JPS6230852A - Extra-soft ferritic stainless steel - Google Patents
Extra-soft ferritic stainless steelInfo
- Publication number
- JPS6230852A JPS6230852A JP61033480A JP3348086A JPS6230852A JP S6230852 A JPS6230852 A JP S6230852A JP 61033480 A JP61033480 A JP 61033480A JP 3348086 A JP3348086 A JP 3348086A JP S6230852 A JPS6230852 A JP S6230852A
- Authority
- JP
- Japan
- Prior art keywords
- less
- stainless steel
- hardness
- ferritic stainless
- coins
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は極軟質フェライ)・系ステンレスinに係リ、
特に貨幣、メダル、ゲーム用コインもしくは鍵等の如く
冷間プレスにより精密な圧印加工が必要とされる各種製
品の素材として最適な極軟質フェライト系ステンレス鋼
に関する。[Detailed description of the invention] [Industrial field of application] The present invention relates to ultra-soft ferrite-based stainless steel.
In particular, the present invention relates to ultra-soft ferritic stainless steel that is ideal as a material for various products that require precise coining by cold pressing, such as coins, medals, game coins, keys, etc.
雑誌rchromium ReviewJ No、 1
1983年4月号によれば1979年に全世界の11
7ケ国で新たに発行されたコイン総量の55%以上はス
テンレス鋼が使用されているという。これはコイン製造
上の経済性およびコインの流通に際しての耐久性の観点
からステンレス鋼が見方されていることを意味している
。Magazine rchromium ReviewJ No. 1
According to the April 1983 issue, in 1979 the world's 11
More than 55% of all new coins issued in seven countries are made of stainless steel. This means that stainless steel is being looked at from the viewpoint of economy in coin production and durability in coin circulation.
ステンレス鋼コインは魅力的な光沢を有し、耐食性、耐
摩耗性がすぐれており、経済的な観点からも銅合金等の
他の材料と比較して有利性を持っているが、このコイン
への適用に当って最大の問題点は、その硬さが硬いこと
にあり、そのためコイニング(圧印)時に大容量のプレ
ス能力が必要とされること、コイニング時のダイスの寿
命が短いこと等コイン製造上の種々の困難を伴うという
問題である。Stainless steel coins have an attractive luster, excellent corrosion and abrasion resistance, and are economically advantageous compared to other materials such as copper alloys. The biggest problem with its application is that it is hard, so a large press capacity is required during coining (coining), and the life of the die during coining is short. This problem involves the various difficulties mentioned above.
第1表最下段から3段目に最も古くからステンレス鋼を
素材とずろコインの製造を行っているイタリアの100
リラコインの組成分析値と、該コインに750℃5分間
の焼鈍を施し再結晶状態で測定した硬さHvを示した。Table 1: 3rd row from the bottom shows 100 Italian coins that have been manufacturing stainless steel coins for the longest time.
The compositional analysis values of the Lila coin and the hardness Hv measured in the recrystallized state after annealing the coin at 750° C. for 5 minutes are shown.
第1図は該コインの圧印状況を示す表面形状であり、第
2図は75%Cu−25%Niを含む日本の100円白
8貨幣の圧印状況を示す表面形状である。第1表より明
らかなとおり、現用イタリアのコイン用ステンレス鋼は
焼なまし状態で硬さが約Hv 163と硬質てあり、第
1図、第2図の比較からも明らかな如く、イタリアのス
テンレス鋼を素材とするコインは日本の白銅を素材とす
る100円貨幣よりも表面の模様の彫りが浅く不鮮明で
ある。コインの彫りの深さは圧印用プレスの圧力を高め
ることによって改善されるが、一方高価なダイスの寿命
を短縮する結果となり経済的に得策ではない。かくの如
く、コイン用素材としてステンレス鋼の種々の利点を十
分に生かすために、先ずその硬質性を改善することが極
めて重要であることが理解されろ。FIG. 1 shows the surface shape of the coin showing the coining condition, and FIG. 2 shows the surface shape of the coining condition of 8 Japanese 100 yen white coins containing 75% Cu-25% Ni. As is clear from Table 1, the current Italian stainless steel for coins has a hardness of approximately Hv 163 in the annealed state. Coins made of steel have shallower and less clear patterns on their surfaces than Japanese 100 yen coins made of cupronickel. Although the depth of the coin engraving can be improved by increasing the pressure of the coining press, this is not economically advantageous as it shortens the life of the expensive die. As described above, it is understood that in order to fully utilize the various advantages of stainless steel as a material for coins, it is extremely important to first improve its hardness.
