TW200946694A

TW200946694A - Ferritic stainless steel with excellent heat resistance and toughness

Info

Publication number: TW200946694A
Application number: TW098107277A
Authority: TW
Inventors: Yasushi Kato; Norimasa Hirata; Tetsuyuki Nakamura; Takumi Ujiro
Original assignee: Jfe Steel Corp
Priority date: 2008-03-07
Filing date: 2009-03-06
Publication date: 2009-11-16
Also published as: KR20130049835A; US20110123387A1; CN101965415B; EP2264202A1; KR20100105800A; ES2519716T3; CN101965415A; JP5387057B2; EP2264202A4; WO2009110641A1; JP2009235573A; EP2264202B1; BRPI0909643A2; RU2443796C1; TWI431122B

Abstract

Provided is a ferritic stainless steel having excellent thermal fatigue characteristics and oxidation resistance, without the addition of expensive elements such as molybdenum and tungsten, and having toughness equivalent to or greater than that of Type 429. Specifically, the ferritic stainless steel has, by mass: no more than 0.015% carbon, no more than 0.5% silicon, no more than 0.5% manganese, no more than 0.04% phosphorus, no more than 0.006% sulfur, no more than 16% to 20% chromium, no more than 0.015% nitrogen, between 0.3% and 0.55% niobium, no more than 0.1% titanium, no more than 0.1% molybdenum, no more than 0.1% tungsten, between 1.0% and 2.5% copper, and between 0.2% to 1.2% aluminum, with the remainder comprising iron and unavoidable impurities.

Description

200946694 六、發明說明：【發明所屬之技術領域】本發明係關於一種含Cr之鋼，尤其係關於一種適合用於汽車（automobi le)或機器腳踏車（motorcycle)之排氣管 (exhaust pipe)、轉換器外殼（converter case)或火力發電廠（thermal electric power plant)之排氣管道（exhaust air duct)等於高溫環境下所使用之排氣系統構件中，高耐 ❹熱性（耐熱疲勞特性（thermal fatigue resistance)、耐氧化性（oxidation resistance))與母材之動性（toughness) 優異之肥粒鐵系不鏽鋼（ferritic stainless steel)。【先前技術】對於汽車之排氣系統環境下所使用之排氣歧管（exhaus t manifold)、排氣管、轉換器外殼、消音器（muffier)等排氣系統構件，要求熱疲勞特性及耐氧化性（以下，將兩特性統 0 稱為「耐熱性」）均優異。針對要求此種耐熱性之用途，目前，添加有 Nb 與 Si 之例如 Type429(14Cr-0· 9Si-0. 4Nb 系）般之含有Cr之鋼被較多地使用。然而，伴隨引擎性能之提高’排氣溫度（exhaust gas temperature)會上升至如超過 • 900°C般之溫度為止’從而對於Type429而言，熱疲勞特性 - 並不充分。針對上述問題’添加有Nb與以使高溫耐力（high temperature proof stress)得到提高之含有Cr之鋼，或由 098107277 3 200946694 JIS G4305 所規定之 SUS444(19Cr-0.2Nb-1.8Mo)、添加有 Nb、Mo、W之肥粒鐵系不鏽鋼等已得到開發（例如，參照曰本專利特開2004-018921號公報）。然而，由於最近Mo或W 等稀有金屬原料之價格異常高，故而要求使用廉價之原料而開發出一種具有同等之耐熱性之材料。作為不使用尚彳貝之元素之Mo或W而耐熱性（heat resistance)優異之材料，例如，於W02003/004714號手冊中揭示有一種汽車排氣流路構件用肥粒鐵系不鏽鋼，其係於 10〜2〇11^3°/。(：1'鋼中添加了肋：〇.5〇1^53%以下、（：11:〇.8 〜2_ 0 mass%、V : 0_ 03〜0· 20 mass%而成；又，於日本專利特開2006-117985號公報中揭示了一種熱疲勞特性優異之肥粒鐵系不鏽鋼，其係於1〇〜2〇 mass%Cr鋼中添加了 Ti : 0. 05〜0. 30 mass%、Nb : 0· 1〇〜〇· 6〇 mass%、Cu : 〇 8〜2 〇 mass%、B : 0. 0005〜〇. 02 mass%而成；又，於日本專利特開 2000-297355號公報中揭示了—種汽車排氣系統零件用肥粒鐵系不鏽鋼，其係於15〜25 _齡鋼巾添加了 cu: 1 〜3maSS%而成。該些鋼之特徵均在於：藉由添加a而提高熱疲勞特性。然而，根據發明者等人之研究可知，於如上述專利文獻2 〜4之技減添加Gu讀_，雖闕減料性高’但鋼自身之耐氧化性卻降低，總體來看，耐又，SUS444 與 Type429 相比， *、、、名化。重更円，且添加有大 098107277 200946694 里之Mo，因此，存在母材之韌性劣化之問題。因此，本發明之目的在於開發出一種防止因添加。致耐氧化性降低之技術，藉此，本發明係提供一種無需添 Mo或W等高價之元素而熱疲勞特性和耐氧化性優里、同時具有與¥429同等以上之勒性之肥粒鐵系不義。此處，本發明所提及之「優異之财氧化性和耐熱疲勞特性」，係指具有與SUS444同等以上之特性，具體而言，耐氧化^ 參95G°C時之耐氧化性’又’熱疲勞特性係於⑽以阶門循環之熱疲勞特性，與腿44為同等以上。又，所㈣ .TyPe429同等之勤性，係指當以―靴對板厚為2顏之冷札 .板進行夏比衝擊（Charpy impact)試驗時之脆性破面率與 - Type429 同等。【發明内容】本發明係-種肥粒鐵系不鏽鋼’其含有c :請5嶋％〇以下、Si: 0. 5 mass%以下、Μη: 0· 5 mass%以下、p: 〇· 〇4 mass% 以下、S: 0.0()6 mass% 以下、Cr : 16 〜2〇 mass% 以下、N: 0. 015 mass%以下、Nb : 0. 3〜0. 55 mass%、Ti : 〇. 01 mass% 以下、Mo : 0.1 mass%以下、W : 〇·ι 贴沾％以下、Cu : 1〇 - 〜2. 5 mass%、A1 : 0.2〜1.2 mass%’剩餘部分由以及不可 - 避免之雜質而構成。又’本發明之肥粒鐵系不鏽鋼之特徵在於：除上述之成分組成之外’更包含自B: 0.003 mass%以下、REM: 〇〇8mass% 098107277 5 200946694 以下、Zr : 0. 5 mass%以下、v · η ς • 以下、c〇:〇.5mass0/〇以下及Ni:G.5maSS%以下之中所選H種或2種以上。根據本發明，可廉價地獲得叙與觀44同等以上之耐埶性（^泰加高價M。或W而具有生（熱疲勞特性、耐氧化性），同時具有與Type429(代表成分參昭 ^ 、/ ，、表1之鋼No. 24)同等以上之勒性之肥粒鐵系不鐵鋼。因此，汽車排氣纽構件中。本發明之鋼可較佳地用於【實施方式】發明者等人反覆進行積極 __ _ .社„ , * 九而開發出如下之肥粒鐵系不鏽鋼，/、防止先則技術所面臨 ,,... . 之由於添加Cu而引起对氧化性之降低，同時無需添加 „ w 次w等高價之元素，熱疲勞特性與魏化性優異、並且 0.3〜0.55 mass%範圍内添加恥、 ' 曰内添加Cu而於寬溫度區獲、U〜2.5廳獻範圍性得到改善，又，藉由添加G.2<高溫強度，且熱疲勞特因添加Cu所引起之耐氧化性之降以上之土1 ’而可防止及A1控制於上述適當範圍内，益/因此藉由將Nb Cu SUS444同等以上之耐添加Mo或Η更可獲得與 ^ f A1 “、、疲勞特性、耐氧化性）。進而發現添加有Cu、Al之鋼之循係藉由使Si之添加量最佳减試驗之耐鏽剝離性，祕係藉由使^^之.5_%以下）而提高’及，以下 098107277 1 ·〇· 01 mass%以下）而可與 200946694200946694 VI. Description of the Invention: [Technical Field] The present invention relates to a steel containing Cr, in particular to an exhaust pipe suitable for use in an automobile or a motorcycle. The converter case or the exhaust electric duct of the thermal electric power plant is equal to the exhaust system component used in the high temperature environment, and has high heat resistance (thermal fatigue). Resistance), oxidative resistance, and ferrite stainless steel excellent in the toughness of the base material. [Prior Art] Thermal exhaust characteristics and resistance are required for exhaust system components such as an exhaust manifold, an exhaust pipe, a converter casing, and a muffer used in an exhaust system environment of a vehicle. Oxidation properties (hereinafter, both properties are referred to as "heat resistance") are excellent. For applications requiring such heat resistance, steels containing Cr such as Type 429 (14Cr-0· 9Si-0. 4Nb) which are added with Nb and Si are used in many cases. However, with the improvement of engine performance, the "exhaust gas temperature" rises to a temperature as high as 900 °C, so that the thermal fatigue characteristics are not sufficient for Type 429. In response to the above problem, Nb is added with Cr-containing steel to improve high temperature proof stress, or SUS444 (19Cr-0.2Nb-1.8Mo) specified by 098107277 3 200946694 JIS G4305, and Nb is added. The ferrite-grained stainless steel of Mo, W, and the like have been developed (for example, refer to Japanese Laid-Open Patent Publication No. 2004-018921). However, due to the unusually high price of rare metal raw materials such as Mo or W, it is required to develop a material having the same heat resistance by using inexpensive raw materials. As a material which is excellent in heat resistance without using Mo or W which is an element of the mulberry, for example, in the manual of WO2003/004714, a ferrite-based iron-based stainless steel for an automobile exhaust flow path member is disclosed. At 10~2〇11^3°/. (:1' steel has been added with ribs: 〇.5〇1^53% or less, (:11: 〇.8 ～2_ 0 mass%, V: 0_ 03~0· 20 mass%; and, in Japan And the mass of the steel is added to the steel of the steel. The mass of the steel is added to the steel: Ti. 0. 05~0. 30 mass%, Nb: 0·1〇~〇·6〇mass%, Cu: 〇8~2 〇mass%, B: 0. 0005~〇. 02 mass%; and, in Japanese Patent Laid-Open No. 2000-297355 The invention discloses a ferrite-type iron-based stainless steel for automobile exhaust system parts, which is obtained by adding cu: 1 to 3 maSS% to a steel towel of 15 to 25 years old. The characteristics of the steels are: by adding a However, according to the research by the inventors and the like, it is known that the technique of the above-mentioned Patent Documents 2 to 4 is less than the addition of the Gu reading _, although the refractory property is high, but the oxidation resistance of the steel itself is lowered. Overall, SUS444 is compared with Type429, *,, and naming. It is more sturdy, and it adds Mo in 098107277 200946694. Therefore, there is a problem that the toughness of the base metal deteriorates. SUMMARY OF THE INVENTION An object of the present invention is to provide a technique for preventing reduction in oxidation resistance by addition, whereby the present invention provides a thermal fatigue property and oxidation resistance superiority without adding a high-priced element such as Mo or W, and at the same time ¥429 is equivalent to the above-mentioned fat ferrite. The term "excellent oxidizing and thermal fatigue resistance" as used in the present invention means having the same or higher characteristics as SUS444, specifically, resistance. The oxidation resistance of 'oxidation' at 95G °C's 'thermal fatigue' is based on (10) the thermal fatigue characteristics of the step door cycle, which is equal to or higher than the leg 44. Also, (4) TyPe429 is equivalent to the diligence. In the Charpy impact test, the brittleness rate of the plate is the same as that of - Type 429. The present invention is a type of fermented iron-based stainless steel. Contains c: Please be 5嶋% 〇 below, Si: 0. 5 mass% or less, Μη: 0· 5 mass% or less, p: 〇· 〇4 mass% or less, S: 0.0()6 mass% or less, Cr: 16 〜2〇mass% or less, N: 0. 015 mass% or less, Nb: 0. 3~0. 55 mass%, Ti : 〇. 01 mass% or less, Mo: 0.1 mass% or less, W: 〇·ι affixed below %, Cu: 1〇- ～2. 5 mass%, A1: 0.2~1.2 mass%' remaining part and not - Consist of impurities. Further, the ferrite-based iron-based stainless steel of the present invention is characterized in that: in addition to the above-described component composition, it is further contained from B: 0.003 mass% or less, REM: 〇〇8mass% 098107277 5 200946694 or less, Zr: 0.5 mass%. In the following, v · η ς • The following, c〇: 〇.5mass0/〇 or less and Ni: G.5maSS% or less, H or more. According to the present invention, it is possible to inexpensively obtain the same resistance to the above-mentioned view 44 (^Taga high price M or W and has raw (thermal fatigue characteristics, oxidation resistance), and has a type 429 (representative ingredient Steel, No. 24) Steel No. 24) of the same grade or more is not iron-iron. Therefore, in the automobile exhaust member, the steel of the present invention can be preferably used in the invention. The person and others repeatedly carried out positive __ _ . 社 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , It is not necessary to add high-priced elements such as w w w, which is excellent in thermal fatigue characteristics and Wei Wei, and adds shame in the range of 0.3 to 0.55 mass%, adding Cu in the crucible and obtaining in the wide temperature zone, U~2.5 hall The scope is improved, and by adding G.2 < high temperature strength, and the thermal fatigue is caused by the addition of Cu, the oxidation resistance is reduced by the soil 1', and A1 is prevented from being controlled within the above appropriate range. Benefit / Therefore, by adding Nb Cu SUS444 equivalent or more to add Mo or Η And ^ f A1 ", fatigue characteristics, oxidation resistance". Further found that the addition of Cu, Al steel is the best way to reduce the amount of Si to reduce the rust resistance of the test, the secret system by ^ ^.5_% or less) and improve 'and, below 098107277 1 ·〇· 01 mass% or less) and with 200946694

