1240008 玖、發明說明： 【發明所屬之技術領域】 本發明是有關於-種不錢鋼，特別是一種肥粒鐵系不 錄鋼。 【先前技術】 近年不錄鋼因經濟的發展，生活水平的提高而被大量 使用，然而，用於製造使用時有高度潔淨需求之器材，例 如食品機器、流理台、醫療機器等方面之具備一定程度之 抗菌性的不錢鋼材，其需求亦隨著經濟發展、生活水^的 =高而日漸增加；近來，更因腸病毒、sars等傳染病的 肆虐影響’以具抗菌功能之不錄鋼材所製成的產品，更蔚 為保健重要趨勢，因此，研究發展具備有抗菌性的不錄鋼 材’即成為業者努力的方向之一。 —般使不_具備有-定程度的抗g性的作法，是採 用_、鑛膜，或是塗佈的方式，選用例如銀、銅、鉻、 鈦錄等金屬或其合金，在不錢鋼表面鑛覆一薄層，而藉 此等金屬的抗菌性較不錢鋼為優，以達到抗菌之目的，^ 如曰本特開平8·_5號專利案、w號專利案即揭 示此類技術手段。 ’ 然而’此種在不錄鋼表面錢覆—可抗菌之金屬薄層的 方式，雖然紐時間内可以達到抗菌的要求，可是，該 :之金屬薄層會隨著使用而逐漸磨耗、剝落，而： 長期的抗菌功效。 $付 鑒於上述在不錢鋼表面鍍覆一可抗菌之金屬薄層無法 、〗長期抗菌目的的缺點，許多專利提出直接將可抗菌的 ”屬，例如銅、銀等加入不銹鋼的組成中，而達到抗菌的 目例如中華民國第459057號專利案是將銀加入不銹鋼 的、、且成中，日本特開平9_170053號專利案等則是將銅加入 不銹鋼的組成中，而達到抗菌的目的。 上述專利雖然可以改善鍍覆金屬薄層無法長期抗菌的 缺點，但是由於添加了原本並不存在於不銹鋼組成中的大 ΐ的銅、銀等元素，致使在實際生產流程中面臨無法兼顧 其他性質之問題，例如加銅之後其熱加工性劣化之問題。 因此，如何研究改善不銹鋼的組成，使其不但能達到 抗菌的首要目的，同時仍具備有優良的熱加工特性，使該 抗菌鋼材能應用於實務生產製造層面，此亦為本發明之主 要目的。 【發明内容】 因此，本發明之目的，即在提供一種同時具有抗菌以 及優良的熱加工性的肥粒鐵系不銹鋼。 本發明之一種具有良好熱加工性及抗菌效果之肥粒 鐵系不銹鋼，包含一重量百分比介於〇 〇〇1至01之間的 碳元素、一重量百分比介於0.2至1.0之間的矽元素、一 重量百分比介於0.001至1_0之間的錳元素、一重量百分 比介於11·〇至20·0之間的鉻元素、一重量百分比介於〇 〇〇1 至0.1之間的氮元素、一重量百分比介於1〇至3·5之間的 銅元素、一平衡之鐵元素，及多數於煉鋼過程中不可避免 之微量元素；該各元素的成分是使得下列之一計算沃斯田 1240008 鐵相值（γ ph ; r -phase)的公式值最高為5〇，該公式是^ Ph=420x %c-11.5x %Si+7x %Mn+23x %Ni-11.5x /^Cr—12x %m〇+9x %Cu—49x %Ti—52x %Al + 470x / N + 189，且該肥粒鐵系不銹鋼是在一熱軋製程之後至少 實施一溫度範圍在700°C至850°C的退火製程，使組織中之 昌銅相析出。 本發明之功效在於提供一種具有抗菌效果的肥粒鐵 系不銹鋼，同時具有優良的熱加工性，而不會在熱軋時產 生邊裂，影響生產品質。 【實施方式】 有關本發明之前述及其他㈣内纟、特點與功效，在 以下配合參考圖式之較佳實施例的詳細說明中，將可清楚 的明白。 ，圖1，一般肥粒鐵系不銹鋼在高溫區的相變化， 可由圖1之祕平_圖所推算得知，例如在咖^、箱 =重量百分比為16%時’將由肥粒鐵相轉變為肥粒鐵相病 斯田鐵相兩相共存，此時，因兩相的強度不-，而導彩 :軋延時易沿著兩相界面產生裂紋，導致熱加工性之似 -,.U 刀双，一般是選用銀或鄭 不符=一戶:的，而銀由於材料成本遠較伽 加可以達到鋼材抗菌之功效，二 =:雖然， 穩定元素，添加銅會使得沃斯田鐵、5疋'夭斯田鐵相 斯田鐵相比例增加，而不利 !24〇〇〇8 鬲溫軋延。 、，因此，本發明一種具有良好熱加工性及抗菌效果之肥 /、载系不錄鋼，即疋透過成分設計，使添加銅之肥粒鐵系 不鱗鋼能以圖丨之鐵一鉻平衡相圖為根據，藉由公式預估 在高溫時沃斯田鐵相的比例，使其能兼具抗菌性與熱加工 性。由此，可得出本發明一種具有良好熱加工性及抗菌效 果之肥粒鐵系不銹鋼準確預測肥粒鐵系不銹鋼之沃斯田 鐵相（最大比例的計算公式為 γΡΗ=42〇χ %c -Π.5Χ %Si+7x %Mn+23x %Ni-11.5x %Cr-12x % Μο+9χ %Cu—49x %Ti-52x %Α1+ 470χ %N + 189，其 中，％c表示含碳元素之重量百分比，％Si表示含矽元素 之重S百分比，％Mn表示含錳元素之重量百分比， 表示含鎳元素之重量百分比，％Cr表示含鉻元素之重量百 分比，表示含鉬元素之重量百分比，％Cu表示含鋼 元素之重量百分比，％Ti表示含鈦元素之重量百分比，％ A1表示含鋁元素之重量百分比。並，控制碳（c )元素的 重里百为比介於0.001與0.1之間，石夕（Si)元素的重量百 分比介於0.2與1.0之間，猛（Μη)元素的重量百分比介 於o.ool與ι·ο之間，鉻（c〇元素的重量百分比介於11〇 與20.0之間’氮（Ν)元素的重量百分比介於〇· 〇〇1與〇1 之間’銅（Cu)元素的重量百分比介於1_〇與3.5之間， 多數於煉鋼過程中不可避免之微量元素，及平衡之鐵元 素，該些微量元素至少包含鉬（Mo )、鈦（Ti)、鋁（A1)、 小於150ppm的硫（S)、重量百分比小於〇·〇6的磷（p) 8 1240008 等且控制r ph最鬲為5〇，同時，在冶煉過程中，熱軋製 7後至最終成品之間，含上述組成之鋼材至少實施一次 :〇 C至850 C之間的退火製程，使組織中富銅相可析出而 凡成本务％ ’即具有良好熱加卫性及抗g效果之肥粒鐵系 不、秀鋼+但可藉上述組成與^ ph相值控制使其具有良好 的…、加工性，同時，藉析出的富銅相而可達到抗菌的功效。 /炭為沃斯田鐵相之強穩定元素，但同時其重量百分比 Γ7易使鋼材耐|虫性降低，且熱間加工性亦會變差，因此 本例控制添加碳（C)元素介於0.001%肖0.1%之間。同 時’在不銹鋼精煉過程中’必須以料為脫氧劑進行脫氧， 因此必須有一預定之重量百分比，但是矽含量太高時會使 其中的銘含Ϊ相對升高’反而會造成硬質介在物殘留，而 不利後、、’i加工製私，因此矽（Si)含量比控制介於0 與 1.0%之間。 鉻（Cr )的主要作用為抗姓，但同時為了原料成本考 夏，因此添加之比例介於Π%與20%之間。而，氮（N)、 猛（Μη)為沃斯田鐵相之穩定元素，太高或是太低均不利 於T ph的控制，因此分別控制其含量介於〇.〇〇1%至^ %，及 0.001% 至 1.0%。 由於鋼材中不論添加銅或銀至大於預定比例之後，均 具有抗菌的功效，而由於銀之成本較銅高出許多，因此本 發明具有良好熱加jl性及抗菌效果之肥粒鐵系不錄鋼為了 抗菌效果與成本的考量，故選擇銅添加1.0%至3.5%之間 以達到抗菌的功效。 1240008 中，作為實驗組，而取第—支玻璃試管試液50/zl加入第 =支玻賴管巾，料對照組。於實驗組與對照組每根試 管中取50#卜均勻塗抹在固態營養基上，其中試管放置 37度水恆溫槽24小時，將水怪溫槽中實驗組與對照組每 根試管再取5_’均勾塗抹在固態營養基上將其放置 於37度培養箱中24小時，觀察結果，數菌並計算抑菌率， 抑菌率須大於99%以上方稱為有抗菌效果，其中，抑菌率 =(起始接種龍_24小時後菌數）*刚/起始接種菌數；而實 驗菌種是選自曰常生活中常見的大腸桿菌、金黃色葡萄球 菌作為菌種進行實驗。 