従来コイン用ステンレス鋼として開示されたものに特開
昭55−89431がある。この発明の要旨とするとこ
ろは、12〜18%のCrを含む7エライ1〜系ステン
レス鋼において、CrJ)外の添加元素量を可能な限り
低減したことと、素材の処理工程においてリジング性を
改善するために、その熱延に際して熱延仕上温度を80
0℃以下とし、巻取温度を450℃以下に限定した点に
ある。JP-A-55-89431 has been disclosed as a stainless steel for coins. The gist of this invention is to reduce the amount of added elements other than CrJ) as much as possible in 7-element 1-series stainless steel containing 12 to 18% Cr, and to improve ridging property in the material processing process. In order to improve the hot rolling process, the hot rolling finishing temperature was set at 80°C.
The main feature is that the winding temperature is limited to 0°C or lower, and the winding temperature is limited to 450°C or lower.
17かし、Cr以外の他の元素を低くすることは種々の
問題があり、例んばC,N含有量を低減させろことはコ
ストの上昇を招き、Siを低レベルに抑制することは脱
酸不足を生じコイン製造に重要な表面性状を劣化させる
こととなる。またリジング性の改善には熱延性」一温度
、巻取温度を低下させるのが有効であることは、特公昭
49−15696、特開昭52 668161.特公昭
58−56012等により公知の技術であるが、コイン
の巻取温度を450’3以下の低1品とすることば熱延
材のコインの形状を極端に悪くする結果となり、コイン
用ステンレス鋼として致命的欠陥となるおそれがある。17 However, there are various problems with reducing the content of other elements other than Cr. For example, reducing the content of C and N will increase costs, and suppressing Si to a low level is not an option. This causes a lack of acid and deteriorates the surface quality, which is important for coin production. Furthermore, in order to improve the ridging property, it is effective to lower the hot ductility temperature and the coiling temperature, as disclosed in Japanese Patent Publication No. 49-15696 and Japanese Patent Application Laid-Open No. 1982-668161. This is a technique known from Japanese Patent Publication No. 58-56012, etc., but if the coiling temperature of the coin is set to a low value of 450'3 or less, the shape of the hot-rolled coin becomes extremely poor. This may result in a fatal flaw.
本発明の目的はコイン用ステンレス鋼の如く冷間−fレ
ス成形等によって加工されるステンレス鋼の上記従来技
術の問題点を解決し、その最大の問題点である硬質性を
改善しHv 140以下の極軟質フエライ)・系ステン
レス鋼を提供するにある。The purpose of the present invention is to solve the above-mentioned problems of the conventional technology of stainless steel processed by cold-fless forming, such as stainless steel for coins, and to improve the hardness, which is the biggest problem, so that the hardness of the stainless steel is less than Hv 140. We provide ultra-soft stainless steel.
〔問題点を解決するための手段〕 本発明の上記の目的は次の2発明によって達成される。[Means for solving problems] The above objects of the present invention are achieved by the following two inventions.
第1発明の要旨とするところは次の如くである。すなわ
ら、
重量比にて C:0.03%未満
Si:0.30%以下
Mn:1.5%以下
P:0.04%以下
S:0.15%以下
Ni:1.0%以下
Cu:0.50%以下
Mo:0.60%以下
Cr: 11.5〜20%
N:0.03%以下
Al:0.005〜0.20%
を含有し、残部はFeおよび不可避的不純物より成り、
硬度がビッカース硬度スケールて140以下てあり圧印
加工性に侵れたことを特徴とする極軟質フェライト系ス
テンレス鋼である。The gist of the first invention is as follows. That is, in weight ratio: C: less than 0.03% Si: 0.30% or less Mn: 1.5% or less P: 0.04% or less S: 0.15% or less Ni: 1.0% or less Cu: 0.50% or less Mo: 0.60% or less Cr: 11.5-20% N: 0.03% or less Al: 0.005-0.20% The remainder is Fe and inevitable impurities. It consists of
It is an extremely soft ferritic stainless steel characterized by a hardness of 140 or less on the Vickers hardness scale and poor coining workability.
第2発明の要旨とするところは第1発明と同一基本組成
のほかに、更にTi:0.005〜020%、Nb:
o、o O5〜0.20%、v: 0005〜020
%の中から選ばれた1種以上を含み残部はFeおよび不
可避的不純物より成り、硬度がビッカース硬度スケール
で140以下であり圧印加工性に擾れたことを特徴とす
る極軟質フェライト系ステンレス鋼である。The gist of the second invention is that in addition to the same basic composition as the first invention, Ti: 0.005-020%, Nb:
o, o O5~0.20%, v: 0005~020
%, the remainder is Fe and unavoidable impurities, the hardness is 140 or less on the Vickers hardness scale, and the coining workability is poor. It is.