Type429同等以上’從而完成了本發明。首先’對開發本發明之基礎實驗進行說明。以由 C : 0. 005〜0· 007 mass%、N : 0· 004〜〇. 〇〇6 mass%、 Si . 0. 3 mass%、Μη : 0. 2 mass%，Cr : 17 mass%、Nb : 0· 45The type 429 is equal to or higher than the above, thereby completing the present invention. First, the basic experiment for developing the present invention will be described. By C: 0. 005~0· 007 mass%, N: 0· 004~〇. 〇〇6 mass%, Si. 0. 3 mass%, Μη: 0.2 mass%, Cr: 17 mass%, Nb : 0· 45

mass%及A1 : 0_ 35 mass%所構成之成分組成作為基礎，在實驗至熔製出上述成分組成中Cu之添加量有各種變化變化之鋼，形成50 kg鋼塊，加熱至ii7〇°C後，進行熱軋而形成 ❹ 厚.30 mmx寬：150 mm之薄鋼片（sheet bar)。然後，對該薄鋼片進行鍛造，形成剖面為35 mmx35丽之鋼條，以i〇30°C - 之溫度進行退火後再進行機械加工，從而製作出如圖丨所示之尺寸之熱疲勞試驗片（thermal fatigue test specimen)。繼而，使如圖2所示之、以限制率（restraint - ratio) :0.35而於1〇〇。〇-850〇C間加熱、冷卻之熱處理循環進行，從而測定出熱疲勞壽命（thermal fatigueHfe)。再 ❹者，對於上述熱疲勞壽命而言，係將i〇(TC時所檢測出之負重（load)除以圖1所示之試驗片均熱平行部之剖面積 (cross section)而算出應力（stress)，從而設為應力相對於前一循環（cycle)之應力而開始連續地降低時之最小循環數11亥循環數相當於試驗片上產生龜裂（crack)之循環數。 -再者，作為比較，對 SUS444(Cr: 18mass%-Mo: 2mass%-Nb : 0· 5 mass%鋼）亦進行相同之試驗。圖3係表不上述熱疲勞試驗之結果。根據該圖可知藉由 098107277 7 200946694 添加1. 0 mass%以上之Cu，可獲得與SUS444之熱疲勞壽命 (約1100循環）同等以上之熱疲勞壽命，因此’對於改善熱疲勞特性而言，添加1 mass%以上之Cu係有效之方法。繼而’以由 C : 0. 〇〇6 mass%、N : 〇· 〇〇7 mass%、Μη : 0· 2 mass% ' Si ： 0. 3 mass% > Cr ： 17 mass% ' Nb ： 0. 49 mass% 及Cu : 1. 5 mass%所構成之成分組成作為基礎，在實驗室熔製出上述成分組成中A1之添加量有各種變化之鋼，形成5〇 kg鋼塊，對該鋼塊進行熱軋（h〇t rolling)，對熱軋板進行退火後再進行冷軋（cold r〇ning)、精退火（finishing annealing) ’從而形成板厚為2顏之冷軋退火板。自如上所述之方式而獲得之冷軋鋼板切出30 mmx20 mm之試驗片，於該試驗片上部開有4mm φ之孔，利用# 320之砂紙（emery paper)對表面及端面進行研磨並脫脂後，提供給下述之試驗。 < 連續氧化試驗（continuous oxidation test in air) > 將上述試驗片保持於加熱至95〇。〇之大氣環境之爐中goo 小時，並對加熱試驗前後之試驗片之質量之差進行測定，而求出每單位面積之氧化增量（g/m2)。盾環氧化試驗（cyclic oxidation test in air)> 使用上述試驗片’於大氣中，使以l〇(rCxl rain及 950 Cx25 min之溫度循環加熱、冷卻之熱處理進行6Q〇循環’根據試驗前後之質量差測定出已自試驗片表面剝離之鏽 098107277 200946694 量（50316 3111011111：)(8/1112)。再者，上述試驗中之加熱速度及冷卻速度分別以5°C/sec、1. 5°C/sec而進行。圖4係表示氧化增量之測定結果。又，圖5係表示鏽剝離量之測定結果。根據該些圖可知，藉由添加0. 2 mass%以上 '之A1，可獲得與SUS444同等以上之耐氧化性（氧化增量·· 27 g/m2以下，鏽剝離量：4 g/m2未滿）。繼而，以由 C : 0. 006 mass%、N : 0. 007 mass%、Μη : 0. 2 ❹ mass%、Α1 : 0· 45 mass%、Cr : 17 mass%、Nb : 0· 49 mass%、Based on the composition of mass% and A1: 0_35 mass%, the steel with various changes in the amount of Cu added in the above composition is melted to form a 50 kg steel block and heated to ii7 〇 °C. Thereafter, hot rolling was performed to form a sheet bar having a thickness of 30 mm x 150 mm. Then, the thin steel sheet is forged to form a steel strip having a profile of 35 mm x 35 Å, annealed at a temperature of 30 ° C - and then machined to produce a thermal fatigue of the size shown in FIG. Thermal fatigue test specimen. Then, as shown in FIG. 2, the restraint-ratio is 0.35 and is 1 〇〇. The thermal fatigue Hfe was measured by a heat treatment cycle of heating and cooling between 〇-850 〇C. Further, for the above thermal fatigue life, the stress is calculated by dividing the load detected by TC by the cross section of the heat parallel portion of the test piece shown in FIG. (stress), the minimum number of cycles when the stress starts to decrease continuously with respect to the stress of the previous cycle, and the number of cycles of 11 cycles corresponds to the number of cycles in which cracks are generated on the test piece. For comparison, the same test was carried out on SUS444 (Cr: 18 mass%-Mo: 2 mass%-Nb: 0.5 mass% steel). Figure 3 shows the results of the above thermal fatigue test. According to the figure, it is known by 098107277 7 200946694 When more than 1.0 mass% of Cu is added, thermal fatigue life equal to or higher than the thermal fatigue life of SUS444 (about 1100 cycles) can be obtained. Therefore, for the improvement of thermal fatigue characteristics, more than 1 mass% of Cu is added. An effective method. Then 'C: 0. 〇〇6 mass%, N: 〇·〇〇7 mass%, Μη: 0·2 mass% ' Si : 0. 3 mass% > Cr : 17 mass% ' Nb : 0. 49 mass% and Cu : 1. 5 mass% of the composition of the composition as a basis for melting in the laboratory A steel having various changes in the amount of A1 added to the above composition is formed, and a steel block of 5 〇kg is formed, and the steel block is hot rolled (h〇t rolling), and the hot rolled sheet is annealed and then cold rolled (cold) R〇ning), finishing annealing 'to form a cold rolled annealed sheet having a thickness of 2 Å. A cold rolled steel sheet obtained as described above was cut out of a test piece of 30 mm x 20 mm, and the test piece was cut out. The upper part is opened with a hole of 4 mm φ, and the surface and the end surface are ground and degreased by using #320 emery paper, and then subjected to the following test. <continuous oxidation test in air > The test piece was kept at a temperature of 95 Torr. The hour in the atmosphere of the atmosphere was measured, and the difference in mass between the test pieces before and after the heating test was measured to determine the oxidation increment per unit area (g/m2). Cyclooxy oxidation test in air> Using the above test piece 'in the atmosphere, the heat treatment was carried out by heat treatment of rCxl rain and 950 Cx25 min, and heat treatment was carried out for 6Q〇 cycle. low quality Since the amount of the release fix has surface sheet 098 107 277 200 946 694 Rust test (503,163,111,011,111:) (8/1112). Further, the heating rate and the cooling rate in the above test were carried out at 5 ° C / sec and 1.5 ° C / sec, respectively. Fig. 4 shows the measurement results of the oxidation increment. Further, Fig. 5 shows the measurement results of the amount of rust peeling. According to these figures, it is possible to obtain an oxidation resistance equivalent to or higher than SUS444 by adding 0.2 mol% or more of A1 (oxidation increase·27 g/m2 or less, rust release amount: 4 g/m2 not full). Then, from C: 0.006 mass%, N: 0.007 mass%, Μη: 0.2 ❹ mass%, Α1: 0·45 mass%, Cr: 17 mass%, Nb: 0·49 mass% ,