、由表-所示之實際實驗結果可知，本發明具有良好熱 加工性及抗菌效果之肥粒鐵系不銹鋼之試驗片（即表中: 發明鋼）％以不同溫度之時效熱處理後，對大腸桿菌的抑 菌率達100%，而-般含銅量較低之肥粒鐵系不錢鋼（即 表中之比較鋼）則幾乎不具任何抑菌率，可知本發明具有 良好熱加工性及抗菌效果之肥粒鐵系不銹鋼具有抗菌的功 效01240008 (1) Description of the invention: [Technical field to which the invention belongs] The present invention relates to a kind of nonferrous steel, especially a ferrous grain iron-based non-recording steel. [Prior technology] In recent years, steel has not been widely used due to economic development and improvement of living standards. However, it is used to manufacture equipment that requires high cleanliness during use, such as food machines, fluid tables, medical equipment, etc. The demand for a certain degree of antibacterial non-ferrous steel is also increasing with the economic development and living water ^ = high; recently, due to the raging effects of enteroviruses, sars and other infectious diseases, it is not recorded with antibacterial function. Products made of steel are more important for health care. Therefore, research and development of non-recording steel with antibacterial properties has become one of the efforts of the industry. —Generally, the method of not having a certain degree of resistance to g is to use _, mineral film, or coating methods, such as silver, copper, chromium, titanium and other metals or their alloys. The surface of the steel is covered with a thin layer, and the antibacterial properties of these metals are better than that of steel, in order to achieve the purpose of antibacterial. ^ Such as the Japanese Patent Publication No. 8-5, patent w Technical means. 'However', this method of covering the surface of the steel with a thin layer of antibacterial metal, although it can meet the antibacterial requirements within a short time, however, the thin metal layer will gradually wear away and peel off with use. And: Long-term antibacterial effect. In view of the above-mentioned shortcomings that it is impossible to plate a thin layer of antibacterial metal on the surface of stainless steel, long-term antibacterial purposes, many patents propose to directly add antibacterial "genus, such as copper and silver, to the composition of stainless steel, and To achieve antibacterial purposes, for example, the Patent No. 459057 of the Republic of China added silver to stainless steel, and it was formed, and Japanese Patent Application No. 9_170053, etc., added copper to the composition of stainless steel to achieve the purpose of antibacterial. Although it can improve the shortcomings that the plated metal layer cannot be antibacterial for a long time, due to the addition of elements such as copper and silver that do not exist in the stainless steel composition, it faces the problem of being unable to take into account other properties in the actual production process. For example, the hot workability deteriorates after copper is added. Therefore, how to study and improve the composition of stainless steel so that it can not only achieve the primary purpose of antibacterial, but also have excellent hot working characteristics, so that the antibacterial steel can be used in practical production Manufacturing level, this is also the main purpose of the present invention. [Summary] Therefore, the purpose of the present