澱硬化麻田散鐵系不鏽鋼可用於(a)用於地下鑽孔之鑽機中之污水馬達組件的轉子及定子，其藉由流體的水力旋轉，(b)傳送轉子及定子之旋轉的驅動軸，(c)固持驅動軸之軸承的結構元件，(d)用於地下鑽孔之鑽機之隨鑽量測工具(MWD；measurement-while-drilling tools)的結構元件，其測量鑽管組(drill string)的深度、傾斜角、及方位角，(e)分析地質特徵之隨鑽測井工具(LWD；logging-while-drilling tools)的結構元件，及(f) MWD或LWD的外殼元件。此外，根據本發明之沉澱硬化麻田散鐵系不鏽鋼可用於汽輪機葉片、航空太空結構元件、高強度扣件、或其類似物。The precipitation hardening Asada scattered iron-based stainless steel according to the present invention can be used for (a) the rotor and stator of the sewage motor assembly in the drilling rig used for underground drilling, which is rotated by the hydraulic power of the fluid, and (b) transmits the rotation of the rotor and the stator (C) The structural element of the bearing that holds the drive shaft, (d) The structural element of the MWD (measurement-while-drilling tools) of the drilling rig used for underground drilling, which measures the drill pipe Group (drill string) depth, tilt angle, and azimuth angle, (e) structural elements of logging-while-drilling tools (LWD; logging-while-drilling tools) for analyzing geological features, and (f) MWD or LWD shell element. In addition, the precipitation hardening Asada bulk iron-based stainless steel according to the present invention can be used for steam turbine blades, aerospace structural elements, high-strength fasteners, or the like.

Claims

一種沉澱硬化麻田散鐵系不鏽鋼，其由以下組分組成： 0 ＜ C ＜ 0.10質量%， 0 ＜ Si ≤ 0.20質量%， 0 ＜ Mn ≤ 1.00質量%， 8.0質量% ≤ Ni ≤ 15.0質量%， 8.0質量% ≤ Cr ≤ 14.0質量%， 0.4質量% ≤ Nb ≤ 2.50質量%，及可選地， Al ≤ 2.50質量%， Ti ≤ 1.50質量%， Co ≤ 10.0質量%， Mo ≤ 3.0質量%， W ≤ 3.0質量%， V ≤ 2.0質量%， Ta ≤ 1.0質量%， B ≤ 0.0100質量%， Ca ≤ 0.0100質量%， Mg ≤ 0.0100質量%， Zr ≤ 0.050質量%，及 REM ≤ 0.050質量%，及其餘係Fe及無可避免的雜質。A precipitation hardening Matian scattered iron stainless steel, which is composed of the following components: 0 ＜ C ＜ 0.10 mass%, 0 <Si ≤ 0.20 mass%, 0 <Mn ≤ 1.00 mass%, 8.0 mass% ≤ Ni ≤ 15.0 mass%, 8.0% by mass ≤ Cr ≤ 14.0% by mass, 0.4% by mass ≤ Nb ≤ 2.50% by mass, and Optionally, Al ≤ 2.50 mass%, Ti ≤ 1.50 mass%, Co ≤ 10.0 mass%, Mo ≤ 3.0% by mass, W ≤ 3.0% by mass, V ≤ 2.0% by mass, Ta ≤ 1.0% by mass, B ≤ 0.0100 mass%, Ca ≤ 0.0100 mass%, Mg ≤ 0.0100 mass%, Zr ≤ 0.050% by mass, and REM ≤ 0.050% by mass, and The rest are Fe and inevitable impurities.

如請求項1之沉澱硬化麻田散鐵系不鏽鋼，其包含： 0.10質量% ≤ Al ≤ 2.50質量%，及／或 0.10質量% ≤ Ti ≤ 1.50質量%。For example, the precipitation hardening Matian bulk iron stainless steel of claim 1, which includes: 0.10 mass% ≤ Al ≤ 2.50 mass%, and/or 0.10 mass% ≤ Ti ≤ 1.50 mass%.