Cu : 1. 5 mass%所構成之成分組成作為基礎，在實驗室熔製出上述成分組成中Si之添加量有各種變化之鋼，形成5〇 kg 鋼塊，以與上述相同方式形成板厚為2 mm之冷軋退火板， '且以與上述相同之方式進行循環氧化試驗，測定出錄剝離 - 量’並將其結果示於圖6中。據此可知，即便適量添加A1，若S i超過0· 5% ’則鑛密者性會降低而剝離量會增加，從而 ❹ 無法獲得與SUS444同等之耐熱性。最後’以由 C : 0. 006〜0. 〇〇7 mass%、N : 〇. 〇〇6〜〇〇〇7 mass%、Si : 0. 3 mass%、Cr : 17 mass%、Nb : 〇. 45 mass% 及Cu : 1· 5 mass%所構成之成分組成作為基礎，在實驗室熔 - 製出上述成分組成中Μη、A1及Ti之含量有各種變化之鋼，形成50 kg鋼塊，對該鋼塊進行熱軋後再對熱軋板進行退火、冷軋、精退火，從而形成板厚為2 mm之冷軋退火板。自e亥冷軋退火板獲取次尺寸（sub size)之夏比衝擊試驗片 098107277 9 200946694 (Charpy impact test specimen)，以-4(TC 之溫度進行夏比衝擊試驗，測定出脆性破面率，並對韌性進行評估。圖 7 係表示 A1 : 0. 25 mass%、Ti : 0. 006 mass%時之 Μη 含量對韌性所造成之影響，圖8係表示Μη: 0. 1 mass%、Ti : 0.005 mass%時之A1含量對韌性所造成之影響，又，圖9 係表示A1 : 0. 25 mass%、Μη : 0· 1 mass%時之Ti含量對勒性所造成之影響。根據該些圖可知，為了獲得與Type429 同等以上之韌性，必需為Μη: 0. 3 mass%以下、A1: 1. 2 mass% 以下、Ti : 〇. 01 mass%以下。本發明係於上述見解上進一步進行研究而完成者。繼而，對本發明之肥粒鐵系不鏽鋼之成分組成進行說明。 C : 0. 015 mass%以下 c係有效地提高鋼之強度之元素，當含有超過〇〇i5m⑽ 之C時，韌性及成形性之降低變得顯著。因此，本發明中， C設為0.015 mass%以了。再者’自確保成形性之觀點考慮， C越低越好，較理想的是0.008 mass%以下。另一方面，為了確保作為排氣系統構件之強度，c較佳為請丨上。更佳為〇· 〇〇2〜0· 〇〇8 fflass%之範圍内。Based on the composition of Cu: 1. 5 mass%, a steel having various changes in the amount of Si added in the above composition is melted in the laboratory to form a steel bar of 5 〇kg, and a plate thickness is formed in the same manner as described above. The cold rolled annealed sheet of 2 mm was subjected to a cyclic oxidation test in the same manner as above, and the peeling amount was measured and the results are shown in Fig. 6. From this, it is understood that even if A1 is added in an appropriate amount, if S i exceeds 0.5% 5%, the minerality is lowered and the amount of peeling is increased, so that heat resistance equivalent to that of SUS444 cannot be obtained. The last 'by C: 0. 006~0. 〇〇7 mass%, N: 〇. 〇〇6~〇〇〇7 mass%, Si: 0.3 mass%, Cr: 17 mass%, Nb: 〇 45 mass% and Cu: 1-5 mass% of the composition of the composition, in the laboratory melting - the composition of the above composition of Μη, A1 and Ti with varying amounts of steel, forming 50 kg of steel, After the steel block is hot rolled, the hot rolled sheet is annealed, cold rolled, and finish annealed to form a cold rolled annealed sheet having a thickness of 2 mm. A sub-size Charpy impact test specimen of 098107277 9 200946694 (Charpy impact test specimen) was obtained from the cold rolled annealed sheet, and a Charpy impact test was performed at a temperature of -4 (TC) to determine the brittle fracture rate. The toughness is evaluated. Fig. 7 shows the influence of the Μη content on the toughness when A1: 0.25 mass%, Ti: 0. 006 mass%, and Fig. 8 shows Μη: 0.1 mass%, Ti: The effect of the A1 content on the toughness at 0.005 mass%, and Figure 9 shows the effect of the Ti content on the characterization of A1: 0.25 mass%, Μη: 0·1 mass%. As shown in the figure, in order to obtain the toughness equivalent to or higher than Type 429, it is necessary to be Μη: 0.3 mass% or less, A1: 1. 2 mass% or less, and Ti: mass. 01 mass% or less. The present invention is further carried out in the above findings. The composition of the iron-based stainless steel of the present invention will be described. C: 0. 015 mass% or less c is an element which effectively increases the strength of steel, and when C containing more than 〇〇i5m(10), The reduction in toughness and formability becomes remarkable. Therefore, in the present invention, C is set. 0.015 mass%. In addition, from the viewpoint of ensuring formability, C is preferably as low as possible, preferably 0.008% by mass or less. On the other hand, in order to secure the strength of the member as an exhaust system, c is preferably Please pick it up. It is better for 〇· 〇〇2~0· 〇〇8 fflass%.

Si : 5 mass%以下以係作為脫氧材料而添加者。較佳為添加〇 · 〇5田㈣以上。又，Si具有本發明所著眼之提高耐氧化性之效果，作無法獲得八1那樣之效果。另一方面，根據圖6可知，超過 098107277 200946694 0· 5 mass%之Si之過剩添加，無法獲得與SUS444同等以上為 0.5 mass%。會導致耐鏽制離性降低，從而之耐氧化性。因此，SiU& Μη : 0. 5 mass%以下 Μη係提高鋼之強度之元素，又，亦且用。較佳為添加0.05_s以上。然而，過剩:^劑之作溫下容易生成r相’從而使耐熱性降低。〇知，若添加超過山㈣之Μη，則無法獲得與據= 同等以上之恤，從而無料成本發明之目的仰9 明中Μη設為0.5 massUx下。本發 P : 〇· 04 mass%以下較理想的是僅可能地降低其〇· 04 mass%以下。較佳為， P係會降低韌性之有害元素，含量。因此，本發明中，ρ設為設為0. 03 mass%以下。 S : 0· 006 mass%以下 S係會降低延伸率及r值、對成形性造成不良影響之同時會降低作為不鏽鋼之基本特性之耐触的有害元素，因此，較理想的是儘可能地降低其含量。因此，本發明中，s設為〇. 006 mass%以下。較佳為，設為〇· 〇〇3随％以下。Si : 5 mass% or less The system is added as a deoxidizing material. It is preferable to add 〇 · 〇 5 fields (four) or more. Further, Si has an effect of improving the oxidation resistance of the present invention, and the effect of the eighth one cannot be obtained. On the other hand, as shown in Fig. 6, it is found that excessive addition of Si exceeding 098107277 200946694 0·5 mass% cannot be obtained as 0.5 mass% or more with SUS444 or more. This results in a decrease in rust resistance and thus oxidation resistance. Therefore, SiU & Μ η : 0.5 mass % or less Μ η is an element which increases the strength of steel, and is also used in combination. It is preferred to add 0.05_s or more. However, the excess: the agent is easy to generate the r phase at a temperature to lower the heat resistance. 〇 know that if you add more than 山η of the mountain (4), you will not be able to obtain a shirt equal to or equal to the data, so that the purpose of the invention is set to 0.5 massUx. The present invention P: 〇· 04 mass% or less It is desirable to reduce only 〇·04 mass% or less. Preferably, the P system reduces the harmful elements and content of the toughness. Therefore, in the present invention, ρ is set to 0.03 mass% or less. S : 0· 006 mass% or less S system will lower the elongation and r value, adversely affect the formability, and reduce the harmful elements that are the basic characteristics of stainless steel. Therefore, it is desirable to reduce as much as possible. Its content. Therefore, in the present invention, s is set to 〇.006 mass% or less. Preferably, it is set to 〇· 〇〇3 with % or less.