invention That is, a fertile iron-based stainless steel having both antibacterial and excellent hot workability is provided. A ferrous iron-based stainless steel with good hot workability and antibacterial effect according to the present invention includes a weight percentage of 0.001 Carbon element between 01 and 01, silicon element with a weight percentage between 0.2 and 1.0, manganese element with a weight percentage between 0.001 and 1_0, and a weight percentage between 11.0 and 20.0 Chromium element, a nitrogen element with a weight percentage between 0.001 and 0.1, a copper element with a weight percentage between 10 and 3.5, a balanced iron element, and most of the steelmaking process Inevitable trace elements; the composition of each element is such that one of the following formulas to calculate the iron phase value (γ ph; r-phase) of Vostian 1240008 is up to 50, the formula is ^ Ph = 420x% c -11.5x% Si + 7x% Mn + 23x% Ni-11.5x / ^ Cr—12x% m〇 + 9x% Cu—49x% Ti—52x% Al + 470x / N + 189, and the ferrous iron-based stainless steel After a hot rolling process, at least an annealing process in the temperature range of 700 ° C to 850 ° C is performed to make the structure The copper phase is precipitated. The effect of the present invention is to provide a ferrous iron-based stainless steel with antibacterial effect and excellent hot workability without causing edge cracks during hot rolling and affecting production quality. [Embodiment] Related The foregoing and other characteristics, features, and effects of the present invention will be clearly understood in the following detailed description of the preferred embodiments with reference to the drawings. Figure 1, general ferrous iron-based stainless steel in the high temperature region The phase change can be inferred from the secret flat figure in Figure 1. For example, when the coffee weight is 16% by weight, the iron phase will be changed from the iron phase to the iron phase. At this time, because the strength of the two phases is not-, the guide color: the rolling delay is easy to generate cracks along the interface of the two phases, resulting in hot workability similar to-,. U knife double, usually silver or Zheng is not equal = one household: Because silver has a much higher material cost than Galga, it can achieve the antibacterial effect of steel. Second =: Although, stabilizing elements, the addition of copper will increase the ratio of Vostian Iron and 5 疋 '铁 斯 田 铁 相 斯 田 铁. And unfavorable! 24000 鬲 warm rolling. Therefore, the present invention has a fertilizer with good hot workability and antibacterial effect. The load-bearing non-recording steel, that is, the permeation component design, enables the ferrous grain iron-based non-scale steel with copper to add iron-chromium as shown in the figure. The equilibrium phase diagram is based on a formula that estimates the proportion of the Vosstian iron phase at high temperatures, enabling it to have both antibacterial and hot workability. From this, it can be obtained that the ferrous iron-based stainless steel with good hot workability and antibacterial effect according to the present invention accurately predicts the ferrous phase iron phase of the