本発明者らは、フェライト系ステンレス鋼の軟質化を図
るに当って、先ずC,Si 、MnXPXS。In attempting to soften ferritic stainless steel, the present inventors first used C, Si, and MnXPXS.
Cr、 Ni 、Cu、 Mo、Nの10元素を種々の
レベル含有する87種類のフェライト系ステンレス鋼の
成分元素濃度と、結晶粒径がすべて20〜30μmとほ
ぼ一定のもとにおけるHv硬さとの相関分析を行った結
果下記の(1)式を得ることができた。The relationship between the component element concentration of 87 types of ferritic stainless steel containing various levels of the 10 elements Cr, Ni, Cu, Mo, and N and the Hv hardness when the grain size is all approximately constant at 20 to 30 μm. As a result of correlation analysis, the following equation (1) could be obtained.
Hv=73.3 12.3(5(C)+22.7(XS
i)→−0,8(2Mn)→−361(ZP)−551
(2S)+2.9 (j;Cr)+26 (XNi)+
9 、8 (XCu) + 5 、1 KMo) +
370 (1)−−−−411上記(1)式からSU
S 430に代表されろ通常のフェライト系ステンレス
鋼に含まれる各元素の濃度レベルと上記(1)式の係数
の大きさからHv硬さを低下させるためには、特にフェ
ライト系ステンレス鋼の主要元素としてSi 、P、
Cu 、、Mo、Nの5成分を規制すべきであることが
判明した。Hv=73.3 12.3(5(C)+22.7(XS
i) → -0,8 (2Mn) → -361 (ZP) -551
(2S)+2.9 (j;Cr)+26 (XNi)+
9, 8 (XCu) + 5, 1 KMo) +
370 (1)---411 From the above formula (1), SU
In order to reduce the Hv hardness based on the concentration level of each element contained in ordinary ferritic stainless steel, such as S430, and the magnitude of the coefficient in equation (1) above, it is necessary to As Si, P,
It was found that five components, Cu, Mo, and N, should be regulated.
ところで一般にCは便さを増加させる元素であるが、上
記(1)式ではむしろ負の係数を有している結果となっ
ている。この理由は、フェライト系ステンレス鋼の通常
の処理を経た後ではCはCr C等のCr炭化物とし
て析出しており、そのためC元素本来の固溶硬化作用は
生ぜず、むしろ固溶硬化作用を与えるCra度を実質的
に下げることを通して軟化作用を与えることによるもの
と考えられる。By the way, C is generally an element that increases convenience, but in the above equation (1), the result is that it has a rather negative coefficient. The reason for this is that after the normal treatment of ferritic stainless steel, C precipitates as Cr carbides such as CrC, so that the solid solution hardening effect inherent to C element does not occur, but rather gives a solid solution hardening effect. This is thought to be due to the fact that it provides a softening effect by substantially lowering the Cra degree.
本発明は上記の知見と、溶製時の経済性および素材の)
青浄度と表面性状を考慮して上記要旨の如く組成範囲を
限定することにより、極めて軟質なフェライト系ステン
レス鋼を安価に工業生産し得ることを見出し、本発明を
完成したものである。The present invention is based on the above knowledge, economical efficiency during melting, and material efficiency.
The present invention has been completed by discovering that extremely soft ferritic stainless steel can be industrially produced at low cost by limiting the composition range as outlined above in consideration of blue cleanliness and surface properties.
本発明によるフェライト系ステンレス鋼の成分限定理由
について説明する。The reason for limiting the composition of the ferritic stainless steel according to the present invention will be explained.
C:
Cは上記の如く、硬さに対しては従来一般に考えられて
いた点とは逆に、Cr炭化物生成を通じて軟化作用をも
つことが明らかになった。それ故Cは通常の添加レベル
においては硬さの観点から特に規制する必要はない。し
かし、一方貨幣に適用するに当っては約15〜20年と
される貨幣の流通寿命期間中の十分な耐食性を有するこ
とが要求される。C: As mentioned above, it has become clear that C has a softening effect on hardness through the formation of Cr carbides, contrary to what was generally thought in the past. Therefore, C does not need to be particularly regulated from the viewpoint of hardness at a normal addition level. However, when applied to coins, it is required to have sufficient corrosion resistance during the circulation life of coins, which is about 15 to 20 years.
貨幣の耐食性に最も影響を及ぼすのは汗であると考えら
れている。本梵明者らばSi:0.10%、Mn:0.
50%、P:O,001%、Cr:12.5%および1
75%、Aj:0.05%を含有し、かつ各Cr含有量
レベルにっきC含有量を0010〜0074%に変化さ
せたステンレス鋼を溶製し、その冷延焼純板の人工汗溶
液中の孔食電位を測定し、第3図にその結果を示した。Sweat is thought to have the greatest effect on the corrosion resistance of coins. If this is the case, Si: 0.10%, Mn: 0.