Cr : 16〜20 mass% 〇係有效地提高作為不鏽鋼之特徵之耐敍性、耐氧化性之重要元素，若未滿16 mass%，則無法獲得充分之耐氧化 098107277 11 200946694 性。另一方面，Cr係於室溫下使鋼固溶強化而硬質化、低延展性化之元素，尤其當含有超過20 mass%之Cr時，上述弊害會變得顯著，從而無法獲得與Type429同等以上之加工性及韌性。因此，本發明中，Cr設為16〜20 mass%之範圍。較佳為’設為16〜19 mass%之範圍。 N : 0· 015 mass%以下 N係會降低鋼之韌性及成形性之元素，當含有超過〇.〇15 mass%之N時，上述降低會變得顯著。因此，n設為〇.〇15 mass%以下。再者，當要求更高之韌性之情形時，應進一步降低N之含量，較佳為未滿〇. 〇1〇 mass%。Cr : 16 to 20 mass% lanthanum is an important element for improving the resistance and oxidation resistance of stainless steel. If it is less than 16 mass%, sufficient oxidation resistance cannot be obtained. 098107277 11 200946694 Properties. On the other hand, Cr is an element which hardens and hardens steel by solid solution at room temperature, and particularly when it contains more than 20 mass% of Cr, the above-mentioned disadvantages become remarkable, and it is impossible to obtain the same as Type429. The above processability and toughness. Therefore, in the present invention, Cr is set in the range of 16 to 20 mass%. Preferably, it is set to a range of 16 to 19 mass%. N: 0· 015 mass% or less The N-based element which lowers the toughness and formability of steel, and when it contains N mass% more than 〇.〇15, the above-mentioned reduction becomes remarkable. Therefore, n is set to 〇.〇15 mass% or less. Furthermore, when higher toughness is required, the content of N should be further reduced, preferably less than 〇1〇 mass%.

Nb : 0.3〜0·55 mass%Nb : 0.3~0·55 mass%

Nb係具有形成並固定C、N與碳氮化物、提高耐餘性及成形性、焊接部之耐晶界腐姓性之作用，同時具有使古田強产上升而提高熱疲勞特性之效果的元素。上述效里又双果於添加〇. 3 mass%以上之Nb時得到確認。另一方面，超题 υ·55 mass% 之添加’容易析出Laves相，從而脆性會降低。因設為0.3〜0.55 mass%之範圍。較佳為，設為〇 υ. 4〜0.5 mass% 之範圍。 SS/oNb has an effect of forming and fixing C, N and carbonitrides, improving the durability and formability, and resisting the grain boundary corrosion resistance of the welded portion, and having an effect of increasing Gutian's strong production and improving the thermal fatigue characteristics. . In the above-mentioned effect, the double fruit was confirmed when N. 3 mass% or more of Nb was added. On the other hand, the addition of 超·55 mass% is easy to precipitate the Laves phase, and the brittleness is lowered. It is set to a range of 0.3 to 0.55 mass%. Preferably, it is set to a range of 〇 υ 4 to 0.5 mass%. SS/o

Ti : 〇. 01 mass%以下Ti : 〇. 01 mass% or less

Ti係與Nb相比容易與n鍵結而容易形成報大之素’該粗大之TiN發揮著切槽之作用，可使韌性明jlN之兀尤其，如圖9所示，當Ti之含量超過〇. 〇丨讯⑽戏低。 098107277 12 200946694 良影響將變得顯著。因此，本發明中，τ· r丨1限制為0.01mass% 以下。Ti is more likely to form N-bonds than Nb, and the TiN plays a role of grooving. This makes it possible to make a toughness, especially as shown in Figure 9, when the content of Ti exceeds 〇. 〇丨 ( (10) The play is low. 098107277 12 200946694 Good influence will become significant. Therefore, in the present invention, τ·r丨1 is limited to 0.01 mass% or less.

Mo : 0. 1 mass%以下 MQ係高價之元素，根據本發明之主旨考慮亦不能積極添加。然而，㈣會自作為原料之廢料等而混入〇· ι随％以下。因此，Mo設為〇· 1 mass%以下。 W ·· 0. 1 mass%以下 ❹ W係與Mo同樣高價之元素，根據本發明之主旨考慮亦不能積極添加。然而，有時會自作為原料之廢料等混入q i mass%以下。因此，w設為〇.丨mass%以下。Mo: 0.1 mass% or less The MQ high-priced element is not actively added in accordance with the gist of the present invention. However, (4) it will be mixed with 〇· ι as a waste from raw materials. Therefore, Mo is set to 〇·1 mass% or less. W ·· 0. 1 mass% or less ❹ W is an element of the same high price as Mo, and it cannot be actively added according to the gist of the present invention. However, it may be mixed with q i mass% or less from waste materials or the like as raw materials. Therefore, w is set to 〇.丨mass% or less.

Gu : 1· 〇〜£. 5 mass% . Cu係對於提高熱疲勞特性而言非常有效之元素。如圖3 ' 所不，為了獲得與SUS444同等以上之耐熱疲勞特性，必須添加1· 0 mass%以上之Cu。然而，超過2. 5 mass%之添加， ❿會於熱處理後之冷卻時析出ε-Cu，從而使鋼硬質化，同時於熱加工時容易引起脆化。更為重要的是，Cu之添加雖提尚了耐熱疲勞特性，但鋼自身之耐氧化性卻降低，總體而言’对熱性會降低。雖然其原因尚不十分清楚，但一般認為 -係因為所生成之鑷正下方之脫以層中Μ會增厚，從而抑制了作為提高不鏽鋼本來之耐氧化性之元素、即^之再擴散。因此’ Cu設為1.〇〜2 5職痛之範圍。更佳為，設為 11〜1.8 mass%之範圍。 098107277 13 200946694 A1 : 0.2〜1.2 mass% 糸不般用於提高添加有Cu之鋼之耐一化性的必不可缺之元素。尤其為了獲得作為本發明之目的乳與麗44同等以上之耐氧化性L加0.2 fflassu：^ 之Μ。另-方面，如圖8所示，超過12祕％而添加鋼會硬質化從而無法獲得與Type429同等以上之輪性，因此，將上限設為1. 2 mass%。較佳為，設為〇. 3〜κ 〇贴⑽ 之範圍。 ° 對於本發明之肥粒鐵系不鏽鋼而言，除了上述必需之成八以外’可進而於下述之範圍内添加自B、醒、Zr、V、= 及Ni中所選擇之1種或2種以上。 B : 0· 003 mass%以下 B係對於提高加王性、尤其2次加卫性有效之元素。該顯著之效果能夠藉由添加0_0005 mass%以上之B而獲得，但超過0_ 003 massW #之添加，會生成βΝ❿使得加工性降低。因此，於添加Β之情形時，設為〇〇〇3mass%以下。更佳為，設為0.0005〜0.002 mass%之範圍。 _ : 08 mass%以下、Zr : 〇. 5贴域以下 _(稀土類元素）及Zr中之任—者係改善财氧化性之元素本發明中’可視需要而進行添加。為了獲得上述效果，較佳為分別添加〇 01 mass%以上之_，〇〇5 以上之 k。然而’ REM之超過〇· 08 raass%之添加會使鋼脆化，又， 098107277 14 200946694Gu : 1· 〇~£. 5 mass% . Cu is a very effective element for improving thermal fatigue properties. As shown in Fig. 3', in order to obtain the thermal fatigue resistance equivalent to or higher than SUS444, it is necessary to add 1·0 mass% or more of Cu. However, when added in an amount of more than 2.5 mass%, ruthenium precipitates ε-Cu upon cooling after heat treatment, thereby hardening the steel and causing embrittlement at the time of hot working. More importantly, although the addition of Cu promotes the thermal fatigue resistance, the oxidation resistance of the steel itself is lowered, and overall, the heat resistance is lowered. Although the reason is not fully understood, it is generally considered that the enthalpy in the layer which is directly under the enthalpy formed is thickened, thereby suppressing the re-dispersion which is an element which improves the original oxidation resistance of stainless steel. Therefore, 'Cu is set to 1. 〇~2 5 range of occupational pain. More preferably, it is set to a range of 11 to 1.8 mass%. 098107277 13 200946694 A1 : 0.2~1.2 mass% 糸 It is not essential for improving the resistance of steel with added Cu. In particular, in order to obtain the same oxidation resistance L and 0.2 fflassu:^ as the purpose of the present invention. On the other hand, as shown in Fig. 8, the upper limit is set to 1.2 mass%, and the steel is hardened to be more than 12%. Preferably, it is set to the range of 〇. 3~κ 〇贴(10). ° For the ferrite-based iron-based stainless steel of the present invention, one or two selected from B, awake, Zr, V, =, and Ni may be added in addition to the above-mentioned necessity. More than one species. B : 0· 003 mass% or less B is an effective element for improving the kingness, especially for the second time. This remarkable effect can be obtained by adding 0_0005 mass% or more of B, but when more than 0_003 massW # is added, βΝ❿ is generated to lower the workability. Therefore, when adding Β, it is set to 〇〇〇 3mass% or less. More preferably, it is set to a range of 0.0005 to 0.002 mass%. _ : 08 mass% or less, Zr : 〇. 5 affixing area _ (rare earth element) and any of Zr are elements for improving the oxidizing property. In the present invention, it is added as needed. In order to obtain the above effects, it is preferable to add k of 〇 01 mass% or more and k of 〇以上 5 or more. However, the addition of 'REM' more than 〇·08 raass% makes the steel embrittlement, 098107277 14 200946694