ferrous iron-based stainless steel (the calculation formula for the maximum ratio is γPΗ = 42〇χ% c -Π.5χ% Si + 7x% Mn + 23x% Ni-11.5x% Cr-12x% Μο + 9χ% Cu—49x% Ti-52x% Α1 + 470χ% N + 189, where% c represents a carbon-containing element % By weight,% Si means the percentage of weight S containing silicon,% Mn means the percentage by weight of manganese, the weight percentage of nickel,% Cr means the weight percentage of chromium, the weight percentage of molybdenum, % Cu indicates the weight percentage of steel-containing elements,% Ti indicates the weight percentage of titanium-containing elements, and% A1 indicates the weight percentage of aluminum-containing elements. Also, the weight percent of the control carbon (c) element is between 0.001 and 0.1 The weight percentage of Shi Xi (Si) element is between 0.2 and 1.0, the weight percentage of manganese (Μη) element is between o.ool and ι · ο, and chromium (the weight percentage of element c is between 11 and 10). The weight percentage of 'nitrogen (N) element between 20.0 and 0. 0 〇1 and 〇1 'The weight percentage of copper (Cu) element is between 1_〇 and 3.5, most of the trace elements inevitable in the steelmaking process, and balanced iron elements, these trace elements contain at least Molybdenum (Mo), titanium (Ti), aluminum (A1), sulfur (S) less than 150 ppm, phosphorus (p) 8 1240008 in weight percentage less than 0.06, etc. and control r ph to be at most 50, at the same time, In the smelting process, after hot rolling 7 to the final product, the steel with the above composition is subjected to the annealing process at least once: 0C to 850 C, so that the copper-rich phase in the organization can be precipitated and the cost is% Fertile iron with good thermal defense and anti-g effect, Xiugang +, but can be controlled by the above composition and ph phase value to have good ..., processability, and at the same time by the precipitated copper-rich phase It can achieve antibacterial effect. / Charcoal is a strong stabilizing element of the iron phase of Wastian, but at the same time its weight percentage Γ7 will easily reduce the steel's resistance to insects, and the thermal processability will also be poor, so this example controls the addition of carbon. (C) The element is between 0.001% and 0.1%. At the same time, 'in the stainless steel refining process' must The material is used as a deoxidizing agent for deoxidation, so it must have a predetermined weight percentage, but when the silicon content is too high, the inscription will be relatively increased. 'Rather, it will cause the hard intermediary residues, which will be unfavorable.' Private, so the control of silicon (Si) content ratio is between 0 and 1.0%. The main role of chromium (Cr) is to resist surnames, but at the same time for the cost of raw materials, so the proportion of addition is between Π% and 20% However, nitrogen (N) and manganese (Μη) are the stable elements of the Vostian iron phase. Too high or too low are not conducive to the control of T ph, so the content is controlled to be between 0.001%. To ^%, and 0.001% to 1.0%. Since copper or silver is added to steel more than a predetermined ratio, it has antibacterial effect, and