50%, P:O, 001%, Cr:12.5% and 1
75%, Aj: 0.05%, and the C content was changed from 0010 to 0074% at each Cr content level. The pitting potential was measured and the results are shown in FIG.
なお、比較のため現用のイタリアコイン用ステンレス鋼
の結果も同図においてO印で示した。For comparison, the results for the stainless steel currently in use for Italian coins are also shown with an O mark in the same figure.
孔食電位の測定は下記のようにして行った。The pitting potential was measured as follows.
すなわち、11の水中に7gのNaC1,1gの尿素、
4gの乳酸を含む人工汗溶液で基準電極としてSCE
(飽和甘木電厖)を使用してアノード分極試験を行った
。測定は35℃の前記人工汗溶液に試料を浸漬後SCE
による−500 mVで10分間保持後、自然浸漬電位
で更に10分間保持しt−後1分間当り20mV宛電位
全土げてIVになるまて掃引した。かくして得られたア
ノード分極曲線上で孔食の発生に伴って急激な溶解を開
始し溶解電流密度が100μA/ctに達する電位を孔
食電位とした。That is, 7 g of NaCl, 1 g of urea in 11 water,
SCE as a reference electrode with an artificial sweat solution containing 4 g of lactic acid.
(Saturated Amagi Denku) was used to perform an anode polarization test. The measurement was carried out by SCE after immersing the sample in the artificial sweat solution at 35°C.
After holding at -500 mV for 10 minutes, the natural immersion potential was held for another 10 minutes, and after t- the entire potential was swept at 20 mV per minute until it reached IV. On the thus obtained anode polarization curve, the potential at which rapid dissolution begins with the occurrence of pitting corrosion and the dissolution current density reaches 100 μA/ct was defined as the pitting corrosion potential.
第3図から人工汗溶液中の孔食電位はCr含有量によら
ずC含有量によって大きく影響されろことがわかるが、
良好な耐食性を得ろという観点からC含有量は本発明に
おいて003%未満に限定した。003%未満に限定す
ることにより175%Cr 含有レベルて現用の1′ク
リアコイン用ステンレス鋼と比較し優れた耐食性が得ら
れる。From Figure 3, it can be seen that the pitting corrosion potential in the artificial sweat solution is not affected by the Cr content, but is greatly influenced by the C content.
From the viewpoint of obtaining good corrosion resistance, the C content was limited to less than 0.03% in the present invention. By limiting the content to less than 0.003%, superior corrosion resistance can be obtained compared to the current stainless steel for 1' clear coins at a 175% Cr content level.
SI :
Siは溶製時の脱酸のため必須の成分であるが、硬度−
上昇作用が大きいために本発明ではAIによる脱酸を考
慮しSiを最少限に止め、その上限を030%に限定し
た。SI: Si is an essential component for deoxidizing during melting, but the hardness -
Since the increasing effect is large, in the present invention, in consideration of deoxidation by AI, Si is kept to a minimum and its upper limit is limited to 0.030%.
Mn ・
上記(1)式より明らかな如<、Mnは硬度を高める効
果が小さく、1%の添加によっても硬度上昇(よt(v
て1弱で、特に厳しく規制する必要がないが、15%を
越すと耐食性を劣化させるので上限を15%に限定した
。Mn - As is clear from the above formula (1), Mn has a small effect of increasing hardness, and even with the addition of 1%, the hardness increases (t(v)
It is a little less than 1, so there is no need to strictly regulate it, but if it exceeds 15%, corrosion resistance will deteriorate, so the upper limit was limited to 15%.
P :
Pは上記(1)式に示す如く硬さ上昇係数が361と非
常に大きいので極力低下することが好ましいが脱酸の経
済性との兼ね合いで004%以下に限定し1.: 。P: As shown in formula (1) above, P has a very large hardness increase coefficient of 361, so it is preferable to reduce it as much as possible, but in consideration of the economical efficiency of deoxidation, it is limited to 0.004% or less. :.
S :
Sは上記(1)式では負の係v!、を有しており、硬、
さの低減のt:めに高濃度の添加が望ましいが、Sが0
15%を越えて過多となると耐食性を低下させるので上
限を015%に限定した。S: S is a negative coefficient v! in the above equation (1). , hard,
It is desirable to add S at a high concentration to reduce t:
If the content exceeds 15%, the corrosion resistance will deteriorate, so the upper limit was set at 0.015%.