Zr之超過0.5 mass%之添加’會析出&金屬間，而使鋼脆化。因此，於添加_之情形時，設為〇.〇8從以下，於添加斤之情形時，設為G.5 mass%以下。一 V : 〇. 5 mass%以下 ^係錢地提高加工性及耐氧化性之元素，尤其為耐乳化性提高之效果，較佳為添加〇15祕％以上之^件而，超過〇. 5 mass%之過剩添加，會析出粗大之K然 ❹ 從而使表面性狀劣化。因此，於添加V之情形時，較佳A、’ 加〇. 5 mass%以下，較佳為於〇為添添加。 U.4嶋之fe圍進行 C〇 : 〇· 5 mass%以下係有效地提高祕之元素，較佳為添加The addition of more than 0.5 mass% of Zr 'precipitates & intermetallic, making the steel embrittled. Therefore, in the case of adding _, it is assumed that 〇.〇8 is from the following, and when it is added, it is set to G.5 mass% or less. a V: mass. 5 mass% or less ^ The element which improves the workability and oxidation resistance, especially the effect of improving the emulsification resistance, is preferably added to the 〇15%% or more, more than 〇. 5 When the mass% is excessively added, coarse K is precipitated and the surface properties are deteriorated. Therefore, in the case of adding V, it is preferred that A, 'grinding. 5 mass% or less, preferably 〇 is added. U.4嶋fe circumference is carried out C〇 : 〇· 5 mass% or less is effective to improve the secret elements, preferably added

上。然而，Co係高價之元素，又，〇M 加，上述效果p便超過〇· 5 mass%而添上述效果亦達到飽和。因此，於添加 ❿ 佳設為0.5 raass%以下。更佳為厂’乂範圍。 π · ϋ. 2 maSs%之on. However, Co is a high-priced element, and 〇M is added, and the above effect p is more than 〇·5 mass%, and the above effect is also saturated. Therefore, it is set to 0.5 raass% or less after adding ❿. Better for the factory's range. π · ϋ. 2 maSs%

Ni . 0. 5 mass%以下 mrr之元素。為了獲得上錢果，㈣為㈣ Γ，：。二而，Nl係高價，又，· L此，於㈣下會生成"目，從而使耐氧化性降低。、’於添加Ni之情形時，較佳為，設為0. 5 mass%以下。更佳為，設為〇· 05〜0· 4 mass%之範圍。 098107277 15 200946694 繼而，對本發明之肥粒鐵系不鏽鋼之製造方法進行說明。本發明之不鏽鋼之製造方法只要係肥粒鐵系不鏽鋼之通常之製造方法則可較佳地使用，並未作特別限定。例如，較佳為，於轉爐、電爐等公知之炫解爐中溶製出鋼，或者進一步經過澆鑄精煉、真空精煉等2次精煉而形成具有上述之本發明之成分組成之鋼，繼而，利用連續鑄造法或者造塊—分塊壓延法使其熔鋼形成為鋼片（鋼坯），進行熱軋而形成熱軋板，且視需要對熱軋板實施退火，並進一步對該熱軋板進行酸洗、冷軋、精退火，經過酸洗等工程後而形成冷軋退火板。對於上述冷軋而言，可進行一次，或***中間退火而進行兩次以上之冷軋，又’冷軋、精退火、酸洗之各工程可循環進行。進而，亦可視情況而省略熱軋板退火，於要求鋼板表面之光澤性之情形時，亦可於冷軋後或者精退火後，實施表皮輥軋。再者，較佳為，上述熱軋前之鋼坯加熱溫度為1000 〜1250°c之範圍’熱軋板退火溫度為9〇〇〜ii〇〇°c之範圍’ 精退火溫度為900〜112(TC之範圍。以如上所述之方式而獲得之本發明之肥粒鐵系不鏽鋼，其後’根據各自之用途而實施切斷加工、彎曲加工、麼製加工等加工，從而形成為汽車或機器腳踏車之排氣管、轉換器外殼或火力發電廠之排氣管道等高溫環境下所使用的各種排氣系統構件。再者，上述構件中所使用之本發明之不鏽鋼，並不限定於冷軋退火板，亦可用作熱軋板或熱軋板退火，進 098107277 16 200946694 而亦可視需要而用作除鏽處理。又，組裝於上述構件時之烊接方法並未作特別限定，可使用MIG(Metal Inert Gas，金屬惰性氣體）、MAG(Metal Active Gas，金屬活性氣體）、 TIG(Tungsten Inert Gas，鎢極惰性氣體）等通常之弧焊、或點焊、縫焊等電阻焊接，及電縫焊接中所使用之高頻電阻焊接’高頻感應焊接，雷射焊接等方法。 [實施例1] ❹ 於真空熔解爐中熔製出具有表1所示之成分組成之No l 〜No· 27之鋼’並進行鑄造而形成5〇 kg鋼塊，經過鍛造後分割為兩部分。然後，將分割為兩部分之其中一鋼塊加熱至 1170°C後，進行熱軋而形成板厚為 5 mm之熱軋板，以l〇2〇t： •之溫度對熱軋板進行退火、酸洗、壓下率為6〇%之冷軋，且以1030°C之溫度進行精退火，然後以平均冷卻速度為 20 C/s進行冷卻、酸洗，從而形成板厚為2 _之冷軋退火 ❹ 板’並提供給以下之耐氧化性試驗及衝擊試驗。再者，作為參考’關於表1之N〇. 28〜No. 32所示之SUS444、Type429 及W02003/004714號手冊、日本專利特開2006-117985號公報、日本專利特開2000-297355號公報之發明鋼，亦以與上 - 述相同之方式製作冷軋退火板，並提供給相同之評估試驗。 - 〈大氣中連續氧化試驗（continuance oxidation test in air) > 自如上述方式而獲得之各種冷軋退火板切出30 mmx20 mm 098107277 17 200946694 之樣品，並於樣品上部開有4mm0之孔，利用# 32〇之砂紙對表面及端面進行研磨、脫脂後，懸掛於加熱保持為之大氣環境之爐内，且保持300小時。於試驗後對樣品之質量進行測定，並求出與預先所測定之試驗前之質量之差，從而算出氧化増#(g/m2)。再者’試驗各實麵:欠，利用其平均值對耐連續氧化性進行評估。、 <大氣中循環氧化試驗（CyCHc 〇xidati〇n test in air)> 自上述各種之冷軋退火板切出3〇腿χ2〇 mm之樣品，並於樣品上部開有4 mm φ之孔’利用# 32〇之砂紙對表面及端面Ni . 0. 5 mass% or less The element of mrr. In order to obtain the money, (4) is (4) Γ,:. Second, Nl is expensive, and L, this will generate " under (4), so that oxidation resistance is reduced. 5 mass%以下。 In the case of the addition of Ni, preferably set to 0. 5 mass% or less. More preferably, it is set to 〇· 05~0·4 mass%. 098107277 15 200946694 Next, a method of producing the ferrite-based stainless steel of the present invention will be described. The method for producing a stainless steel according to the present invention can be preferably used as long as it is a usual method for producing a ferrite-based stainless steel, and is not particularly limited. For example, it is preferable to melt the steel in a known buckling furnace such as a converter or an electric furnace, or to further refine the steel having the composition of the present invention by secondary refining such as casting refining or vacuum refining, and then use it. The continuous casting method or the agglomerating-blocking calendering method forms the molten steel into a steel sheet (slab), performs hot rolling to form a hot rolled sheet, and anneals the hot rolled sheet as needed, and further performs the hot rolled sheet. Pickling, cold rolling, fine annealing, after pickling and other engineering to form a cold rolled annealed sheet. For the above cold rolling, it may be carried out once or by inserting an intermediate annealing to perform cold rolling for two or more times, and each of the processes of 'cold rolling, finish annealing, and pickling may be cycled. Further, the hot-rolled sheet annealing may be omitted as the case may be. When the glossiness of the surface of the steel sheet is required, the skin rolling may be performed after cold rolling or after finish annealing. Further, preferably, the slab heating temperature before the hot rolling is in the range of 1000 to 1250 ° C. The hot rolling sheet annealing temperature is in the range of 9 〇〇 to ii 〇〇 ° C. The finishing annealing temperature is 900 to 112 ( Scope of TC. The ferrite-based iron-based stainless steel of the present invention obtained as described above is formed into a car or a machine by performing cutting, bending, or manufacturing processing according to the respective applications. Various exhaust system components used in a high temperature environment such as an exhaust pipe of a bicycle, a converter casing, or an exhaust pipe of a thermal power plant. Further, the stainless steel of the present invention used in the above member is not limited to cold rolling. The annealed sheet can also be used as a hot-rolled sheet or a hot-rolled sheet for annealing, and can be used as a rust-removing treatment as needed. Further, the splicing method for assembling the above-mentioned members is not particularly limited and can be used. Ordinary arc welding such as MIG (Metal Inert Gas), MAG (Metal Active Gas), TIG (Tungsten Inert Gas), etc., or resistance welding such as spot welding or seam welding. High-frequency electric resistance welding used in electric seam welding 'high-frequency induction welding, laser welding, etc. [Example 1] 熔 No l to No in the vacuum melting furnace having the composition shown in Table 1 · 27 steel 'and cast to form 5 〇 kg steel block, after forging, divided into two parts. Then, one of the steel blocks divided into two parts is heated to 1170 ° C, then hot rolled to form a plate thickness For the hot-rolled sheet of 5 mm, the hot-rolled sheet is annealed, pickled, and rolled at a reduction ratio of 6〇% at a temperature of 10〇2〇t: • and is subjected to finish annealing at a temperature of 1030 ° C. Then, it was cooled and pickled at an average cooling rate of 20 C/s to form a cold-rolled annealed slab having a thickness of 2 Å and supplied to the following oxidation resistance test and impact test. Further, as a reference The invention steels of the SUS444, Type 429, and WO2003/004714, and the inventions of the Japanese Patent Laid-Open Publication No. 2000-297985, and the Japanese Patent Publication No. 2000-297355 The cold rolled annealed sheets were fabricated in the same manner as above and provided to the same evaluation test. - "continuance oxidation test in air" > Samples of 30 mm x 20 mm 098107277 17 200946694 were cut out from various cold rolled annealed sheets obtained as described above, and 4 mm0 holes were opened in the upper part of the sample. The 32 〇 sandpaper was ground and degreased, and then suspended in a furnace maintained in an atmosphere of heat and maintained for 300 hours. After the test, the mass of the sample was measured, and the difference from the mass before the test measured in advance was determined to calculate yttrium oxide # (g/m2). Furthermore, the actual faces of the test were: owed, and the average oxidation resistance was evaluated using the average value. <Cyclic Circulating Oxidation Test (CyCHc 〇xidati〇n test in air)> A sample of 3〇2χ2〇mm was cut out from the above various cold-rolled annealed sheets, and a hole of 4 mm φ was opened in the upper part of the sample. 'Using #32〇 sandpaper on the surface and end face

