201006939 六、發明說明： 【發明所屬之技術領域】 本申請案係主張2008年8月6曰及2009年3月4曰於韓國 智慧財產局所提出之韓國專利申請第2008-77067號及第 2009-18464號之優先權，其所揭露之内容均併入本發明以 供參酌》 本發明係關於一種具優異切割性（即機械特性）之環保 無鉛快削鋼及其製作方法。特別是，本發明尤指一種環保 無鉛快削鋼，其具有下述特性：1)添加適量之Ti、Cr、N、 或相似元素以形成非金屬内容物及沉澱物，2)於其他成分 中具有Mn/S且其比例係調整為3.5或以上，3)氧總量（即所 有的氧）係限制在300 ppm或以下，以及4)調整MnS包含物 之數量使於一線材親鋼方向之剖面上，每單位平方公厘具 有300至1，000個面積為5gm2或以上之MnS内含物。藉此， 本發明之快削鋼具有較佳之切割性（即機械特性）以及熱輥 性。 【先前技術】 一般而言，快削鋼係指一種透過將鋼材材料機械特性 (即一般所謂之切割性）提升至最大值所製得之鋼材。快削鋼 係普遍用於做為如軸承或辦公自動設備切割部、可適用於 自動車之油壓部件之元件、印表機、或其相似裝置、及其 用途等應用之材料，因此，對於快削鋼之需求係持續不斷 增加中。 201006939 快削鋼基本上具有良好之切割性，特別是機械切割 性；此外，於本技術領域中，可藉由添加不同合金元素或 於内部形成内含物，以提升鋼材之切割性。非金屬内含物 特別可用於做為提升切割性之材料，且MnS係為一種最眾 所皆知之非金屬内含物。 快削鋼之切割性可透過控制MnS之尺寸、組成、外形 及分散度來調整。更詳細而言，當鋼材材料係使用如搁板 (即齒軌）等機械裝置截切時，於工具尖端及鋼材材料相互碰 # 觸等部位，非金屬内含物（如MnS)可做為應力集中源，且於 非金屬内含物及基材間之介面所產生之孔隙可加速裂縫生 成，藉此可減少操作切割時所需之力度。 因此，為了提升快削鋼之切割性，基本上，1)需維持 大量之MnS，2) MnS必須隨機分布，以及3) MnS需具有較 大尺寸且較佳為球狀。 於快削鋼中，MnS外形係依照連鑄鋼液分配器中之氧 含量而改變，且可分為三種形式：球狀（第I型）；條狀（第II φ 型）；以及不規則狀（第III型）。 目前已知當MnS較接近球狀（第I型）時，其切割性係更 加提升。若鋼液分配器中總氧量（T[0])達數百ppm高時，在 高溫下MnS會凝固在熔融態鋼材中，且在去氧製程中結晶 成一複合硫化物，如Mn(0,S)。同時，當MnS較接近條狀（第 II型）時，若鋼液分配器中總氧量（τ[ο])相對較低，如數十 ppm，於凝固時，在炼融鋼材狀態中之MnS不會結晶，但卻 會沿著顆粒最初之介面釋出，因而造成在鋼材材料熱輥軋 5 201006939 過程中，MnS容易在輥鋼方向上延伸，而導致材料異向性 劣化。 在除了快削鋼外之一般鋼材的凝固過程中，會產生條 狀（第II型）結構，且由於條狀結構會造成鋼材機械特性顯著 劣化，故許多研究嘗試要減少s的含量至數ppm以下，以維 持MnS不會在冶鍊過程中析出。 最後’具有不規則狀（第ΠΙ型）之MnS，其特徵在於當 鋼液分配器中總氧量T[〇]低至數ppm且溶融態紹成分含量 較高時，在高溫下所產生之不規則狀MnS係為主要之!^!^ 單一内含物’且目前已知不規則狀MnS會以有稜角的狀態 存在於鋁去氧鋼材中。 在快削鋼之技術中’目前已提出一種將如C、Si、Mn、 S、P、Nb、Ο等元素限制在特定範圍且將做為冶鍊組織（fine tissue)之多邊形鐵素體（p〇iyg〇nai ferrjte)之面積比例限制 在5%或以上之技術。然而，即便添加大量如Nb、M〇、Zr 等昂貴合金元素，此技術仍無法明確提出鐵合金於快削鋼 中所達成之功效。此外’雖然此技術將多邊形鐵素體之面 積比例限制在一特定範圍，但此技術卻未提供其大致測量 方法。 於另一快削鋼之技術中，係添加特定量之C、Si、Μη、 S、Ο、Bi等’且於一線材輥鋼方向之剖面上每單位平方公 厘之Bi包含物之含量、以及Bi含量比例係限制在一特定數 值中。然而’雖然此技術限制Bi包含物數量及Bi含量比例， 實際上快削鋼製作時，比例卻難以控制。此外，此技術特 201006939 徵在於添加0.005 wt%或以下之氧，但這樣含氧量卻難以得 到一具有良好切割性之高氧快削鋼，以控制MnS具有球狀 外型，換言之，即第I型。 於再一有關快削鋼製作之技術中，係關於一種含硫連 鑄快削鋼，其具有等同於以習知鑄製方法所製得之快削鋼 具有相同程度之切割性。此含硫連鑄快削鋼之特性在於， 其包含特定含量之碳（C)、錳（Μη)、磷（P)、硫（S)、氮（N)、 及氧（02)，且MnS包含物之平均尺寸係為50/zm2或更小。然 〇 而，此技術雖揭露MnS含量，但鮮少提到顆粒尺寸，且未 提供MnS外型對於切割性影響之說明。 於另一有關快削鋼之技術，其特徵在於以碳（C)、錳 (Μη)、磷（P)、硫（S)、氮（N)、及氧（0)做為基本成分，同時 Si之含量係限制在0.1 wt%以下，Α1含量則限制在0.009 wt% 以下，N總量係介於20 ppm至150 ppm範圍内，且氧基包含 物係為50%以上。然而，若考量到實際應用上，此技術難以 精破測量快削鋼中氧基包含物之重量，且此技術在特定範 ^ 圍中係受限為無法測量的數值，故此技術必定具有有效性 及實用性等問題。 於再一有關快削鋼之技術，係為一種Bi-S基快削鋼之 製作方法，其使Bi-S基快削鋼具有極佳物理特性，並使奥 式體（austenite)顆粒尺寸調整在一特定尺寸以提升高溫延 展性。換言之，此Bi-S基快削鋼係包含0.05 wt%至0.15 wt% 之碳（C)、0.5 wt%至 2.0 wt%之錳（Μη)、0.15 wt%至 0.40 wt% 之硫（S)、0·01 wt%至 0.10 wt%之磷（P)、0.003 wt%至 0.020 7 201006939 wt%之氧（Ο)、0.03 wt%至 0.30 wt%之叙：（Bi)、0.01 wt%或以 下之矽（Si)、0.0009 wt%或以下之鋁（Al)、以及Fe與不可避 免（即無法除去）之不純物之平衡成分。此具有MnS且吸附有 鉍之MnS基包含物之剖面部分係佔Bi-S基快削鋼總剖面之 0.5%至2.0%，而鉍之剖面部分則佔Bi-S基快削鋼總剖面之 0.030%至0.30%。然而，此有關Bi-S基快削鋼之技術，卻未 提供如何控制如本發明所述之MnS組成之相關方法。 【發明内容】 本發明之主要目的係在提供一種快削鋼，其可避免（或 解決）本技術領域之相關問題、或是本技術領域明顯存在之 未解決問題，且本發明所提供之快削鋼其符合環保規範（規 則），且具有極佳切割性及熱親特性、及其他相似特性。 本發明之一態樣係提供一種快削鋼，其包括：0.03 wt% 至 0.13 wt%之礙（C)、0.1 wt%或以下之石夕（Si)、0·7 wt%至 2.0 wt%之猛（Μη)、0·05 wt%至 0.15 wt%之填（P)、0·2 wt%至 0.5 wt%之硫（S)、0.001 wt%至 0.01 wt%之棚（B)、0.1 wt%至 0.5 wt%之鉻（Cr)、0.003 wt%至 0.2 wt%之鈦（Ti)、0.005 wt%至 0.015 wt%之氮（N)、0.03 wt%或以下之氧（O)、以及鐵與不 可避免的不純物之平衡成分。於快削鋼線材輥鋼方向之剖 面上，每平方公厘（mm2)可具有300至1，000個顆粒尺寸為5 μ m2或以上之MnS内含物。其中，Μη與S間之重量比可為 Mn/S仝3.5。 201006939 本發明之另一態樣係提供一種快削鋼之製作方法，其 包括：以一超音波迷率通入氧氣至一於轉化爐中之金屬熔 融物以轉化冶鍊該金屬熔融物，且當游離氧在400 ppm至 1,000 ppm時停止氧氣吹煉；排放非去氧狀態之氧氣吹煉完 成金屬熔融物至盛鋼桶中；從該盛鋼桶轉移至精煉爐（LF) 中以加熱熔融鋼材，再進行LF冶鍊，直至於該金屬熔融物 中之游離氧密度範圍在1〇〇 ppm至200 ppm之間；使用一鋼 胚連鑄該熔融鋼材，以使當時間點等於冶鍊持續時間之i 〇〇/0 ❹ 至50%時，游離氧之密度為50 ppm至150 ppm ;以及將該鋼 胚維持在i，200°C至1，350°C之加熱爐中2至5小時，以輥軋該 鋼胚以形成一線材。其中，在連铸製程中，熔融鋼材可製 作成一塊鋼，其接下來可透過鋼胚輥軋而製作成一鋼胚， 且於此過程裝’快削鋼之製作方法可更包括：將該塊鋼維 持在l,250eC或以上溫度之加熱爐中4至10小時，以輥軋該塊 鋼以形成一鋼胚。 此快削鋼可包括：0.03 wt%至0.13 wt%之碳（c)、0.1 ❿ wt%或以下之矽（si)、0.7 wt。/。至 2.0 wt% 之猛（Μη)、0.05 wt% 至 0 15 wt%之磷（P)、0.2 wt%至 0.5 wt%之硫（S)、0.001 wt〇/o 至 0.01 wt°/。之硼（B)、o.1 wt%至 o.5 wt%之絡（Cr)、0,003 wt〇/o 至 0.2 wt%之鈦（Ή)、0·005 Wt%至 0,015 Wt%之氮（N)、0.03 wt%或以下之氧（〇)、以及鐵與不可避免不純物之平衡成 分。於線材輥鋼方向之别面上，每平方公厘（mm2)可具有300 至1，000個顆粒尺寸為或以上之MnS内含物。特別是’ 連鑄製程可使用一電磁攪拌器或一輕壓裝置，或是同時使 9 201006939 用該電磁攪拌器及該輕壓裝置進行，且Μη與S間之重量比 可為]VIn/S^；3.5。 為達成上述目的，本發明之發明人製作出一種快削 鋼，其係1)添加適量之Ti、Cr、N、或相似元素以形成非 金屬内容物及沉澱物，2)控制Mn/S，使其於其他成分中之 比例為3.5或以上，3)氧總量係限制在3〇〇 ppm或以下，以 及4)調整MnS包含物之數量，使於一線材親鋼方向之剖面 上每單位平方公厘具有300至1，000個面積為5/z m2或以上 之MnS内含物。 快削鋼中之MnS包含物外型係如圖i所示，同時，藉由 限制Ti、Cr、以及N等如上述之技術特徵，當凝固時可於顆 粒介面大量析出（如，沉澱）尺寸範圍為O-1/zm至5从m之（Cr, Ti) S基或（Cr，Ti) N基之細小沉殿物，如圖2所示。藉此，可 達到1)防止在機械操作時加工不易區域產生，以提升切割 性’以及2)提升鋼材材料之破裂韌性，以防止刀口積肩 (build-up edge，BUE)並克服刀刃碎片產生，以提升快削鋼 性能。因此，可延長器具的使用時間以及提升表面硬度。 接下來’將進一步更詳細地描述快削鋼之成分。 碳（C) · 〇·〇3 wt%至 0·13 wt% 碳係為形成碳化物之元素，以增加材料之強度及硬 度。碳係做為一部分珠光體（pearlite)而存在於快削鋼中， 其用於防止在切割鋼材材料時器具中產生BUE。若碳含 量少於0·03 w%，則材料硬度無法增加到一理想程度，而盈 法達到限制BUE生成之效果。同時，若碳（c)含量超過^ 201006939 W% ’則材料硬度會大幅度增加，反而造成器具使用時間縮 短。因此，在本發明一實施態樣中，碳（c)含量係限制在003 w0/〇至0.13 W%範圍内。 石夕（Si) : 〇,i wt%或以下 石夕（Si)係為材料中之元素之一，因其存在於生鐵或還原 劑中。矽除了會形成氧化物外，即所謂之Si〇2，矽（si)多為 亞鐵鹽之固溶體（s〇lid-s〇luted)，因此，已知碎並不會明顯 影響快削鋼之機械特性。然而，本發明之發明者實驗發現， ® 於高氧快削鋼中，若矽（Si)含量超過0· 1 w%，會產生Si〇2， 導致在機械操作快削鋼時會使器具使用壽命大幅縮短。因 此，本發明主要並未使用矽（si) ^然而，若考慮到可行性， 妙（Si)仍不可避免的存在於鐵合金、鐵礦石、及其類似物 中，故於本發明之一實施態樣中，快削鋼中石夕（Si)之含量係 調整在0.1 %或以下。 錳（Μη) : 0.7 wt%至 2.0 wt0/〇 猛（Μη)為形成非金屬包含物MnS必要合金元素之一， 馨 以提供鋼材材料機械特性β當錳（Μη)添加量為〇.7 w%或以 上’則可確保MnS包含物具有有效結晶性，並可達到在熱 輥過程中使鋼材表面缺陷減少之效果。若猛（Mn)含量超過 2.0 w%，鋼材材料硬度會降低，且器具之使用時間亦會縮 短。當錳（Μη)的含量範圍在0.7 w%至2.0 w%之間，部分猛 會與氧氣結合而形成ΜηΟ，其可做為在凝固製程中MnS生 成核，以加速球狀MnS包含物生成》 磷（P) : 0.05 wt%至 0.15 wt% 201006939 磷（P)為一種用以抑制BUE容易生成在切割器具前端之 元素之一。若磷（P)含量少於0.05 w%，幾乎無法產生抑制 BUE生成的效果，若磷（P)含量超過0.15 w%，BUE抑制效果 佳，但卻會造成鋼材材料硬度增加，而縮短切割器具使用 壽命。因此，於本發明之一實施態樣中，磷（P)之含量係限 制在0.05 wt%至0.15 wt%之範圍内。 硫（S) : 0.2 wt%至 0.5 wt°/〇 於快削鋼中，硫係用以於凝固過程中形成MnS包含 物。如上所述，MnS係用來提升鋼材材料之機械特性，進 而減少切割器具磨損並提升工作部件表面硬度，因此，MnS 於本發明中是非常重要之成分之一。基於上述目的，硫（S) 之添加量為0.2 wt%或以上。然而，本發明之發明者實驗顯 示，若硫（S)添加量過多，會導致網狀（如同網子一般）FeS於 顆粒介面沉澱。FeS非常脆弱且熔點低，容易造成熱輥特性 大幅劣化。同時，若硫含量超過其所需，會導致鋼材材料 表面缺陷增加，且同時造成鋼材材料硬度及延展性顯著劣 化。因此，硫（S)含量勢必不能超過0.5 wt°/〇。 硼（B) : 0.001 wt%至 0.01 wt% 蝴（B)係用以增加鋼材材料之淬火（quenching)特性。因 此，於本發明中，係添加10 ppm至100 ppm的蝴（B)。若棚（B) 的添加量不少於10 ppm，可能難以適當提升淬火特性；但 若硼（B)添加量超過100 ppm，雖可充分提高淬火特性，但 可能造成高溫延展性劣化而無法進行熱輥製程。因此，硼 (B)含量應有上述限制。 201006939 絡（Cr) : 〇·1 wt%至 0.5 wt0/〇 鉻（Cr)係為一種可擴大奥式體區域之元素之一。換言 之，鉻是為一必要成分且為一種便宜的一般合金元素同 時，即便鉻含量很大，鉻所形成之碳化物卻不會造成材料 萃化。添加Cr會形成顆粒較大之（Cr，Mn)s基非金屬包含 物。此外，添加Cr可防止非金屬包含物變形，亦可在輥軋 步驟中使包含物可均勻分布在材料中。於本發明之—實施 態樣中，鉻的添加可提升機械特性，且本發明之發明者實 驗證實，當鉻添加量少於0.1 % ,則無法產生提升機械特性 之效果’但當鉻添加量超過0.5 wt% ’機械特性則達到—個 上限，而不會再繼續增加。因此，鉻（Cr)的含量係限制在〇3 wt%至0.5 wt%範圍内。較佳為，鉻（Cr)添加量可為〇1 wt% 至 0.5 wt%。 欽（Ti) · 0.003 wt%至 〇·2 wt% 鈦（Ti)與氧（Ο)、氮（N)、碳（c)、硫（s)、氫（Η)、及相似 元素之任一種元素可展現極佳親合力，特別是當鈦用於去 氧反應、脫氮反應、脫硫反應、及相似反應時。此外，欽 (Ti)容易形成破化物及冶鍊出顆粒。本發明之相關實驗證 實’添加多於0.003 wt%的鈦（Ti)，冶鍊出的顆粒可大幅提 升機械特性。此外，添加Ti可提升可硬化性，以防止BUE 形成，藉此可提升機械特性。然而，倘若鈦（Ή)含量超過0.2 wt°/〇，提升機械特性之效果已達上限，反而因材料中Ti〇2 的形成造成切割裝置使用壽命縮短。