Ni 、Cu、 Mo:
上記(1)式のNi 、Cu 、 Moの)(v上昇係
数がそれぞれ26.9.8.5.1であることを考慮し
てこれら3元素のHv硬さの上昇の合計が約3以下にな
ることを目安として、N1ば10%以下、Cす:よ05
0%以下、Moは060%以下に限定した。Ni, Cu, Mo: Considering that the v increase coefficients of Ni, Cu, and Mo in equation (1) above are respectively 26.9.8.5.1, increase in Hv hardness of these three elements. As a guideline, the total of N1 is about 10% or less, and C: Yo05.
0% or less, and Mo was limited to 0.060% or less.
Cr :
Crはフェライト系ステンレス鋼の耐食性を維持するた
め最も重要な元素であり、11.5%未満では耐食性を
維持することができず、また20%を越して過多になる
と熱間加工性が劣化するので115〜20%の範囲に限
定した。Cr: Cr is the most important element for maintaining the corrosion resistance of ferritic stainless steel. If it is less than 11.5%, corrosion resistance cannot be maintained, and if it exceeds 20%, hot workability will deteriorate. Since it deteriorates, it is limited to a range of 115 to 20%.
N :
Nは上記(1)式におけるHv上昇係数が370と最大
であり低値とすることが望ましいが、本発明てはAI’
、 Ti % Nb 、 Vの適当屋を添加すること
によりNを窒化物として固定したのでコスト上昇を来さ
ない0.03%を上限とし003%以下に限定した。N: The Hv increase coefficient in the above formula (1) is 370, which is the maximum, and it is desirable to set it to a low value, but in the present invention, AI'
, Ti % Nb , and V were added to fix N as a nitride, so the upper limit was set at 0.03%, which does not increase costs, and was limited to 0.03% or less.
Al:
AIの適正量の添加は本発明における最も著しい特徴の
一つである。本発明におけるAIの作用は次の如くであ
る。Al: Addition of an appropriate amount of AI is one of the most remarkable features of the present invention. The action of AI in the present invention is as follows.
(イ) Hv硬さに最も大きく影響するNをAj’Nと
して固定して、その固溶硬化作用を無害化する。(a) N, which has the greatest influence on Hv hardness, is fixed as Aj'N to render its solid solution hardening effect harmless.
(0) Hv硬さ上昇作用の大きいSlを030%以
下に限定したことによる脱酸不十分を補い、かつ脱酸不
十分による清浄度劣化による表面性状の悪化を防止する
。(0) Compensate for insufficient deoxidation caused by limiting Sl, which has a large effect of increasing Hv hardness, to 0.30% or less, and prevent deterioration of surface properties due to deterioration of cleanliness due to insufficient deoxidation.
05〜3%のAIを含むフェライト系ステンレス鋼につ
いて、上記(1)式を求めt:のと同一手法でHv硬さ
に対するAIの係・数を求めた結果+61となり硬化作
用を有することが判明したが、一方05%以下のAIの
添加の場合、原子パーセントでN量の3倍以下のAIの
添加によって固溶窒素をAINとして固溶硬化作用を抑
制することができろ。しかし、固溶klの上記(11式
と同様のHv硬化係数が+61であることより必要以」
二の添加はHv硬さの上昇を招くので、上限を020%
とし、N量0.03%以下の規制との関連から下限をo
、oos%とし、o、oos〜0.20%の範囲に限定
した。For ferritic stainless steel containing 0.5 to 3% AI, the above equation (1) was calculated and the coefficient of AI to Hv hardness was calculated using the same method as t:.The result was +61, indicating that it has a hardening effect. However, in the case of adding 0.5% or less of AI, it is possible to suppress the solid solution hardening effect by converting solid solution nitrogen into AIN by adding AI in an amount not more than 3 times the amount of N in terms of atomic percent. However, since the Hv hardening coefficient of the solid solution kl (similar to Equation 11) is +61, it is not necessary.
The addition of 2 causes an increase in Hv hardness, so the upper limit is set to 0.20%.
In relation to the regulation of N content of 0.03% or less, the lower limit was set to o.
, oos%, and was limited to a range of o, oos to 0.20%.
上nF、C,Si、 Mn、 P、 S
X Ni 、 Cu、 Mo。Upper nF, C, Si, Mn, P, S
X Ni, Cu, Mo.
Cr、N、klの各限定量をもって本発明による極軟質
フェライト系ステンレス鋼の基本成分とするが、更にT
i、Nb、Vの下記限定量の1挿置」二を同時に含有す
る場合においても、本発明の目的をより有効に達成する
ことができる。これらの限定理由は次の如くである。Limited amounts of Cr, N, and Kl are the basic components of the ultra-soft ferritic stainless steel according to the present invention, and T
Even when the following limited amounts of i, Nb, and V are simultaneously contained, the objects of the present invention can be more effectively achieved. The reasons for these limitations are as follows.