如請求項1之沉澱硬化麻田散鐵系不鏽鋼，其包含： 0.10質量% ≤ Al ≤ 2.50質量%，及 Ti ＜ 0.10質量%。For example, the precipitation hardening Matian bulk iron stainless steel of claim 1, which includes: 0.10 mass% ≤ Al ≤ 2.50 mass%, and Ti <0.10% by mass.

如請求項1之沉澱硬化麻田散鐵系不鏽鋼，其包含： 0.10質量% ≤ Co ≤ 10.0質量%。For example, the precipitation hardening Matian bulk iron stainless steel of claim 1, which includes: 0.10% by mass ≤ Co ≤ 10.0% by mass.

如請求項1之沉澱硬化麻田散鐵系不鏽鋼，其包含以下至少一者： 0.10質量% ≤ Mo ≤ 3.0質量%， 0.10質量% ≤ W ≤ 3.0質量%， 0.3質量% ≤ V ≤ 2.0質量%， 0.01質量% ≤ Ta ≤ 1.0質量%， 0.0001質量% ≤ B ≤ 0.0100質量%， 0.0001質量% ≤ Ca ≤ 0.0100質量%， 0.0001質量% ≤ Mg ≤ 0.0100質量%， 0.001質量% ≤ Zr ≤ 0.050質量%，及 0.001質量% ≤ REM ≤ 0.050質量%。For example, the precipitation hardening Matian scattered iron stainless steel of claim 1, which contains at least one of the following: 0.10 mass% ≤ Mo ≤ 3.0 mass%, 0.10 mass% ≤ W ≤ 3.0 mass%, 0.3% by mass ≤ V ≤ 2.0% by mass, 0.01% by mass ≤ Ta ≤ 1.0% by mass, 0.0001 mass% ≤ B ≤ 0.0100 mass%, 0.0001% by mass ≤ Ca ≤ 0.0100% by mass, 0.0001 mass% ≤ Mg ≤ 0.0100 mass%, 0.001% by mass ≤ Zr ≤ 0.050% by mass, and 0.001% by mass ≤ REM ≤ 0.050% by mass.

如請求項1至5中任一項之沉澱硬化麻田散鐵系不鏽鋼，其於室溫下具有1,300 MPa以上的0.2%保證應力。For example, the precipitation hardening Matian scattered iron stainless steel of any one of claims 1 to 5 has a 0.2% guaranteed stress of 1,300 MPa or more at room temperature.

如請求項1至5中任一項之沉澱硬化麻田散鐵系不鏽鋼，其於室溫下具有30 J以上的吸收能量。For example, the precipitation hardening Matian scattered iron stainless steel of any one of claims 1 to 5 has an absorbed energy of 30 J or more at room temperature.

如請求項6之沉澱硬化麻田散鐵系不鏽鋼，其於室溫下具有30 J以上的吸收能量。For example, the precipitation hardening Matian scattered iron stainless steel of claim 6 has an absorbed energy of more than 30 J at room temperature.

如請求項1至5中任一項之沉澱硬化麻田散鐵系不鏽鋼，其於-40℃下具有10 J以上的吸收能量。Such as the precipitation hardening Matian scattered iron stainless steel of any one of claims 1 to 5, which has an absorbed energy of more than 10 J at -40°C.

如請求項6之沉澱硬化麻田散鐵系不鏽鋼，其於-40℃下具有10 J以上的吸收能量。For example, the precipitation hardening Matian scattered iron stainless steel of claim 6 has an absorbed energy of more than 10 J at -40°C.

如請求項7之沉澱硬化麻田散鐵系不鏽鋼，其於-40℃下具有10 J以上的吸收能量。For example, the precipitation hardening Matian scattered iron stainless steel of claim 7 has an absorbed energy of more than 10 J at -40°C.

如請求項8之沉澱硬化麻田散鐵系不鏽鋼，其於-40℃下具有10 J以上的吸收能量。For example, the precipitation hardening Matian scattered iron stainless steel of claim 8 has an absorbed energy of more than 10 J at -40°C.