因此，鈦（Ti)含量應限 13 201006939 制在0.003 wt%至0.2 wt%範圍内，較佳為0.008 wt%至0.15 wt% 0 H(N) : 0.005 wt%至 0.015 wt% 氮係為一種影響切割器具中BUE生成與切割物表面粗 糙度之元素之一。若氮（N)含量少於0.005 wt%，會造成BUE 生成增多且表面粗糙度劣化。當氮含量增加，BUE產生會 減少，但當氮（N)含量超過0.015 wt%，則模鑄完成之快削鋼 鋼材表面缺陷會增加，反而產生另一缺點。因此，本發明 中，氮（N)含量係限制在0.005〜1%至0.015评1°/〇範圍内。 氧（0) : 0.03 wt%或以下 氧（Ο)係在模鑄快削鋼的過程中，於模具中凝固熔融態 鋼材之最初步驟時，用於形成細小的MnO，而MnO係做為 MnS結晶之結晶核生成點。在此，所指的氧係為存在於模 铸完成鋼件（即鑄板）中之總氧量（T. [0])。如上所述，若氧 含量係為數十ppm或以下時，當熔融態鋼材凝固時，第II型 或第III型中之MnS可能會沉澱，且這樣型態的MnS會造成 快削鋼切割性（即機械特性）劣化。於本發明中，為了具有最 佳化之切割性，主要目的係產生第I型之MnS結晶，即所謂 之球狀MnS。實驗結果顯示，當氧含量提升，可有效結晶 產生球狀MnS，但若氧含量超過0.03 wt%，則如針扎、氣孔、 或相似孔洞之表面缺陷會大幅增加。因此，必須限制氧含 量之上限。 錳（Μη)與硫（S)之重量比：Mn/S23.5 201006939 除了調整成分含量外，為了使快削鋼在高溫下具有較 佳之延展性，需控制錳（Μη)及硫（S)間比例，以使Mn/S比例 為3.5或以上重量百分比。此比例係為了防止因混合猛（Μη) 及硫（S)所導致之FeS熱脆性，且必須確保Μη含量在特定數 值之上。特別是，若錳（Μη)及硫（S)比例低於3.5，會造成熱 輥特性劣化，而難以得到本發明所欲製得之快削鋼。 此外，於一線材輥鋼方向之剖面上，每平方公厘（mm2) 具有300至1,000個顆粒尺寸為5 # m2或以上之MnS。 Φ 快削鋼之切割性（即機械特性）係隨著鋼材中之非金屬 内含物MnS尺寸及分布而有所改變。一般而言，當MnS顆粒 較大且MnS含量較多時，鋼材材料具有較佳之切割性。經 本發明之發明人光學顯微鏡測量及切割性測試評估結果顯 示，當於一線材輥鋼方向（即L方向）之剖面上，每平方公厘 (mm2)具有300至1,000個顆粒尺寸超過5/z m2之MnS時，鋼材 材料之切割性最佳。當少於300個MnS時，因切割性較差容 易導致器具使用時間縮短，且亦會導致加工區域表面粗糙 _ 度劣化。同時，若MnS數目超過1，000，雖可增加器具之使 用壽命，但卻會造成鋼材加工性劣化（不良）。因此，MnS 數量較佳係控制在300至1,000範圍内。 接下來，請參考圖3，將詳細描述一種包含上述合金組 成物之快削鋼製作方法，其可適用於本發明。 轉化冶鍊： 首先，以超音波速率將氧氣通入一於轉化爐中之金屬 熔融物，以除去經空氣或爐渣而包含在金屬熔融物中之C、 15 201006939201006939 VI. Description of the Invention: [Technical Fields of the Invention] This application claims Korean Patent Application No. 2008-77067 and 2009- proposed by the Korea Intellectual Property Office on August 6, 2008 and March 4, 2009. Priority is made to the disclosure of the present invention for the benefit of the present disclosure. The present invention relates to an environmentally friendly lead-free quick-cut steel having excellent cutting properties (i.e., mechanical properties) and a method of making the same. In particular, the present invention particularly relates to an environmentally friendly lead-free fast-cutting steel having the following characteristics: 1) adding an appropriate amount of Ti, Cr, N, or the like to form a non-metallic content and precipitate, and 2) among other components. Having Mn/S and the ratio is adjusted to 3.5 or more, 3) the total amount of oxygen (ie, all oxygen) is limited to 300 ppm or less, and 4) adjusting the amount of MnS inclusions in the direction of a wire. In the cross section, there are 300 to 1,000 MnS contents having an area of 5 gm 2 or more per unit square mm. Thereby, the quick-cut steel of the present invention has better cutting properties (i.e., mechanical properties) as well as hot roll properties. [Prior Art] In general, a fast-cut steel refers to a steel obtained by raising the mechanical properties of a steel material (i.e., generally called cutting property) to a maximum value. The fast-cutting steel system is generally used as a material such as a bearing or office automatic equipment cutting part, a component that can be applied to a hydraulic component of an automatic vehicle, a printer, or the like, and a use thereof, and therefore, The demand for steel cutting continues to increase. 201006939 Fast-cut steel basically has good cutting property, especially mechanical cutting property; in addition, in the technical field, the cutting property of steel can be improved by adding different alloying elements or forming inclusions inside. Non-metallic inclusions are especially useful as materials for improved cutting, and MnS is one of the most well-known non-metallic inclusions. The cutting properties of the fast-cut steel can be adjusted by controlling the size, composition, shape and dispersion of the MnS. In more detail, when the steel material is cut by a mechanical device such as a shelf (ie, a rack), non-metallic inclusions (such as MnS) can be used as a part of the tool tip and the steel material touching each other. The stress concentration source, and the pores generated by the interface between the non-metallic inclusions and the substrate accelerates crack formation, thereby reducing the force required to operate the cutting. Therefore, in order to improve the cutting property of the quick-cut steel, basically, 1) a large amount of MnS needs to be maintained, 2) MnS must be randomly distributed, and 3) MnS needs to have a large size and is preferably spherical. In fast-cut steel, the shape of MnS varies according to the oxygen content in the continuous casting steel liquid distributor, and can be divided into three forms: spherical (type I); strip (type II φ); and irregular Shape (type III). It is currently known that when MnS is closer to a spherical shape (type I), its cutting property is further improved. If the total oxygen amount (T[0]) in the molten steel distributor reaches several hundred ppm high, MnS will solidify in the molten steel at high temperature and crystallize into a composite sulfide such as Mn (0) in the deoxidation process. , S). At the same time, when the MnS is closer to the strip shape (Type II), if the total oxygen content (τ[ο]) in the molten steel distributor is relatively low, such as tens of ppm, during solidification, in the state of the molten steel. MnS does not crystallize, but it is released along the initial interface of the particles, thus causing MnS to easily extend in the direction of the roll steel during hot rolling of the steel material 5 201006939, resulting in deterioration of material anisotropy. In the solidification process of general steel except for quick-cutting steel, a strip (Type II) structure is produced, and since the strip structure causes significant deterioration of the mechanical properties of the steel, many studies attempt to reduce the content of s to several ppm. Hereinafter, in order to maintain MnS, it will not precipitate during the metallurgical process. Finally, the MnS having an irregular shape (the third type) is characterized in that when the total oxygen amount T [〇] in the molten steel distributor is as low as several ppm and the content of the molten state is high, it is generated at a high temperature. The irregular MnS system is the main one! ^!