Ti SNb XV:
本発明におけるTi、Nb5Vの作用は上記の如(Hv
硬さに最も大きく影響するNをその強力な窒化物形成作
用によりTiN、 NbN、 VNとして固定化し、そ
の固溶硬化作用を無害化することにある。これらの元素
を添加する場合はAIは脱酸のみを考慮した低レベルで
よいとし)う効果もある。Ti SNb XV: The action of Ti and Nb5V in the present invention is as described above (Hv
The purpose is to fix N, which has the greatest effect on hardness, as TiN, NbN, and VN through its strong nitride-forming action, and to render its solid solution hardening action harmless. When these elements are added, there is also the effect that AI may be kept at a low level considering only deoxidation.
7エライト系ステンレス鋼においては、耐食性向上の目
的で0.20〜060%のTi、Nb、、Vの添加が行
われることがある。この範gHのT1、Nb、、v量を
含むフエライ1−系ステン1/ス泪について、丘記(1
)式を求めたのと同一手法でHv硬さに対するこれら3
元素の係数を求めた結果、+112、+172、+74
と算出され大きな硬化作用を有することが判明した。し
かし02%以下のTi、Nb、Vの添加の場合、原子パ
ーセン)・てNzの約3@以下のTi、Nb、Vの添加
によって実質的に固溶窒素を窒化物として固溶硬化作用
を抑制ずろことができ、かつ著しい硬化作用を発揮ずろ
固溶Ti、Nb、Vを無視できるレベルに保つことがで
きることが判明した。In 7-elite stainless steel, 0.20 to 0.60% of Ti, Nb, and V are sometimes added for the purpose of improving corrosion resistance. Regarding the Ferrite 1-based stainless steel 1/S containing T1, Nb, , v amount in this range gH, Okaki (1
) for Hv hardness using the same method used to find the formula.
The results of calculating the coefficients of the elements are +112, +172, +74
It was calculated that it had a large hardening effect. However, when Ti, Nb, and V are added in an amount of 0.2% or less, the addition of Ti, Nb, and V in an amount of approximately 3% or less (atomic percent) and Nz substantially converts the solid solution nitrogen into nitrides, resulting in a solid solution hardening effect. It has been found that solid solution Ti, Nb, and V can be kept at negligible levels without exhibiting a significant hardening effect.
まr、: T iの添加は、溶製後の連続鋳造に際して
タンディツシュや浸6R管のノズル詰りを発生させ、ま
た地疵の発生頻度を高めるなどの問題点があるが、本発
明ではNを003%以下に限定しているのでTiを02
0%以下添加することにより、かかろ障害も防止できる
のでその上限を020%としtこ。The addition of Ti causes problems such as clogging of the nozzle of the tandish and immersion 6R pipe during continuous casting after melting, and increases the frequency of ground defects. However, in the present invention, the addition of N Since Ti is limited to 0.03% or less, Ti is
Adding 0% or less can prevent damage, so the upper limit is set at 0.20%.
またTi、Nb、■添加の上記効果1ii!!I量の7
・弧加量ても相応の効果が期待てきるが、実質的な効果
を得るt:めには少くとも0.005%を要するので、
それぞれ0005〜0.20%の範囲に限定17た。Also, the above effects 1ii of adding Ti, Nb, and ■! ! I quantity 7
・Although arc addition can be expected to have a corresponding effect, at least 0.005% is required to obtain a substantial effect.
Each was limited to a range of 0.0005% to 0.20%17.
フェライト系ステンレス鋼の主要元素含有量と硬さの関
係は前記(1)式で定板的に表わされることを明らかに
したが、本発明ではA1.Ti XNb 。It has been clarified that the relationship between the main element content and hardness of ferritic stainless steel is expressed as a fixed plate by the above equation (1), but in the present invention, A1. TiXNb.
■を適当撤添加ずろことにより強力な固溶硬化作用を有
t 71 N 全固定し、AI、 Ti ’t Nb、
V自身の固溶硬化も無視し得るレベルに保つことを可
能とした。この乙とにより+11式におけるNの項およ
びAI XTi 、 Nb、 Vの硬化作用を無視した
下記の硬さ指数HvNで実質的な硬さと成分の関係を表
示できることがわかった。By appropriately removing and removing ①, a strong solid solution hardening effect can be achieved.
This also made it possible to keep the solid solution hardening of V itself at a negligible level. It has been found that the relationship between the substantial hardness and the components can be expressed by the following hardness index HvN, which ignores the N term in Equation +11 and the hardening effects of AI XTi, Nb, and V.
硬さ指数HvN=73.3−12.3(XCrl+22
.7(XSi1+0.8 (XMn)+361 (zp
) −55,1KSI+ 2.9 (XCr)+ 2.