進行研磨、脫脂後，於大氣環境中，進行於l〇(TC與95(TC 之間循環升溫、降溫之氧化試驗。再者，升溫、降溫速度分別設為5°匚/36(：、1.5^：/360，保持時間於1〇〇。(：設為1111][11，於950°c設為25 min’並將其進行600循環。耐循環氧化性之评估中，對試驗後之樣品之質量進行測定，並求出與預先測定之試驗前之質量之差，從而求出鏽剝離量（g/m2)。再者，試驗各實施兩次，利用其平均值對耐循環氧化性進行評估。 <夏比衝擊試驗> 自上述各種之冷軋退火板’各採取3條於壓延方向直角地形成v凹槽之夏比衝擊試驗片，以_4(rc之溫度進行夏比衝擊試驗，測定出脆性破面率，並求出3條試驗片之平均值，從而對韌性進行評估。 098107277 18 200946694 [實施例2] 將實施例1中分割為兩部分之5叫鋼塊之剩餘鋼塊加熱至U70C後’進行熱軋，從而形成厚：3〇咖父寬：15〇匪之薄鋼片。然後，對該薄鋼片進行鍛造，形成35 _□(見方）之鋼條，以1030 C之溫度進行退火後，進行機械加工，從而加工為如圖1所示之尺寸之熱疲勞試驗片，並提供給下述之熱疲勞試驗。再者，作為參考例，與實施例丨同樣，關 ❹於SUS444、Type429及W02003/004714號手冊、日本專利特開2006-117985號公報、日本專利特開2000-297355號公報之發明鋼亦同樣製作試料，並提供給熱疲勞試驗。〈熱疲勞試驗（thermal fatigue test)〉熱疲勞試驗中，以限制率為〇· 35，在丨⑽艽與85(rc之溫 - 度間循環而進行升溫、降溫’從而測定出熱疲勞壽命。此時，升溫速度（heating rate)及降溫速度（co〇nng rate)分別設 ❹ 為l〇°C/sec，100°C之保持時間為2min，850X：之保持時間 (holding time)為5 min。又，對於熱疲勞壽命（thermal fatigue life)而言，係將i00°c時所檢測出之負重除以試驗片均熱平行部之剖面積而算出應力，從而設為應力相對於 ' 前一循環之應力而開始連續地降低時之最小循環數。 * 將上述實施例1之大氣中連續氧化試驗、大氣中循環氧化試驗、夏比衝擊試驗之結果及實施例2之耐熱疲勞性試驗之結果一併示於表2中。根據表2可知，適合於本發明之發明 098107277 19 200946694 例之鋼均具有與SUS444同等以上之财氧化特性和财熱疲勞特性，同時具有與Type429同等以上之韌性，從而滿足本發明之目標。而與此相對，超過本發明之範圍值比較例之鋼或者先行技術之參考例之鋼，财氧化特性、对熱疲勞特性及母材之韌性均不優異，從而無法獲得作為本發明目標之特性。 (產業上之可利用性）本發明之鋼不僅適於汽車等之排氣系統構件用，亦可適用於要求同樣之特性之火力發電系統之排氣系統構件或固體氧化物型之燃料電池用構件。 098107277 20After grinding and degreasing, it is subjected to an oxidation test in which the temperature is raised and the temperature is lowered between TC and 95 (TC). In addition, the temperature rise and the temperature drop rate are set to 5°匚/36 (:, 1.5, respectively). ^:/360, hold time at 1〇〇. (: set to 1111] [11, set to 25 min at 950 °c and carry out 600 cycles. In the evaluation of resistance to cyclic oxidation, the sample after the test The mass was measured, and the difference from the mass before the test measured in advance was determined to determine the amount of rust peeling (g/m 2 ). Further, the test was carried out twice, and the cycle resistance was measured by the average value thereof. Evaluation: Charpy impact test> Three kinds of Charpy impact test pieces each forming a v-groove at right angles in the rolling direction were taken from each of the above-mentioned various cold-rolled annealed sheets, and Charpy impact was performed at a temperature of _4 (rc) In the test, the brittle fracture rate was measured, and the average of the three test pieces was determined to evaluate the toughness. 098107277 18 200946694 [Embodiment 2] The remainder of the steel block divided into two parts in Example 1 is called a steel block. After the steel block is heated to U70C, it is hot rolled to form a thick: 3 〇Grandfather width: 15 The thin steel sheet is then forged, and the thin steel sheet is forged to form a steel strip of 35 _□ (see square), which is annealed at a temperature of 1030 C, and then machined to be processed into a size as shown in FIG. The thermal fatigue test piece is provided to the following thermal fatigue test. Further, as a reference example, as in the case of the embodiment, the SUS444, Type 429, and W02003/004714 manuals, and Japanese Patent Laid-Open No. 2006-117985 The invention steel of the Japanese Patent Publication No. 2000-297355 is also prepared in the same manner and supplied to the thermal fatigue test. <thermal fatigue test> In the thermal fatigue test, the limiting ratio is 〇·35, in丨(10)艽 and 85 (the temperature and temperature of rc are cycled to increase and decrease the temperature) to determine the thermal fatigue life. At this time, the heating rate and the cooling rate (co〇nng rate) are set to 〇. °C/sec, 100°C hold time is 2min, 850X: hold time is 5 min. Also, for thermal fatigue life, it is detected at i00°c The load is divided by the test piece soaking The stress is calculated by the cross-sectional area of the parallel portion, and the minimum number of cycles when the stress starts to decrease continuously with respect to the stress of the previous cycle is set. * The atmospheric oxidation test and the atmospheric oxidation test in the above Example 1 are carried out. The results of the Charpy impact test and the results of the heat fatigue resistance test of Example 2 are shown in Table 2. According to Table 2, the steels of the inventions of the invention 098107277 19 200946694 are all equivalent to SUS444. The oxidizing property and the fragile fatigue property have the same or higher toughness as the Type 429, thereby satisfying the object of the present invention. On the other hand, the steel of the comparative example of the steel of the comparative example of the present invention or the reference example of the prior art is not excellent in the oxidation property, the thermal fatigue property, and the toughness of the base material, so that the characteristics which are the object of the present invention cannot be obtained. . (Industrial Applicability) The steel of the present invention is suitable not only for an exhaust system component of an automobile or the like, but also for an exhaust system component or a solid oxide fuel cell of a thermal power generation system requiring the same characteristics. member. 098107277 20