^ Single inclusions' and it is currently known that irregular MnS is present in the aluminum deoxidized steel in an angular state. In the technology of fast-cutting steel, a polygonal ferrite (such as C, Si, Mn, S, P, Nb, bismuth, etc.) is limited to a specific range and will be used as a fine tissue ( The ratio of the area ratio of p〇iyg〇nai ferrjte) to 5% or more. However, even if a large amount of expensive alloying elements such as Nb, M〇, Zr, etc. are added, this technique cannot clearly specify the effect achieved by the ferroalloy in the fast-cut steel. In addition, although this technique limits the area ratio of polygonal ferrite to a specific range, this technique does not provide an approximate measurement method. In another technique of rapidly cutting steel, a specific amount of C, Si, Μη, S, Ο, Bi, etc. is added, and the content of Bi inclusions per unit square mm in a section of a wire roll steel direction, And the Bi content ratio is limited to a specific value. However, although this technique limits the amount of Bi inclusions and the ratio of Bi content, the ratio is hard to control when actually making steel. In addition, this technology special 201006939 is to add 0.005 wt% or less of oxygen, but such oxygen content is difficult to obtain a high-cutting high-speed steel with good cutting property to control the MnS has a spherical shape, in other words, the first Type I. In still another technique for the production of quick-cut steel, it relates to a sulfur-containing continuous casting quick-cutting steel having the same degree of cutting property as that of the fast-cut steel obtained by the conventional casting method. The sulfur-containing continuous casting quick-cutting steel is characterized in that it contains specific contents of carbon (C), manganese (Mn), phosphorus (P), sulfur (S), nitrogen (N), and oxygen (02), and MnS. The average size of the inclusions is 50/zm2 or less. However, this technique reveals the MnS content, but rarely mentions the particle size and does not provide an indication of the effect of the MnS profile on the cutting properties. Another technique for quick-cutting steel is characterized in that carbon (C), manganese (Mn), phosphorus (P), sulfur (S), nitrogen (N), and oxygen (0) are used as basic components. The content of Si is limited to 0.1 wt% or less, the content of Α1 is limited to 0.009% by weight, the total amount of N is in the range of 20 ppm to 150 ppm, and the oxygen-containing system is 50% or more. However, if the application is considered to be practical, it is difficult to measure the weight of the oxygen-containing inclusions in the fast-cut steel, and this technique is limited to an unmeasurable value in a specific range, so the technique must be effective. And practical issues. In addition to the technology of fast-cutting steel, it is a manufacturing method of Bi-S-based quick-cutting steel, which makes Bi-S-based quick-cutting steel have excellent physical properties and adjusts the size of austenite particles. At a specific size to enhance high temperature ductility. In other words, the Bi-S based fast-cutting steel contains 0.05 wt% to 0.15 wt% of carbon (C), 0.5 wt% to 2.0 wt% of manganese (Mn), and 0.15 wt% to 0.40 wt% of sulfur (S). 0. 01 wt% to 0.10 wt% phosphorus (P), 0.003 wt% to 0.020 7 201006939 wt% oxygen (Ο), 0.03 wt% to 0.30 wt%: (Bi), 0.01 wt% or less Then (Si), 0.0009 wt% or less of aluminum (Al), and an equilibrium component of Fe and unavoidable (ie, unremovable) impurities. The cross-section of the MnS-based inclusions with MnS and adsorbed with lanthanum accounts for 0.5% to 2.0% of the total cross-section of the Bi-S-based quick-cut steel, while the cross-section of the bismuth portion accounts for the total profile of the Bi-S-based quick-cut steel. 0.030% to 0.30%. However, this technique for Bi-S based quick-cutting steel does not provide a related method of how to control the composition of MnS as described in the present invention. SUMMARY OF THE INVENTION The primary object of the present invention is to provide a fast-cutting steel that avoids (or solves) problems associated with the art, or unsolved problems that are apparent in the art, and that is provided by the present invention. Steel cutting meets environmental regulations (rules) and has excellent cutting and thermal properties, and other similar properties. One aspect of the present invention provides a fast-cutting steel comprising: 0.03 wt% to 0.13 wt% of obstacle (C), 0.1 wt% or less of Si Xi (Si), 0.77 wt% to 2.0 wt%猛 (Μη), 0.05 wt% to 0.15 wt% of filling (P), 0. 2 wt% to 0.5 wt% of sulfur (S), 0.001 wt% to 0.01 wt% of shed (B), 0.1 Cwt% to 0.5 wt% chromium (Cr), 0.003 wt% to 0.2 wt% titanium (Ti), 0.005 wt% to 0.015 wt% nitrogen (N), 0.03 wt% or less oxygen (O), and The balance between iron and the inevitable impurities. On the cross section of the direction of the quick-cut steel wire, the steel may have 300 to 1,000 MnS contents having a particle size of 5 μm 2 or more per square mm (mm 2 ). Wherein, the weight ratio between Μη and S can be Mn/S and 3.5. 201006939 Another aspect of the present invention provides a method for fabricating a fast-cutting steel, comprising: introducing an oxygen to a molten metal in a reforming furnace at an ultrasonic wave rate to transform and metallize the molten metal, and Oxygen blowing is stopped when free oxygen is between 400 ppm and 1,000 ppm; the non-deoxygenated oxygen is blown to complete the molten metal into the ladle; from the ladle to the refining furnace (LF) for heating and melting Steel, and then LF metallurgy, until the free oxygen density in the metal melt ranges from 1 〇〇 ppm to 200 ppm; the molten steel is continuously cast using a steel blast so that the time point is equal to the smelting chain Time i 〇〇 /0 ❹ to 50%, the free oxygen density is 50 ppm to 150 ppm; and the steel embryo is maintained in the heating oven of i, 200 ° C to 1,350 ° C for 2 to 5 hours To roll the steel blank to form a wire. Among them, in the continuous casting process, the molten steel can be made into a piece of steel, which can be formed into a steel embryo by rolling the steel blank, and the manufacturing method of the quick-cutting steel can further include: The steel is maintained in a furnace at a temperature of 1,250 eC or above for 4 to 10 hours to roll the steel to form a steel embryo. The quick-cut steel may include: 0.03 wt% to 0.13 wt% of carbon (c), 0.1 ❿ wt% or less of 矽 (si), 0.7 wt. /. To 2.0 wt% (Μη), 0.05 wt% to 0 15 wt% phosphorus (P), 0.2 wt% to 0.5 wt% sulfur (S), 0.001 wt〇/o to 0.01 wt °/. Boron (B), o.1 wt% to o.5 wt% of the complex (Cr), 0,003 wt〇/o to 0.2 wt% of titanium (Ή), 0.005 Wt% to 0,015 Wt% of nitrogen ( N), 0.03 wt% or less of oxygen (〇), and an equilibrium component of iron and unavoidable impurities. On the other side of the direction of the wire roll steel, there may be 300 to 1,000 MnS contents having a particle size of or more per square millimeter (mm2). In particular, the 'continuous casting process can use a magnetic stirrer or a light press device, or at the same time, 9 201006939 is used with the electromagnetic stirrer and the light pressure device, and the weight ratio between Μη and S can be]VIn/S ^; 3.5. In order to achieve