6 (zNi)+ 9.8 (XCu)+ 51 (X
Mo)−42)
本発明においては、既存の従来材と比較し、貨幣、メダ
ル、ゲーム用コインもしくは鍵等の圧印加工時の圧印圧
力が大幅に軽減できる値として(2)式の硬さ指数Hv
Nを140以下にすることが望ましい。Hardness index HvN=73.3-12.3 (XCrl+22
.. 7(XSi1+0.8 (XMn)+361 (zp
) -55,1KSI+ 2.9 (XCr)+ 2.
6 (zNi) + 9.8 (XCu) + 51 (X
Mo)-42) In the present invention, the hardness index of formula (2) is used as a value that can significantly reduce coining pressure during coining processing of coins, medals, game coins, keys, etc. compared to existing conventional materials. Hv
It is desirable that N be 140 or less.
上記各成分の限定要件を満し、残部はFeおよび不可避
的不純物より成り、更に好適には上記硬さ指数を満たす
フェライト系ステンレス鋼は、その最終の冷延焼純板の
Hv硬さで140以下を確保することが可能であり、従
来よりも著(7く軟質のフェライト系ステンレス鋼を得
ることができた。A ferritic stainless steel that satisfies the above-mentioned limiting requirements for each component, with the remainder consisting of Fe and unavoidable impurities, and more preferably satisfies the above-mentioned hardness index, has an Hv hardness of 140 or less in the final cold-rolled and sintered sheet. It was possible to obtain a ferritic stainless steel that was significantly softer than before.
本発明では最終の冷延後の焼鈍条件は特に規制(7ない
が、AIのみの添加材の場合、焼M >74度が約90
0℃以上になるとAlNの再固溶が生じ固溶窒素が増し
硬度上昇を生起させるため900℃未満の焼鈍が望まし
い。In the present invention, the annealing conditions after the final cold rolling are not particularly regulated (7), but in the case of an additive material containing only AI, the annealing M > 74 degrees is about 90 degrees.
When the temperature exceeds 0°C, re-solid solution of AlN occurs, and the amount of solid solute nitrogen increases, causing an increase in hardness. Therefore, annealing at a temperature of less than 900°C is desirable.
第1表に示す如きA−3の19種の本発明によるフェラ
イト系ステンレス鋼および比較鋼として5US430お
よびイタリアコイン用フェライト系ステンレス鋼と同質
ステンレス鋼および低炭素、低窒素であるが、T1また
はNbがそれぞれ0.36%、0.50%と本発明によ
る限定量よりも過度にTiXNbを含む7エライト系ス
テンレス鋼の比較鋼T、Uをいずれも同様に高周波真空
溶解炉で溶製し、それぞれ30kgの鋼塊とした。As shown in Table 1, 19 kinds of ferritic stainless steels of A-3 according to the present invention and comparative steels include 5US430 and stainless steels similar to ferritic stainless steels for Italian coins, and low carbon and low nitrogen, but T1 or Nb Comparative steels T and U, which are 7-elite stainless steels containing TiXNb in an amount of 0.36% and 0.50%, respectively, exceeding the limited amount according to the present invention, were similarly melted in a high-frequency vacuum melting furnace. It was made into a 30 kg steel ingot.
これらの鋼塊をいずれも同一条件で1250℃に加熱後
熱間圧延を行い3鴎厚の熱延板とした。All of these steel ingots were heated to 1250° C. under the same conditions and then hot-rolled to obtain hot-rolled sheets with a thickness of 3 mm.
その際の熱間圧延仕上温度は830℃であったっこの熱
延板を公知の方法により焼なまし、冷間圧延、仕上焼な
ましを行い1.2mm厚の冷延焼tie 5%板を得た
。The hot-rolled finish temperature at that time was 830°C. This hot-rolled plate was annealed by a known method, cold-rolled, and finished annealed to obtain a cold-rolled tie 5% plate with a thickness of 1.2 mm. Ta.
−aにコイン材としては12〜2.7mm厚の材料が使
用されるが、上記各工程処理を経ても本発明鋼および比
較鋼はいずれもリジングに伴う表面性状の劣化は見られ
ず、その後のテス)・コインの試作に当ってもなんらの
1−ラブルが発生しなかった。A material with a thickness of 12 to 2.7 mm is used as the coin material for -a, but even after the above-mentioned processes, neither the inventive steel nor the comparative steel showed any deterioration in surface quality due to ridging. No 1-ruble occurred during the prototype production of the Tess) coin.
従ってリジングに関して特別な条件で工程処理する必要
がないことが判明しt:。Therefore, it was found that there was no need to process the process under special conditions regarding ridging.