〔I丨5 孽發明例發明例發明例發明例發明例發明例發明例發明例發明例發明例發明例發明例 1 比較例I 比較例比較例比較例比較例比較例化學成分(mass%) 械 l l l l l B/0. 0009 V/0.051 Co/0.13 B/0.0011 Zr/0. 08 1—H cr> CM r-H o o s S § s ^ i l 1 l 0.008 0.007 | o.oii I 0.005 I 0.006 1 0.007 I I 0.007 I 0.008 0.004 I 0.006 I 0.003 0.004 1 0.009 | 1 0.008J | 0.009 I | 0.004 I 1 0.005 I 0.007 G> <=> CD i—H <3> C? 〇· <=> g 〇 CZ5 o C5 o ¢=5 s o g c=> g <=> s C5 o <=> <=> 〇· C3> s c=> 0.04 £ <=> s C=5 S c=> s C5 1—H c=> c? s CD i—H <=> o s (〇 C3 C=) CNI o o’ C> O’ s <=> CZ3 <=? s c=> o • 1—( 0.006 0.002 0.006 | o.ooi | 0.003 I | 0.004 I 1 0.007 I 0.004 0.001 I 0.003 I 0.002 0.003 10.006 I | 0.004 I [0.004 I 1 0.009 I 1 0.095 I 0.002 CO 寸 d 0.41 OO 寸 ci 0.49 I 0:41 CO ¢=5 0.46 0.45 寸寸 cz> I 0.43 I CD C=> 0.41 ci c^> 寸 <=> T"H CZ5 1 0.42 I CD θ LO CO CO LO CO 呀 03 Oi <NJ CO L〇 L〇 CO T—H C<i 寸 03 CO CO OO CO CO 寸 s oo c<l oo LO LO 寸 r—'H 1—< H 1 < 1—H τ·Ή 1—H CZ5 ώ 17.5 LiLl L—17.7 1 16.3 I OO 卜^ Lim 17.2 ... —. 17.9 17· 7 18.9 17.4 T—H f— iiLn —17.4」卜^ CO 卜· 00 0.004 | | 0.002 I | o.ooi | 0.001 I 0.002 1 1 0.004 I 1 0.002 I 0.003 0.002 1 0.002 I 0.005 0.002 | 0.002 I | 0.004 I | 0.003 ] 1 0.002 1 | 0.003 I 0.002 Ou 0.032 0. 026 | | 0.022 I 0.032 | 0.022 I i 0. 029 I | 0.022 I 0.029 0.026 1 0.031 I 0.027 0.021 | 0.030 I | 0.028 I | 0.028 ] 1 0.020 1 | 0.029 I 0.031 > 4 <=> c=> | 0.48 I C5 OO S <=5 [ML LO CO C5 LO LO d CO C3 0.41 d L62 M9 1 0.72 1 LiaiJ (>3 T"H Μ | 0.13 I oo <NI CD | 0.33 I r__H C=5 | 0.42 | | 0.28 I c=> 0.23 OO | 0.26 | 05 CO a g LQ CO o CO CO c=> LO LO 〇 LA41J LO 1—H o CO c=> 05 r-H <=> | 0.35 I OO oa c=> c=> OO CO c> (Nl C<S <=> <=> 0.39 &3 c=> CT5 Cvl ci 卜 i—H c? CO c? | 0.23 | 0.32 oo <=> | 0.34 cS Ο 0.006 0.005 | 0.005 0.008 | | 0.005 1 | 0.003 I | 0.006 | 0.007 0.008 | 0.004 I 0.006 0.008 | 0.006 I | 0.008 | 0.006 | | o.oii | 0.007 0.005 嚴 ^H (NI CO 1 ίο CO 卜 OO 03 〇> OO CO 15 CO 1—^ t— 1 H OO t-H[I 丨孽孽发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明 mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas mas Lllll B/0. 0009 V/0.051 Co/0.13 B/0.0011 Zr/0. 08 1—H cr> CM rH oos S § s ^ il 1 l 0.008 0.007 | o.oii I 0.005 I 0.006 1 0.007 II 0.007 I 0.008 0.004 I 0.006 I 0.003 0.004 1 0.009 | 1 0.008J | 0.009 I | 0.004 I 1 0.005 I 0.007 G><=> CD i-H <3> C? 〇· <=> g 〇CZ5 o C5 o ¢=5 sogc=> g <=> s C5 o <=><=> 〇· C3>sc=> 0.04 £ <=> s C=5 S c => s C5 1—H c=> c? s CD i—H <=> os (〇C3 C=) CNI o o' C> O' s <=> CZ3 <=? o= 1—( 0.006 0.002 0.006 | o.ooi | 0.003 I | 0.004 I 1 0.007 I 0.004 0.001 I 0.003 I 0.002 0.003 10.006 I | 0.004 I [0.004 I 1 0.009 I 1 0.095 I 0.002 CO inch d 0.41 OO inch ci 0.49 I 0:41 CO ¢=5 0.46 0.45 inch cz> I 0.43 I CD C=> 0.41 ci c^>inch<=>T"H CZ5 1 0.42 I CD θ LO CO CO LO CO 呀03 Oi <NJ CO L〇L〇CO T-H C< i inch 03 CO CO OO CO CO inch s oo c<l oo LO LO inch r—'H 1—< H 1 < 1—H τ·Ή 1—H CZ5 ώ 17.5 LiLl L—17.7 1 16.3 I OO卜^ Lim 17.2 ... —. 17.9 17· 7 18.9 17.4 T—H f— iiLn —17.4” Bu ^ CO Bu· 00 0.004 | | 0.002 I | o.ooi | 0.001 I 0.002 1 1 0.004 I 1 0.002 I 0.003 0.002 1 0.002 I 0.005 0.002 | 0.002 I | 0.004 I | 0.003 ] 1 0.002 1 | 0.003 I 0.002 Ou 0.032 0. 026 | | 0.022 I 0.032 | 0.022 I i 0. 029 I | 0.022 I 0.029 0.026 1 0.031 I 0.027 0.021 | 0.030 I | 0.028 I | 0.028 ] 1 0.020 1 | 0.029 I 0.031 > 4 <=>c=> | 0.48 I C5 OO S <=5 [ML LO CO C5 LO LO d CO C3 0.41 d L62 M9 1 0.72 1 LiaiJ (>3 T"H Μ | 0.13 I oo <NI CD | 0.33 I r__H C=5 | 0.42 | | 0.28 I c=> 0.23 OO | 0.26 | 05 CO ag LQ CO o CO CO c=> LO LO 〇LA41J LO 1—H o CO c=> 05 rH <=> | 0.35 I OO oa c=&gt ; c=> OO CO c> (Nl C<S <=><=> 0.39 & 3 c=> CT5 Cvl ci i-H c? CO c? | 0.23 | 0.32 oo &lt ;=> | 0.34 cS Ο 0.006 0.005 | 0.005 0.008 | | 0.005 1 | 0.003 I | 0.006 | 0.007 0.008 | 0.004 I 0.006 0.008 | 0.006 I | 0.008 | 0.006 | | o.oii | 0.007 0.005 严^H (NI CO 1 ίο CO OB 03 〇> OO CO 15 CO 1—^ t— 1 H OO tH

IfNzizz-OISg 200946694 〔2—5IfNzizz-OISg 200946694 [2-5

準比較例I 比較例比較例比較例發明例發明例發明例發明例發明例 SUS444 Type429 參考例1 參考例2 |參考例3 1 化學成分(mass%) 其他I 丨丨 i 丨 1 V:0.18 I V:0„ 22 V:0..38 V :0.20 V :0.. 23 丨 Ni/0.10 V/0., 10 2 g g ^ s ^ Ni/0.15 0.006 I 0.007 1 1 0.005 I 1 0.008 1 | 0.008 I | 0.007 | | 0.005 | | 0.007 | 1 0.006 1 | 0.008 I | 0.008 | 0.010 0.007 0.006 <=? C=5 s C=J s CD c=> s C3 <〇 C3 s C=5 (N1 C=3 C=> g C5 s CD <〇 d Μ 〇> ι»Η o C=5 s CZ5 § C=> c=> s C=> g CZ5 I 0.05 I s C3 OO r-H s CD y-^ o <=5 <〇〇 [0.007 I | 0.003 I 1 0.002 I o | 0.003 I I 0.008 I | 0.005 1 1 0.004 1 | 0.006 I lo. 003 I | 0.007 I 0.002 g 0.09 〇〇 ο 05 CO c> (=5 0.44 寸寸 C3 <NJ c=> CO <=> 0.45」 LO 寸 CD (NJ LO CD LO <=> CO CO 0.35 0.42 3 〇〇 οα Η CO CO 1-H <z> LO oo i-H CO <NI i-H C<i C<i OO C<l T-H i I s C=5 s o CO 05 r-H 1.36 1.65 ώ 17·5 1 1 ( — I i od > 1 17-9 1 1 17.6 1 LO 卜· 1-H 卜卜· I i σί i-H 1 18.2 1 LjmJ LO 17.02 18. 90 | 18.8 | 00 I o.ooi I 0.003 I o.ooi I 0.002 | 0.002 I | 0.003 1 | 0.002 1 I 0.003 I 0.002 1 0.003 I 0.004 0.002 0.003 0.0052 Oh 1 0.027 1 0.031 I | 0.025 1 i 0.030 | | 0.027 I | 0.025 I | 0.024 I | 0.027 | | 0.024 | | 0.031 I | 0.029 I 0.028 0.029 0.005 i '4 0.38 1 CD Eo CD c=> ¢=5 CO 呀 CD CO 寸 o' CO LO CD In <=> | 0.019 I | 0.028 | >1 i <〇 c=? 0.002 0.052 C3 CD CV3 CV3 <〇 oo CM o LO C<J <〇 C<J o 0.34 LO 〇 c=> oa 寸 cz? CO CO s C=3 0.54 g C3 ι-Η 〇· 寸 CD CO CO ¢=) 05 CsJ <=> CO (NJ CD | 0.09 | 0.32 CD s CO c=> oo o’ CM CO C=) 0.46 oa oa <=> 〇 1 0.007 1 | 0.008 I | 0.006 1 0.005 | 0.007 I [0.003 I | 0.006 1 | 0.007 I | 0.005 I | 0.008 I | 0.007 I 0.008 0.009 0.006 鋼No 0¾ §3 cS CO τιComparative Example I Comparative Example Comparative Example Comparative Example Invention Example Invention Example Invention Example SUS444 Type429 Reference Example 1 Reference Example 2 | Reference Example 3 1 Chemical composition (mass%) Other I 丨丨i 丨1 V: 0.18 IV :0„ 22 V:0..38 V :0.20 V :0.. 23 丨Ni/0.10 V/0., 10 2 gg ^ s ^ Ni/0.15 0.006 I 0.007 1 1 0.005 I 1 0.008 1 | 0.008 I 0.007 | | 0.005 | | 0.007 | 1 0.006 1 | 0.008 I | 0.008 | 0.010 0.007 0.006 <=? C=5 s C=J s CD c=> s C3 <〇C3 s C=5 (N1 C=3 C=> g C5 s CD <〇d Μ 〇> ι»Η o C=5 s CZ5 § C=>c=> s C=> g CZ5 I 0.05 I s C3 OO rH s CD y-^ o <=5 <〇〇[0.007 I | 0.003 I 1 0.002 I o | 0.003 II 0.008 I | 0.005 1 1 0.004 1 | 0.006 I lo. 003 I | 0.007 I 0.002 g 0.09 〇〇ο 05 CO c> (=5 0.44 inch C3 <NJ c=> CO <=> 0.45" LO inch CD (NJ LO CD LO <=> CO CO 0.35 0.42 3 〇〇οα Η CO CO 1-H <z> LO oo iH CO <NI iH C<i C<i OO C<l TH i I s C=5 so CO 05 rH 1.36 1.65 ώ 17·5 1 1 ( — I i od > 1 17-9 1 1 17.6 1 LO 卜 · 1-H 卜 · I i σί iH 1 18.2 1 LjmJ LO 17.02 18. 90 | 18.8 | 00 I o.ooi I 0.003 I o.ooi I 0.002 | 0.002 I | 0.003 1 | 0.002 1 I 0.003 I 0.002 1 0.003 I 0.004 0.002 0.003 0.0052 Oh 1 0.027 1 0.031 I | 0.025 1 i 0.030 | | 0.027 I | 0.025 I | 0.024 I | 0.027 | | 0.024 | | 0.031 I | 0.029 I 0.028 0.029 0.005 i '4 0.38 1 CD Eo CD c=> ¢=5 CO 呀 CD CO inch o' CO LO CD In <=> | 0.019 I | 0.028 | >1 i <〇c= 0.002 0.052 C3 CD CV3 CV3 <〇oo CM o LO C<J <〇C<J o 0.34 LO 〇c=> oa inch cz? CO CO s C=3 0.54 g C3 ι-Η 〇·inch CD CO CO ¢=) 05 CsJ <=> CO (NJ CD | 0.09 | 0.32 CD s CO c=> oo o' CM CO C=) 0.46 oa oa <=> 〇1 0.007 1 | 0.00 | 0.006 1 0.005 | 0.007 I [0.003 I | 0.006 1 | 0.007 I | 0.005 I | 0.008 I | 0.007 I 0.008 0.009 0.006 Steel No 03⁄4 §3 cS CO τι