the above object, the inventors of the present invention have made a fast-cutting steel which is 1) adding an appropriate amount of Ti, Cr, N, or the like to form a non-metallic content and a precipitate, and 2) controlling Mn/S, The ratio of the other components is 3.5 or more, 3) the total amount of oxygen is limited to 3 〇〇 ppm or less, and 4) the amount of MnS inclusions is adjusted so that the unit is in the cross section of the direction of the steel. The square metric has 300 to 1,000 MnS contents having an area of 5/z m2 or more. The MnS inclusion structure in the fast-cut steel is shown in Fig. i, and at the same time, by limiting the technical characteristics of Ti, Cr, and N, etc., when the solidification is performed, a large amount (e.g., precipitation) can be precipitated at the particle interface. The range is from 0 to 1/zm to 5 from the (Cr, Ti) S group of m or the (Cr, Ti) N group, as shown in Fig. 2. Thereby, it can reach 1) prevent the processing of difficult areas during mechanical operation to improve the cutting property 'and 2) improve the fracture toughness of the steel material to prevent the build-up edge (BUE) and overcome the blade chip generation. To improve the performance of fast cutting steel. Therefore, the use time of the appliance and the surface hardness can be extended. Next, the composition of the fast-cut steel will be described in further detail. Carbon (C) · 〇·〇3 wt% to 0·13 wt% Carbon is an element that forms carbides to increase the strength and hardness of the material. The carbon system is present as a part of pearlite in the fast-cut steel, which is used to prevent the generation of BUE in the appliance when cutting the steel material. If the carbon content is less than 0·03 w%, the hardness of the material cannot be increased to a desired level, and the profit method achieves the effect of limiting the generation of BUE. At the same time, if the carbon (c) content exceeds ^ 201006939 W% ', the hardness of the material will increase greatly, which in turn will shorten the use time of the appliance. Therefore, in one embodiment of the invention, the carbon (c) content is limited to the range of 003 w0 / 〇 to 0.13 W%. Shi Xi (Si): 〇, i wt% or less Shi Xi (Si) is one of the elements in the material because it is present in pig iron or a reducing agent. In addition to the formation of oxides, so-called Si〇2, 矽(si) is mostly s〇lid-s〇luted, so it is known that the crush does not significantly affect the fast cutting. Mechanical properties of steel. However, the inventors of the present invention have found that, in the high-oxygen quick-cutting steel, if the cerium (Si) content exceeds 0·1 w%, Si 〇 2 is generated, which causes the appliance to be used when mechanically cutting the steel quickly. Life expectancy is greatly reduced. Therefore, the present invention does not mainly use bismuth (si). However, if it is considered to be feasible, M (Si) is inevitably present in iron alloys, iron ore, and the like, and thus is implemented in one of the present inventions. In the aspect, the content of Shi Xi (Si) in the fast-cut steel is adjusted to 0.1% or less. Manganese (Μη): 0.7 wt% to 2.0 wt0 / 〇 〇 (Μη) is one of the necessary alloying elements for the formation of non-metallic inclusions MnS, which provides mechanical properties of steel materials. When manganese (Μη) is added in an amount of 〇.7 w % or more' ensures that the MnS inclusions have effective crystallinity and can achieve the effect of reducing the surface defects of the steel during the hot roll process. If the Mn content exceeds 2.0 w%, the hardness of the steel material will decrease and the service life of the appliance will also be shortened. When the content of manganese (Μη) ranges from 0.7 w% to 2.0 w%, some of them will combine with oxygen to form ΜηΟ, which can be used as a nucleus to form nucleus in the solidification process to accelerate the formation of spherical MnS inclusions. Phosphorus (P): 0.05 wt% to 0.15 wt% 201006939 Phosphorus (P) is one of the elements used to inhibit the formation of BUE at the front end of the cutting device. If the phosphorus (P) content is less than 0.05 w%, the effect of inhibiting the formation of BUE is hardly produced. If the phosphorus (P) content exceeds 0.15 w%, the BUE suppression effect is good, but the hardness of the steel material is increased, and the cutting tool is shortened. Service life. Therefore, in one embodiment of the present invention, the content of phosphorus (P) is limited to the range of 0.05 wt% to 0.15 wt%. Sulfur (S): 0.2 wt% to 0.5 wt ° / 硫 In fast-cut steel, sulfur is used to form MnS inclusions during solidification. As described above, MnS is used to improve the mechanical properties of the steel material, thereby reducing the wear of the cutting tool and increasing the surface hardness of the working member. Therefore, MnS is one of the most important components in the present invention. For the above purpose, the amount of sulfur (S) added is 0.2 wt% or more. However, the inventors of the present invention have experimentally shown that if the amount of sulfur (S) added is too large, it causes a network (like a net) FeS to precipitate on the particle interface. FeS is very fragile and has a low melting point, which tends to cause a significant deterioration in the characteristics of the heat roller. At the same time, if the sulfur content exceeds its requirements, it will lead to an increase in surface defects of the steel material, and at the same time, the hardness and ductility of the steel material are significantly deteriorated. Therefore, the sulfur (S) content must not exceed 0.5 wt ° / 〇. Boron (B): 0.001 wt% to 0.01 wt% Butterfly (B) is used to increase the quenching characteristics of steel materials. Therefore, in the present invention, a butterfly (B) of 10 ppm to 100 ppm is added. If the amount of the shed (B) is not less than 10 ppm, it may be difficult to appropriately improve the quenching characteristics. However, if the boron (B) is added in an amount exceeding 100 ppm, the quenching characteristics may be sufficiently improved, but the high temperature ductility may be deteriorated and the refractory property may not be performed. Hot roll process. Therefore, the boron (B) content should have the above limitations. 