because the cost of silver is much higher than copper, the ferritic iron with good heat addition and antibacterial effect is not recorded in the present invention. For the consideration of antibacterial effect and cost of steel, copper is selected to add between 1.0% and 3.5% to achieve antibacterial effect. In 1240008, as the experimental group, the first glass test tube test solution 50 / zl was added to the third glass tube towel, and the control group was used. Take 50 # of each test tube in the experimental group and the control group and apply it evenly on the solid nutrient base. The test tube is placed in a 37 ° C water bath for 24 hours. Each test tube in the experimental and control baths in the water bath is taken 5_ ' All hooks are smeared on a solid nutrient base and placed in a 37 ° incubator for 24 hours. Observe the results. Count the bacteria and calculate the bacteriostatic rate. The bacteriostatic rate must be greater than 99%. Rate = (starting inoculation dragon_24 hours after bacteria inoculation) * number of inoculation bacteria in the beginning; and the experimental strain is selected from common E. coli, Staphylococcus aureus as a strain for experiments. According to the actual experimental results shown in Table-, it can be seen that the test piece of the ferrous iron-based stainless steel with good hot workability and antibacterial effect according to the present invention (ie, in the table: the invention steel) is subjected to aging treatment at different temperatures for the large intestine. The bacteriostatic rate of Bacillus bacilli reaches 100%, and the ferrous grain iron steel with low copper content (comparative steel in the table) has almost no bacteriostatic rate. It can be seen that the invention has good hot workability and Antibacterial effect of ferrous iron stainless steel has antibacterial effect0
1240008 —------ — 2.46% ---~---- 3.04% 比 0.02% ------. 較 鋼 0.1% j〇〇%_ 100% 再由表一對金更色葡萄球菌之抑菌率實驗，可知本發 月一有良好熱加工性及抗菌效果之肥粒鐵系不銹鋼之試驗 片廿(即表中之發明鋼）％以不同溫度的時效熱處理後，對 金黃色葡萄球菌的抑菌率《 100%，且-般含銅量較低 之肥粒鐵系不銹鋼（即表中之比較鋼）抑菌率幾乎為零， 可传知本發明具有良好熱加卫性及抗菌效果之肥粒鐵系不 銹鋼的確具有優異的抗菌效果。 、1240008 --------2.46% --- ~ ---- 3.04% better than 0.02% ------. 0.1% more steel than j〇〇% _ 100% The bacteriostatic rate test of staphylococcus shows that the test piece of ferrous iron-based stainless steel with good hot workability and antibacterial effect (this is the invention steel in the table)% was treated with aging at different temperatures. The bacteriostatic rate of Staphylococcus aureus "100%, and-generally low ferrous grain iron-based stainless steel (ie, the comparative steel in the table) has a nearly zero bacteriostatic rate. It can be known that the present invention has good thermal protection Ferrous iron-based stainless steel with excellent performance and antibacterial effect does have excellent antibacterial effect. ,