LnoN 綦驭 ΐ9ς^6〒0003^弈瓦岭-4Β 卜·ΟΝ 綦srB$LOoo6 卜 179002迗#苳岭-4Β ,ΓΟ,ΟΝ 瀑涅^-W^^OO/COOOSM οLnoN 綦驭 ΐ9ς^6〒0003^弈瓦岭-4Β Bu·ΟΝ 綦srB$LOoo6 卜 179002迗#苳岭-4Β ,ΓΟ,ΟΝ Waterfall Nie ^-W^^OO/COOOSM ο

cof#%妹 ί%妹 I專妹S z,z.tsA0I860 200946694[表2]Cof#%妹 ί%妹 I sister S z,z.tsA0I860 200946694[Table 2]

鋼No 财熱性熱疲勞壽命 (循環數）脆性破面率 at-40°C (%) 備考氧化增量 (g/m2) 鐘剝離量 (g/m3) 1 21 3 1230 <5 發明例 2 20 2 1330 <5 發明例 3 21 2 1300 <5 發明例 4 21 2 1500 <5 發明例 5 17 <0. 1 1230 <5 發明例 6 20 1 1320 <5 發明例 7 21 2 1510 <5 發明例 8 21 2 1260 <5 發明例 9 22 3 1280 <5 發明例 10 20 1 1250 <5 發明例 11 22 3 1290 <5 發明例 12 21 2 1250 <5 發明例 13 80 10 1290 <5 比較例 14 11 <0_ 1 1400 50 比較例 15 14 1 820 <5 比較例 16 18 5 1210 <5 比較例 17 15 <0. 1 1350 15 比較例 18 15 <0. 1 1300 15 比較例 19 21 10 1210 <5 比較例 20 21 2 1380 15 比較例 21 20 1 700 <5 比較例 22 21 2 1320 20 比較例 23 15 1 1200 <5 發明例 24 15 1 1230 <5 發明例 25 14 0. 9 1210 <5 發明例 26 15 1 1240 <5 發明例 27 15 1 1210 <5 發明例 28 27 4 1120 10 SUS444 29 51 25 500 <5 Type429 30 >100 >100 1480 <5 參考例1 31 >100 >100 1240 <10 參考例2 32 >100 >100 1400 <10 參考例3 (註）參考例1 : W02003/004714之發明鋼No. 3、參考例2 :日本專利特開2006-117985之發明鋼No. 7、參考例3 :日本專利特開2000-297355之發明鋼No. 5 098107277 23 200946694 . 【圖式簡單說明】圖1係熱疲勞試驗片之說明圖。圖2係熱疲勞β式驗中之溫度、限制條件 conditions)之說明圖。圖3係表不Cu含量對熱疲勞特性所造成之影響之圖表。圖4係表不A1含量對耐氧化性（氧化增量（weight gain by oxidation))所造成之影響之圖表。圖5係表不A1含量對耐氧化性（鏽剝離量（spoiling 〇 amounts of scale))所造成之影響之圖表。圖6係表示Si含量對耐氧化性（鏽剝離量）所造成之影響之圖表。圖7係表示Μη含量對韌性（脆性破面率（brittle fracture surface ratio))所造成之影響之圖表。 ‘ 圖8係表示A1含量對執性（脆性破面率）所造成之影響之圖表。 Ο 圖9係表示Ti含量對韌性（脆性破面率）所造成之影響之圖表。 098107277 24Steel No Thermal thermal fatigue life (cycle number) Brittle fracture rate at-40 ° C (%) Preparation oxidation increment (g / m2) Bell peel amount (g / m3) 1 21 3 1230 < 5 invention example 2 20 2 1330 <5 invention example 3 21 2 1300 <5 invention example 4 21 2 1500 <5 invention example 5 17 <1. 1212 <5 invention example 6 20 1 1320 <5 invention example 7 21 2 1510 <5 invention example 8 21 2 1260 <5 invention example 9 22 3 1280 <5 invention example 10 20 1 1250 <5 invention example 11 22 3 1290 <5 invention example 12 21 2 1250 <5 Inventive Example 13 80 10 1290 <5 Comparative Example 14 11 <0_ 1 1400 50 Comparative Example 15 14 1 820 <5 Comparative Example 16 18 5 1210 <5 Comparative Example 17 15 <1. 1350 15 Comparative Example 18 15 <0. 1 1300 15 Comparative Example 19 21 10 1210 <5 Comparative Example 20 21 2 1380 15 Comparative Example 21 20 1 700 <5 Comparative Example 22 21 2 1320 20 Comparative Example 23 15 1 1200 <5 Inventive Example 24 15 1 1230 < 5 Inventive Example 25 14 0. 9 1210 < 5 Inventive Example 26 15 1 1240 < 5 Inventive Example 27 15 1 1210 < 5 Inventive Example 28 27 4 1120 10 SUS444 29 51 25 500 <5 Type429 30 > 100 > 100 1480 < 5 Reference Example 1 31 > 100 > 100 1240 < 10 Reference Example 2 32 > 100 > 100 1400 < 10 Reference Example 3 (Note) Reference Example 1: W02003/004714 Invention Steel No. 3, Reference Example 2: Inventive Steel No. of Japanese Patent Laid-Open No. 2006-117985 No. 7, Reference Example 3: Invention Steel No. 5 098107277 23 200946694 of Japanese Patent Laid-Open No. 2000-297355. Fig. 1 is an explanatory diagram of a thermal fatigue test piece. Fig. 2 is an explanatory diagram of temperature and restriction conditions in the thermal fatigue β test. Figure 3 is a graph showing the effect of non-Cu content on thermal fatigue characteristics. Figure 4 is a graph showing the effect of A1 content on oxidation resistance (weight gain by oxidation). Fig. 5 is a graph showing the effect of the A1 content on the oxidation resistance (spoiling of amounts of scale). Fig. 6 is a graph showing the influence of the Si content on the oxidation resistance (the amount of rust peeling). Figure 7 is a graph showing the effect of Μη content on toughness (brittle fracture surface ratio). ‘ Figure 8 is a graph showing the effect of A1 content on the performance (brittle breaking rate). Ο Figure 9 is a graph showing the effect of Ti content on toughness (brittle breaking rate). 098107277 24

Claims

200946694 七、申請專利範圍： 1. 一種肥粒鐵系不鏽鋼，其含有C : 0. 015 mass%以下、 Si : 0· 5 mass%以下、Μη : 0. 5 mass%以下、P : 0. 04 mass% 以下、S : 0. 006 mass%以下、Cr : 16〜20 mass%以下、N : 0· 015 mass%以下、Nb : 0. 3〜0. 55 mass%、Ti : 0. 01 mass% 以下、Mo : 0. 1 mass%以下、W : 0. 1 mass%以下、Cu : 1. 0 〜2. 5 mass%、A1 : 0· 2〜1. 2 mass%，剩餘部分由Fe及不可 φ 避免之雜質而構成。 2. 如申請專利範圍第1項之肥粒鐵系不鏽鋼，其中，除上述之成分組成之外，更包含自B : 0. 003 mass%以下、 REM : 0· 08 mass%以下、Zr : 0. 5 mass%以下、V : 0. 5 mass% r 以下、Co : 0· 5 mass%以下及Ni : 0. 5 mass%以下之中所選 * 擇之1種或2種以上。200946694 VII. Patent application scope: 1. A ferrite-rich iron-based stainless steel containing C: 0.105 mass% or less, Si: 0·5 mass% or less, Μη: 0.5 mass% or less, P: 0. 04 Mass% or less, S: 0. 006 mass% or less, Cr: 16 to 20 mass% or less, N: 0·015 mass% or less, Nb: 0. 3 to 0. 55 mass%, Ti: 0.101 mass% The following, Mo: 0.1% mass% or less, W: 0.1 mass% or less, Cu: 1. 0 to 2. 5 mass%, A1: 0·2~1. 2 mass%, the remainder is Fe and not φ is formed by avoiding impurities. 2. For example, the ferrite-based iron-based stainless steel of the first application of the patent scope includes, in addition to the above-mentioned component composition, more than B: 0.003 mass% or less, REM: 0·08 mass% or less, Zr: 0 5 mass% or less, V: 0.5 mass% r or less, Co: 0·5 mass% or less, and Ni: 0. 5 mass% or less selected one or two or more.

25 09810727725 098107277