201006939 Complex (Cr): 〇·1 wt% to 0.5 wt0/〇 Chromium (Cr) is one of the elements that can expand the Austrian body region. In other words, chromium is an essential component and is a cheap general alloying element. Even if the chromium content is large, the carbide formed by chromium does not cause material extraction. The addition of Cr forms a (Cr,Mn)s-based non-metallic inclusion having a larger particle size. Further, the addition of Cr prevents deformation of the non-metallic inclusions, and the inclusions can be uniformly distributed in the material during the rolling step. In the embodiment of the present invention, the addition of chromium enhances the mechanical properties, and the inventors of the present invention have experimentally confirmed that when the amount of chromium added is less than 0.1%, the effect of improving mechanical properties cannot be produced'. More than 0.5 wt% 'mechanical properties reach an upper limit and will not continue to increase. Therefore, the content of chromium (Cr) is limited to the range of wt3 wt% to 0.5 wt%. Preferably, the amount of chromium (Cr) added may be from 1 wt% to 0.5 wt%. Chin (Ti) · 0.003 wt% to 〇·2 wt% Titanium (Ti) and any of oxygen (Ο), nitrogen (N), carbon (c), sulfur (s), hydrogen (Η), and similar elements The elements exhibit excellent affinity, especially when titanium is used in the deoxygenation, denitrification, desulfurization, and similar reactions. In addition, Qin (Ti) is prone to breakage and smelting of particles. The related verification of the present invention actually adds more than 0.003 wt% of titanium (Ti), and the smelting of the particles can greatly improve the mechanical properties. In addition, the addition of Ti enhances the hardenability to prevent the formation of BUE, thereby improving mechanical properties. However, if the titanium (Ή) content exceeds 0.2 wt ° / 〇, the effect of improving the mechanical properties has reached the upper limit, but the life of the cutting device is shortened due to the formation of Ti 〇 2 in the material. Therefore, the titanium (Ti) content should be limited to 13 201006939 in the range of 0.003 wt% to 0.2 wt%, preferably 0.008 wt% to 0.15 wt% 0 H(N): 0.005 wt% to 0.015 wt% nitrogen is a kind One of the elements that affect the BUE generation and the surface roughness of the cutting object in the cutting tool. If the nitrogen (N) content is less than 0.005 wt%, the BUE generation is increased and the surface roughness is deteriorated. When the nitrogen content is increased, the BUE production is reduced, but when the nitrogen (N) content exceeds 0.015 wt%, the surface defect of the steel-cut steel which is die-casting is increased, which has another disadvantage. Therefore, in the present invention, the nitrogen (N) content is limited to the range of 0.005 to 1% to 0.015 to 1 ° / Torr. Oxygen (0): 0.03 wt% or less Oxygen (Ο) is used to form fine MnO in the initial step of solidifying molten steel in the mold during die casting, and MnO is used as MnS. The crystal nucleation point of crystallization. Here, the oxygen referred to is the total amount of oxygen (T. [0]) present in the die-cast steel (i.e., cast plate). As described above, when the oxygen content is several tens ppm or less, when the molten steel solidifies, the MnS in the second type or the third type may precipitate, and the type of MnS causes the cutting property of the quick-cut steel. (ie mechanical properties) deterioration. In the present invention, in order to have optimum cutting properties, the main object is to produce a first type of MnS crystal, so-called spherical MnS. The experimental results show that when the oxygen content is increased, the spherical MnS can be effectively crystallized, but if the oxygen content exceeds 0.03 wt%, the surface defects such as needle sticks, pores, or similar pores are greatly increased. Therefore, the upper limit of the oxygen content must be limited. Weight ratio of manganese (Μη) to sulfur (S): Mn/S23.5 201006939 In addition to adjusting the content of the component, in order to make the fast-cutting steel have better ductility at high temperatures, it is necessary to control manganese (Mn) and sulfur (S). The ratio is such that the Mn/S ratio is 3.5 or more by weight. This ratio is to prevent the FeS hot brittleness caused by the mixing of Μ ()η) and sulfur (S), and it is necessary to ensure that the Μη content is above a certain value. In particular, if the ratio of manganese (Mn) and sulfur (S) is less than 3.5, the characteristics of the hot roll are deteriorated, and it is difficult to obtain the fast-cut steel to be obtained by the present invention. Further, in the section of the direction of a wire roll steel, there are 300 to 1,000 MnS having a particle size of 5 #m2 or more per square inch (mm2). Φ The cutting property (ie mechanical properties) of the fast-cut steel varies with the size and distribution of the non-metallic inclusions in the steel. In general, when the MnS particles are large and the MnS content is large, the steel material has better cutting properties. According to the optical microscope measurement and the cutting property test evaluation result of the inventors of the present invention, when in the direction of a wire roll steel (ie, the L direction), there are 300 to 1,000 particle sizes per square mm (mm2) exceeding 5/z. When the MnS of m2 is used, the cutting property of the steel material is optimal. When there are less than 300 MnS, the use of the appliance is shortened due to poor cutting property, and the surface roughness of the processing region is deteriorated. At the same time, if the number of MnS exceeds 1,000, the service life of the appliance can be increased, but the workability of the steel is deteriorated (poor). Therefore, the amount of MnS is preferably controlled within the range of 300 to 1,000. Next, referring to Fig. 3, a method of fabricating a quick-cut steel comprising the above alloy composition will be described in detail, which is applicable to the present invention. Conversion and metallurgical chain: First, the oxygen is introduced into the metal melt in the reformer at a supersonic rate to remove the air or slag contained in the metal melt. C, 15 201006939