【表二】萄球菌之抑菌率測就μ早 勒‘者 I田 二，：~~ΤΖ~Ζ7~~~~~ ------- 參閲表三，本發明具有良好熱加工性及抗菌效果之肥 粒鐵系不_在具有優異之抗菌效果的前提之下，由 Ph值均限制最高為5G，可減少沃斯田鐵相於純溫度區間 12 1240008 殘留，而在熱軋延後觀察試片表面並無邊裂缺陷的產生； 其他T ph值大於5 0的肥粒鐵系不銹鋼（即表中之比較鋼） 則產生邊裂缺陷，兩相比較後可得知，本發明具有抗菌效 果的肥粒鐵系不銹鋼在具有優異之抗菌效果的前提之下， 確實具有優良的熱加工性。 【表三】熱軋延測試結果 碳（C) 矽（Si) Ml ( Μη ) 鉻（Cr) 銅（Cu) 7 Ph 品質狀況 發 0.02% 0.21% 0.35% 16.10% 1.98% 49.1 無邊裂 明 0.03% 0.27% 0.46% 16.01% 2.07% 47.9 無邊裂 鋼 0.02% 0.20% 0.40% 16.24% 2.40% 49.3 無邊裂 0.12% 0.22% 0.44% 16.06% 2.00% J00.1 有邊裂 比 0.04% 0.27% 0.35% 16.03% 2.07% 58.5 有邊裂 較 0.12% 0.23% 0.52% 15.80% 2.46% 107.6 有邊裂 鋼 0.04% 0.24% 0.35% 16.02% 2.64% 64.6 有邊裂 0.11% 0.24% 0.45% 15.84% 3.04% 109.7 有邊裂 綜所上述，本發明具有良好熱加工性及抗菌效果之肥 粒鐵系不銹鋼是確實依據實驗研究修正y ph的計算公式， 同時詳細研究不銹鋼中主要成分如碳、矽、錳、鉻、銅、 氮等元素之重量百分比及控制r ph值，而可同時具備有優 異的抗菌性以及熱加工性，確實達到本發明之目的。 惟以上所述者，僅為本發明之較佳實施例而已，當不 能以此限定本發明實施之範圍，即大凡依本發明申請專利 範圍及發明說明書内容所作之簡單的等效變化與修飾，皆 應仍屬本發明專利涵蓋之範圍内。 13 1240008 【圖式簡單說明】 圖1是一鐵一鉻平衡相圖，說明本發明具有良好熱加 工性及抗菌效果之肥粒鐵系不銹鋼之研究預測依據。 14[Table 2] The bacteriostatic rate of staphylococcus was measured as early as the early one, Tian Tian: ~~ ΤTZ ~ Z7 ~~~~~ Refer to Table 3, the invention has good thermal processing Fertilizer and iron with no antibacterial effect_Under the premise of excellent antibacterial effect, the maximum value of Ph is limited to 5G, which can reduce the residue of Vostian iron phase in the pure temperature range 12 1240008, and in hot rolling Delayed observation of the surface of the test piece did not show the occurrence of edge crack defects; other ferritic iron-based stainless steel with a T ph value greater than 50 (ie, the comparative steel in the table) generated edge crack defects. After comparing the two, it can be seen that the present invention The ferrous iron-based stainless steel with antibacterial effect has excellent hot workability under the premise of having excellent antibacterial effect. [Table 3] Hot rolling test results Carbon (C) Silicon (Si) Ml (Mn) Chromium (Cr) Copper (Cu) 7 Ph Quality condition 0.02% 0.21% 0.35% 16.10% 1.98% 49.1 Boundless crack 0.03% 0.27% 0.46% 16.01% 2.07% 47.9 Borderless steel 0.02% 0.20% 0.40% 16.24% 2.40% 49.3 Borderless 0.12% 0.22% 0.44% 16.06% 2.00% J00.1 Edge cracking ratio 0.04% 0.27% 0.35% 16.03% 2.07% 58.5 Edge crack is 0.12% 0.23% 0.52% 15.80% 2.46% 107.6 Edge crack steel 0.04% 0.24% 0.35% 16.02% 2.64% 64.6 Edge crack 0.11% 0.24% 0.45% 15.84% 3.04% 109.7 Edge crack In summary, the ferritic iron-based stainless steel with good hot workability and antibacterial effect of the present invention is indeed based on experimental research to modify the calculation formula of y ph. At the same time, the main components of stainless steel such as carbon, silicon, manganese, chromium, copper, The weight percentage of nitrogen and other elements and the control of the r ph value can simultaneously have excellent antibacterial properties and hot workability, and indeed achieve the object of the present invention. However, the above are only the preferred embodiments of the present invention. When the scope of implementation of the present invention cannot be limited by this, that is, the simple equivalent changes and modifications made according to the scope of the patent application and the content of the invention specification, All should still fall within the scope of the invention patent. 13 1240008 [Brief description of the diagram] Fig. 1 is an iron-chromium equilibrium phase diagram, illustrating the research and prediction basis of the ferritic iron-based stainless steel with good thermal workability and antibacterial effect of the present invention. 14