Si、Μη、P等不純物。於轉化冶鍊製程中，當包含在金屬熔 融物中之游離氧轉化範圍為400 ppm至1,000 ppm時，停止 氧氣吹煉。若氧少於400 ppm，金屬炼融物申之碳含量會超 過本發明組成範圍，導致碳成分控制不易。同時，若氧超 過1,000 ppm，則會導致如轉化爐、盛鋼桶、即相似裝置等 耐火器具過度腐蝕。 排放非去氧狀態之鋼材： 將氧氣吹煉完成金屬熔融物以非去氧狀態接至（排放 至）盛鋼桶中，在此，若需要，可在排放操作過程中添加如 鐵合金或相似產物等副材料。適當範圍之鐵合金或副材料 添加，可形成溶融態鋼材或爐漬。 精煉爐（LF)加熱： 當排放結束後，將盛鋼桶轉移至LF中，以加熱熔融鋼 材。至於金屬熔融物之加熱過程，係透過形成在LF中之碳 電極棒通入電弧以提升、熔融鋼材溫度。於加熱過程中，若 需要可添加鐵合金或其他副材料，或者是依照使用條件， 可取出熔融鋼材測試樣品，或是可測量熔融鋼材氧密度。 當加熱熔融鋼材時，於爐渣中之氧化合物或是空氣中的 氧，可透過電弧分解並通入金属溶融物中，以增加炫融鋼 材之氧密度。於LF中，LF精煉操作終止時間，較佳為當熔 融金屬中游離氧密度在100 ppm至200 ppm範圍内。若在當 游離氧密度低於100 ppm時停止LF精煉操作，則可能難以形 成所欲之MnS，反之，若在當游離氧密度超過200 ppm時停 止LF精煉操作，於接下來步驟可能難以預測熔融態金屬組 201006939 成物變化，而難以控制熔融態金屬之組成。因此，透過游 離氧密度控制停止LF精煉操作之時間點，應控制在1〇〇 ppm 至200 ppm範圍内。 吹煉連鑄： 經加熱而完成LF精煉操作之熔融鋼材，係轉移至一連 鑄裝置中’並進行熔融鋼材之連鑄。於開始進行連鑄時， 先測量熔融鋼材中之游離氧密度，以事先確保鑄造之快削 鋼是否具有良好之切割性。當經過總鑄鋼時間之10%至50% β 時，測量游離氧密度’在此，游離氧密度需在5〇 ppm至150 ppm之間。若在鑄鋼時間之1〇%之前測量游離氧密度，因鋼 液分配器耐火物質、鋼液分配器保溫物質、或相似物等影 響’而難以得到準確之游離氧密度，反之，若在鑄鋼時間 之50%之後測量游離氧密度，則可能會錯失控制氧密度之時 機。此外，經由實驗顯示，當所測得之游離氧密度低於50 ppm時’切割性較差，而當所測得之游離氧密度超過15〇 pprn 時’則多少會造成所鑄造之鋼件（即鋼胚）中有針孔或氣孔增 〇 加。於快削鋼模鑄過程中，較佳鑄鋼鋼件可使用一模具電 磁攪拌器（mold EMS)或輕壓裝置所製得。使用模具EMS有 助於製得粒徑較大之球狀MnS内含物，而使用輕壓裝置則 更加有助於減少鋼胚中心偏析（center segregation)以及鋼胚 表面之表面缺陷，如針孔或吹孔。於快削鋼之連鑄製程中， 連鑄製程基本上可使用300mm X 400mm、400mm X 500mm 專尺寸之塊鋼，或是120mm x 120mm、160mm x 160mm等 尺寸之鋼胚。於此實施態樣中，若於連鑄製程中使用塊鋼， 17 201006939 則可採用鋼胚棍乳製程，即所謂之製作快削鋼鋼胚製程. 然而，若於輥軋製程中使用鋼胚’則可省略鋼胚輕軋製程 而可進行線材輥軋製程。 塊鋼輥軋成鋼胚： 於連鑄製程中，若進行塊鋼模鑄，而非進行鋼胚模鑄， 則需額外進行將塊鋼輥軋成鋼胚之製程。當使用3〇〇mm χ 400mm或400mm x 500mm之快鋼輥軋成 120mm x l2〇mm^ 160mm x 160mm之鋼胚時，一般稱之為鋼胚輥軋或鋼胚 化，同時，於鋼胚輥軋製程中最重要的是為鋼材溫度以及 加熱爐持續加熱時間《若鋼材在低溫下輥軋，則所製得之 鋼胚表面將會嚴重損毀。因此，於本發明一實施態樣中， 加熱爐溫度係限制在1，250°C或以上，並維持四至十小時。 經實驗證實，當鋼材溫度低於125〇t3C，若鋼胚在加熱爐中 時間過長，則會造成所製得之鋼胚表面性質劣化；然而， 即使塊鋼溫度維持在或以i ,若加熱爐所維持之加 熱時間少於四小時’則鋼胚表面性質亦會劣化。同時，當 塊鋼維持在加熱爐中超過十小時，且塊鋼溫度維持^ 1’250〇C或以上，則會造成產率大幅降低，但若是四至十小 時，則可得到具有相同表面性質之鋼胚。因此，加熱爐所 維持之加熱時間必須限制在四至十小時。 輕軋線材： ▲當快削鋼以-鋼胚模鑄時，或是當快削鋼係以— 模鱗而後再進行塊鋼之鋼純鑄以形成鋼胚時，將鋼胚 仃輥軋製程以形成一線材。從快削鋼鋼胚製作線材之製程 201006939 中，最重要的影響因素為加熱爐溫度以及持續加熱時間。 為了得到具良好表面性質之快削鋼，鋼胚溫度較：係二 在1 ’200。。至1，35(PC的加熱爐中二至五小時。當鋼胚溫度低 於1，200〇C’則不易得到良好線材表面性質，❿當鋼胚溫度 超過1，350。<：，則不易得到相對較佳之線材表面性質。同 時，若於加熱爐中的持續加熱時間少於兩小時，則不易得 到良好線材表面性質，而相較於維持加熱時間二至五小 時，即使在加熱爐中維持加熱時間超過五小時，仍難以取 ® 得具有較佳線材表面性質。 【實施方式】 接下來將透過下述實施例更加詳細描述本發明。 [實施例1]Impurities such as Si, Μη, P, etc. In the conversion and smelting process, when the free oxygen conversion range contained in the metal melt is from 400 ppm to 1,000 ppm, the oxygen blowing is stopped. If the oxygen is less than 400 ppm, the carbon content of the metal smelt will exceed the composition range of the present invention, resulting in difficulty in controlling the carbon component. At the same time, if the oxygen exceeds 1,000 ppm, it will cause excessive corrosion of refractory appliances such as reformers, ladle, or similar devices. Discharge of non-deoxidized steel: Oxygen blowing completes the metal melt to be non-deoxygenated (discharged) into the ladle, where if necessary, such as ferroalloy or similar products may be added during the discharge operation And other auxiliary materials. A suitable range of ferroalloys or by-materials can be added to form molten steel or furnace stains. Refining Furnace (LF) Heating: When the discharge is complete, transfer the ladle to LF to heat the molten steel. As for the heating process of the molten metal, the arc is passed through the carbon electrode rod formed in the LF to raise and melt the temperature of the steel. During the heating process, if necessary, iron alloy or other auxiliary materials may be added, or the molten steel test sample may be taken out according to the use conditions, or the oxygen density of the molten steel may be measured. When the molten steel is heated, the oxygen compound in the slag or the oxygen in the air can be decomposed by the arc and passed into the metal melt to increase the oxygen density of the molten steel. In LF, the LF refining operation is terminated, preferably when the free oxygen density in the molten metal is in the range of 100 ppm to 200 ppm. If the LF refining operation is stopped when the free oxygen density is less than 100 ppm, it may be difficult to form the desired MnS. Conversely, if the LF refining operation is stopped when the free oxygen density exceeds 200 ppm, it may be difficult to predict melting in the next step. The metal group 201006939 changes in composition, and it is difficult to control the composition of the molten metal. Therefore, the point in time at which the LF refining operation is stopped by the free oxygen density control should be controlled in the range of 1 〇〇 ppm to 200 ppm. Blowing and continuous casting: The molten steel which is heated to complete the LF refining operation is transferred to a continuous casting apparatus' and continuous casting of molten steel. At the beginning of continuous casting, the density of free oxygen in the molten steel is measured to ensure in advance whether the cast fast-cut steel has good cutting properties. When the total casting time is 10% to 50% β, the free oxygen density is measured. Here, the free oxygen density needs to be between 5 〇 ppm and 150 ppm. If the free oxygen density is measured before 1% of the casting time, it is difficult to obtain an accurate free oxygen density due to the influence of the steel liquid distributor refractory material, the steel liquid distributor insulation material, or the like, and vice versa. Measuring the free oxygen density after 50% of the steel time may miss the opportunity to control the oxygen density. In addition, experiments have shown that when the measured free oxygen density is less than 50 ppm, the 'cutting property is poor, and when the measured free oxygen density exceeds 15 pp pprn', it will cause the cast steel piece (ie There are pinholes or pores in the steel embryo. In the fast-cutting steel die casting process, the preferred cast steel parts can be produced using a mold electromagnetic stirrer (mold EMS) or a light press device. The use of the mold EMS helps to produce spherical MnS inclusions with larger particle sizes, while the use of a light pressure device is more conducive to reducing center segregation and surface defects of the steel surface, such as pinholes. Or blow holes. In the continuous casting process of the quick-cutting steel, the continuous casting process can basically use 300mm X 400mm, 400mm X 500mm special-sized block steel, or steel embryos of 120mm x 120mm, 160mm x 160mm size. In this embodiment, if a block steel is used in the continuous casting process, 17 201006939 may use a steel preform process, which is a so-called process for making a quick-cut steel blank. However, if a steel blank is used in the roll rolling process 'The steel rolling process can be omitted and the wire rolling process can be carried out. Rolling of bar steel into steel preform: In the continuous casting process, if the block steel is cast instead of the steel die casting, an additional process of rolling the block steel into a steel blank is required. When using a 3〇〇mm χ 400mm or 400mm x 500mm fast steel roll to roll into a 120mm x l2〇mm^160mm x 160mm steel blank, it is generally called steel blank rolling or steel embryo, and at the same time, in the steel embryo The most important part of the rolling process is the temperature of the steel and the continuous heating time of the furnace. If the steel is rolled at a low temperature, the surface of the steel blank produced will be seriously damaged. Therefore, in one embodiment of the invention, the furnace temperature is limited to 1,250 ° C or above and maintained for four to ten hours. It has been experimentally confirmed that when the steel temperature is lower than 125〇t3C, if the steel embryo is too long in the heating furnace, the surface properties of the obtained steel embryo will be deteriorated; however, even if the temperature of the steel is maintained at or i, If the heating time maintained by the furnace is less than four hours, the surface properties of the steel blank will also deteriorate. At the same time, when the block steel is maintained in the heating furnace for more than ten hours, and the temperature of the block steel is maintained at 1 '250 ° C or above, the yield is greatly reduced, but if it is four to ten hours, the same surface properties can be obtained. Steel embryo. Therefore, the heating time maintained by the furnace must be limited to four to ten hours. Light-rolled wire: ▲When the quick-cutting steel is cast by -steel die casting, or when the quick-cutting steel is used as the die scale and then the steel of the block steel is purely cast to form the steel blank, the steel blank rolling process is started. To form a wire. From the process of making wire for quick-cutting steel blanks 201006939, the most important factors are the furnace temperature and the continuous heating time. In order to obtain a fast-cut steel with good surface properties, the temperature of the steel embryo is 2:200. . To 1,35 (two to five hours in the heating furnace of PC. When the temperature of the steel is less than 1,200 〇C', it is not easy to get good surface properties of the wire, and the temperature of the steel is more than 1,350. <: It is not easy to obtain a relatively good surface property of the wire. Meanwhile, if the continuous heating time in the heating furnace is less than two hours, it is difficult to obtain a good wire surface property, compared to maintaining the heating time for two to five hours, even in a heating furnace. It is still difficult to obtain a preferred wire surface property while maintaining the heating time for more than five hours. [Embodiment] Next, the present invention will be described in more detail by way of the following examples. [Example 1]
於本實施例中，如下表1所列之實施例與比較例鋼材組 成物’係使用200kg高頻空氣感應熔煉爐製作。在此，比較 例係為最被廣泛使用之無鉛快削鋼，而實施例與比較例均 〇 透過相同實驗設備及製作方法製造，且尺寸為230mm X 230mm X 350mm。 [表1] C Si Μη Ρ S N(ppm) 其他成分 實驗例1 0.09 0.01 1.0 0.08 0.25 98 Cr 0.4 ' Ti 0.2 實驗例2 0.08 0.02 1.1 0.08 0.30 78 Cr 0.1 ' Ti 0.02 實驗例3 0.08 0.03 1.2 0.08 0.30 83 Cr 0.3、Ti 0.006 實驗例4 0.071 0.02 1.3 0.09 0.32 65 Cr 0.5、Ti 0.06 實驗例5 0.08 0.03 1.2 0.08 0.30 83 Cr 0.2、Ti 0.005 比較例1 0.08 0.03 1.2 0.08 0.33 85 Pb 0.25 201006939 將鋼材於1，300°C加熱爐中加熱，而後使用試軋機輥軋 成厚度為3 0 mm之金屬板。接著，將金屬板切割成尺寸為 30mm X 30mm方形，再於摘板（即齒轨）上加工以形成直徑為 25 mm之環桿（條狀物）。而後，在CNC搁板上對直徑為25 mm 之環桿進行切割性評估試驗，以測量器具使用時間特性及 切割面表面粗糙度。切割性評估試驗之進行條件，係為切 割速率為100 m/min、切割深度為1.0 mm、而轉速為0.1 mm/rev，且係在未使用潤滑油並維持乾燥狀態下進行。 器具使用壽命特性之實驗，係測量與切割時間相關之 側面磨耗（一般常用於檢測中），而表面粗糙度之實驗，係採 用與切割時間相關之表面粗糙度。側面磨耗與表面粗糙度 之單位分別為（m)，且當數值越小表示表面特性提升。圖4 係為本發明實施例與比較例之器具使用時間實驗例之結果 圖。值得注意的是，本發明實驗例與比較例具有相同器具 使用壽命長度。同時，於圖5中，可發現在相同時間區間中， 本發明之實驗例與習知無鉛快削鋼具有相同程度之表面特 性，甚至較佳於習知無鉛快削鋼。 由實驗可確定的是，含有預定含量之Cr、Ti、及N以取 代Pb之快削鋼，其表面粗糙度及器具使用時間均與無鉛快 削鋼（對人體有害）相同甚至效果更佳之原因係為，若具有 0.2 wt%至0.5 wt%之硫的高含氧快削鋼中含有0.1 wt%至0.5 wt0/〇之鉻、0.003 wt%至 0.2 wt%之鈦、以及 0.005 wt%至 0.015 wt%之氮，則當熔融態鋼材凝固時，於顆粒介面會沉澱出大 量粗糙且尺寸為1 /z m之（Cr，Mn)S基、（Cr, Ti)S基、以及（Cr, 201006939In the present embodiment, the examples listed in the following Table 1 and the steel composition of the comparative example were produced using a 200 kg high-frequency air induction melting furnace. Here, the comparative example is the most widely used lead-free quick-cut steel, and the examples and comparative examples are both manufactured by the same experimental equipment and manufacturing method, and have a size of 230 mm X 230 mm X 350 mm. [Table 1] C Si Μη Ρ SN (ppm) Other components Experimental Example 1 0.09 0.01 1.0 0.08 0.25 98 Cr 0.4 ' Ti 0.2 Experimental Example 2 0.08 0.02 1.1 0.08 0.30 78 Cr 0.1 ' Ti 0.02 Experimental Example 3 0.08 0.03 1.2 0.08 0.30 83 Cr 0.3, Ti 0.006 Experimental Example 4 0.071 0.02 1.3 0.09 0.32 65 Cr 0.5, Ti 0.06 Experimental Example 5 0.08 0.03 1.2 0.08 0.30 83 Cr 0.2, Ti 0.005 Comparative Example 1 0.08 0.03 1.2 0.08 0.33 85 Pb 0.25 201006939 Steel in 1 It was heated in a 300 ° C heating furnace and then rolled into a metal plate having a thickness of 30 mm using a trial rolling mill. Next, the metal plate was cut into a size of 30 mm X 30 mm square, and then processed on a picking plate (i.e., a rack) to form a ring bar (strip) having a diameter of 25 mm. Then, a 25 mm diameter ring bar was subjected to a cutting evaluation test on a CNC shelf to measure the time characteristics of the appliance and the surface roughness of the cut surface. The cutting evaluation test was carried out under the conditions of a cutting rate of 100 m/min, a cutting depth of 1.0 mm, and a rotational speed of 0.1 mm/rev, and was carried out without using lubricating oil and maintaining a dry state. The test of the service life characteristics of the appliance is to measure the side wear associated with the cutting time (usually used for testing), while the surface roughness test uses the surface roughness associated with the cutting time. The units of side wear and surface roughness are (m), respectively, and the smaller the value, the higher the surface characteristics. Fig. 4 is a view showing the results of an experimental example of the use time of the apparatus of the embodiment and the comparative example of the present invention. It is to be noted that the experimental examples of the present invention have the same length of service life as the comparative examples. Meanwhile, in Fig. 5, it can be found that the experimental examples of the present invention have the same degree of surface characteristics as the conventional lead-free quick-cut steel in the same time interval, and are even better than the conventional lead-free quick-cut steel. It can be determined from experiments that the surface roughness and the service life of the fast-cut steel containing a predetermined content of Cr, Ti, and N instead of Pb are the same as or better than the lead-free fast-cut steel (harmful to the human body). For example, if the oxygen-containing fast-cut steel having 0.2 wt% to 0.5 wt% of sulfur contains 0.1 wt% to 0.5 wt% of chromium, 0.003 wt% to 0.2 wt% of titanium, and 0.005 wt% to 0.015. When the molten steel is solidified, a large amount of coarse (Cr, Mn) S-based, (Cr, Ti) S-based, and (Cr, 201006939) precipitated on the particle interface.
Ti)N基細小沉澱物，而這樣的沉澱物可達到防止鋼材材料 在部件機械操作過程中操作不易、並達到可降低降低鋼材 材料破裂特性與其他相似目的，因此，可限制BUE生成並 改善碎片現象。 [實施例2] 將尺寸為300mm X 400mm之連鑄完成快削鋼塊鋼，透 過鋼胚親軋製程親製成尺寸為160mm X 160mm之鋼胚，接 著，將鋼胚透過線材親軋製程耗製成直徑為25 mm之線材。 φ 於一般快削鋼輥軋條件下，將鋼材及鋼胚加熱及冷卻。從 輥軋完成之線材中取出測試樣品，並利用N/O分析儀測量總 氧量，且透過光學顯微鏡觀察MnS面積及外形。同時，將 線材輥軋完成之線材進行冷軋拉伸製程，以製得環桿（即冷 拉（CD)條狀物），並在相同條件下使用CNC搁板進行切割性 測試，以測量器具之使用時間特性。下表2係顯示經由實驗 所得之線材總氧量（ppm)、每單位平方公厘（mm2)中面積為 5(m2或以上之MnS數量、以及使用時間。於表2中，器具使 ^ 用時間係表示可使用單一切割器具切割之部件相對數目。 [表2] 類別 總氧量 (T.[0])，ppm 每單位面積之 MnS數量 (5 // m2或以上） 器具使用時間 (次數） 實驗例6 133 316 5,3〇〇 實驗例7 138 627 5,500 實驗例8 290 525 6,500 實驗例9 235 467 6,200 比較例2 116 288 4,400 比較例3 220 219 3,100 21 201006939 比較例4 315 527 5,800 比較例5 380 427 5,700 於表2中，當線材總含氧量在3 00 ppm範園内且每單位 面積MnS數目在300至1，000範圍内（實驗例6至9)時，器具使 用壽命為5,000次以上，或是較使用者所使用之快削鋼部件 所需標準要高。同時，即便總氧量仍在本發明所述之範圍 内，如比較例2及3，當每單位面積MnS數目少於300時，器 具使用壽命則無法超過使用者使用快削鋼部件所需標準之Ti) N-based fine precipitates, and such precipitates can prevent the steel material from being difficult to operate during the mechanical operation of the parts, and can achieve the purpose of reducing the fracture characteristics of the steel material and other similar purposes, thereby limiting BUE generation and improving debris. phenomenon. [Example 2] A steel piece having a size of 300 mm X 400 mm was continuously cast, and a steel piece having a size of 160 mm X 160 mm was formed by a steel blasting process, and then the steel piece was passed through the wire. Made of wire with a diameter of 25 mm. φ Heat and cool steel and steel blanks under normal fast-rolling steel rolling conditions. The test sample was taken out from the rolled wire, and the total oxygen amount was measured by an N/O analyzer, and the area and shape of the MnS were observed through an optical microscope. At the same time, the wire rolled by the wire is subjected to a cold rolling drawing process to obtain a ring rod (ie, a cold drawn (CD) strip), and the cutting test is performed using a CNC shelf under the same conditions to measure the instrument. Use time characteristics. Table 2 below shows the total oxygen content (ppm) of the wire obtained by the experiment, the area per unit square millimeter (mm2) is 5 (the number of MnS of m2 or more, and the use time. In Table 2, the appliance is used Time is the relative number of parts that can be cut with a single cutting instrument. [Table 2] Total Oxygen Content (T.[0]), ppm MnS per unit area (5 // m2 or more) Appliance usage time (number of times) Experimental Example 6 133 316 5, 3 〇〇 Experimental Example 7 138 627 5,500 Experimental Example 8 290 525 6,500 Experimental Example 9 235 467 6,200 Comparative Example 2 116 288 4,400 Comparative Example 3 220 219 3,100 21 201006939 Comparative Example 4 315 527 5,800 Comparison Example 5 380 427 5,700 In Table 2, when the total oxygen content of the wire is within 300 ppm and the number of MnS per unit area is in the range of 300 to 1,000 (Experimental Examples 6 to 9), the service life of the appliance is 5,000. More than or equal to, or higher than the standard required for the faster-cut steel parts used by the user. Meanwhile, even if the total oxygen amount is still within the range described in the present invention, as in Comparative Examples 2 and 3, the number of MnS per unit area When the number is less than 300, the service life of the appliance cannot exceed the user. Standards required by cutting steel member
5,000次。造成此現象之原因在於，具有相對較大面積之MnS 較少’而導致碎裂產生，進而造成應用範圍相對較少。同 時，於比較例4及5中，每單位面積中之MnS數目係在本發 明之範圍内，且切割器具之使用壽命亦超過參考值5 〇〇〇 次，但是，由缚鋼件（即鑄鋼鋼板、或塊鋼）回復至條狀 物之回收率卻低於80%。值得注意的是，造成此現象之因 素，係為總氧量過高，超過300 ppm，其為導致鑄鋼件表面 有針孔及吹孔之主要因素，因而無法改善鋼胚製程以及線5,000 times. The reason for this is that the relatively large area of MnS is less, resulting in fragmentation, resulting in a relatively small range of applications. Meanwhile, in Comparative Examples 4 and 5, the number of MnS per unit area is within the scope of the present invention, and the service life of the cutting tool also exceeds the reference value of 5 times, but by the steel fitting (ie, casting) The recovery rate of the steel sheet or block steel to the strip is less than 80%. It is worth noting that the cause of this phenomenon is that the total oxygen content is too high, exceeding 300 ppm, which is the main factor causing pinholes and blowholes on the surface of the steel castings, thus failing to improve the steel blank process and the line.
材輥軋製程。因此，總氧量過高會導致大量的表面缺陷、 較低之回收率、以及成本增加，進而難以達到本發明之目 的0 不赞明之貫驗例，用装綱製程； 鑄製程輕易製作出無硫㈣鋼，且由於製㈣程中有| 球狀MnS結晶，藉此，可提供切祕（即機械特，旬大^ 且具有較佳熱加工性(即熱輥特性)之環保快削鋼。田 22 201006939 本發明僅以較佳實施例加以描述，然而本技術領域者 可在不偏離本發明所主張之權利範圍下，進行修飾與修改。 上述實施例僅係為了方便說明而舉例而已，本發明所 主張之權利範圍自應以申請專利範圍所述為準，而非僅限 於上述實施例。 【圖式簡單說明】 • 本發明之上述及其他態樣、特徵以及其他優點，可伴 隨圖式以及詳細描述更加了解，其中： 圖1係MnS包含物外型之顯微鏡照片。 圖2係高含氧快削鋼中Cr、Ti、n、及S基沉澱物與MnS包 含物共存之顯微鏡照片。 圖3係本發明一實驗例之環保無鉛快削鋼製作流程示意圖。 圖4係為一滿足本發明實施例條件之實驗例與比較例之写 具使用壽命比較圖。 圖5係為一滿足本發明實施例條件之實驗例與比較例之表 ® 面粗糙度比較圖。 【主要元件符號說明】 無。 23Roll rolling process. Therefore, too high total oxygen amount leads to a large number of surface defects, low recovery rate, and increased cost, which makes it difficult to achieve the object of the present invention. 0 Unconventional inspection example, using the assembly process; Sulfur (four) steel, and because of the spherical (Mn) crystals in the (four) process, it can provide the cutting-edge (ie, mechanical, special, and hot-rolling properties) The present invention is described by way of a preferred embodiment, and modifications and alterations may be made by those skilled in the art without departing from the scope of the invention. The scope of the claims is intended to be limited by the scope of the invention, and not limited to the above embodiments. [Simplified Description of the Drawings] The above and other aspects, features and other advantages of the present invention may be accompanied by the drawings. The formula and detailed description are better understood, among which: Figure 1 is a micrograph of the shape of the inclusion of MnS. Figure 2 shows the coexistence of Cr, Ti, n, and S-based precipitates in the high oxygen-containing fast-cut steel with MnS inclusions. Fig. 3 is a schematic view showing the manufacturing process of the environmentally friendly lead-free quick-cut steel according to an experimental example of the present invention. Fig. 4 is a comparison diagram of the service life of the writing examples of the experimental example and the comparative example satisfying the conditions of the embodiment of the present invention. A comparison table of the surface roughness of the experimental example and the comparative example satisfying the conditions of the examples of the present invention. [Explanation of main component symbols] None.