これらの各供試材についてHv硬さ、降伏応力、引張強
さおよび伸びの機械的性質を測定し、第1表に同時に示
した。第1表より明らかな如く、本発明鋼はHv硬さは
103〜138の範囲であり、比較鋼5tJS 430
の157、イタリアコイン用ステンレス鋼の163より
も著しく軟質となってし1ろことがわかる。比較鋼の硬
さが(2)式による硬さ指数と大きく異なる理由はこれ
らの鋼では固溶Nおよび固溶Ti、Nbが硬さに寄与し
ているためと考えられる。The mechanical properties of Hv hardness, yield stress, tensile strength, and elongation were measured for each of these test materials, and are also shown in Table 1. As is clear from Table 1, the Hv hardness of the steel of the present invention is in the range of 103 to 138, and that of the comparative steel 5tJS 430.
It can be seen that 157 is significantly softer than 163, the stainless steel used for Italian coins. The reason why the hardness of the comparative steels is significantly different from the hardness index determined by equation (2) is thought to be that in these steels, solid solution N, solid solution Ti, and Nb contribute to the hardness.
次に本発明のうちCr含有3112.5%クラスおよび
175%クラスの異なるCrレベルの代表鋼として供試
材B、、JおよびF、Lを取り挙げて、従来からコイン
用素材として広く使用されている白銅、黄銅、アルミニ
ウム、ニッケルを比較材として耐食性、耐摩耗性、コイ
ニング性の比較試験を行った。耐食性は上9己の人工汗
中の孔食電位によって評価した。なお、本発明鋼Fおよ
び比較材臼銅の耐食試験の人工汗溶液中のアノード分極
曲線をそれぞれ第4図、第5図に示しt:。Next, we will take up sample materials B, J, F, and L as representative steels with different Cr levels in the 3112.5% Cr content class and the 175% Cr class of the present invention. Comparative tests were conducted on corrosion resistance, abrasion resistance, and coining properties using comparative materials such as cupronickel, brass, aluminum, and nickel. Corrosion resistance was evaluated by pitting corrosion potential in artificial sweat. In addition, the anode polarization curves in the artificial sweat solution of the corrosion resistance test of the steel F of the present invention and the comparative mortar copper are shown in FIGS. 4 and 5, respectively.
また、耐摩耗試験は大越式耐摩耗試験機を用い、荷重3
.2kg、摩耗距gi66.6 m、 摩耗速度0、5
1 m/se cの条件で比摩耗量を測定した。In addition, the wear resistance test was carried out using an Okoshi type wear resistance tester, and a load of 3
.. 2 kg, wear distance gi 66.6 m, wear rate 0, 5
The specific wear amount was measured under the condition of 1 m/sec.
更にコイニング時の圧印力測定のために、本発明による
供試材B、F、J、I−および各比較材から25mmφ
のブランクを打抜き、これを圧線による耳付は後、ダイ
ス材質、IIS G4404による5KD11を使用
し圧印深さ250μmの条件でコインを作成し、周辺の
ぼりの発生、模様の彫りの状況から最適圧印力を測定し
た。Furthermore, in order to measure the coining force during coining, 25 mm
After punching out the blank and attaching the ears using a pressure wire, a coin was made using a die material of 5KD11 according to IIS G4404 with a coining depth of 250 μm, and the optimal coining was determined based on the occurrence of peripheral banners and the engraving of the pattern. The force was measured.
なお、比較材として使用した白銅は75%Cu−25%
Ni合金であり、黄銅は70%Cu −30%Zn合金
である。これら本発明鋼および比較材による耐食性、耐
摩耗性、最適圧印力によるコイニング性の比較試験Cよ
第2表に示すとおりである。The cupronickel used as a comparative material was 75% Cu-25%.
The brass is a 70% Cu-30% Zn alloy. Comparative test C of the corrosion resistance, abrasion resistance, and coining property using the optimum coining force of the steels of the present invention and comparative materials is as shown in Table 2.
第 2 表
、第2表より明らかな如く、本発明によるフェライト系
ステンレス鋼供試材B、FXJ、Lは他の比較材に比し
次の如きすぐれた特性を有している。As is clear from Tables 2 and 2, the ferritic stainless steel specimens B, FXJ, and L according to the present invention have the following superior properties compared to other comparative materials.
すなわち、
(イ)耐食性に関しては、本発明鋼は他の非鉄コイン材
料の白銅、黄銅、アルミニウム、ニッケルよりはるかに
すぐれ、5US430、イタリアコイン用ステンレス鍔
とほぼ同等である。That is, (a) In terms of corrosion resistance, the steel of the present invention is far superior to other nonferrous coin materials such as cupronickel, brass, aluminum, and nickel, and is almost equivalent to 5US430 and stainless steel tsuba for Italian coins.
(ロ)耐摩耗性についても、本発明鋼は非鉄コイン材料
の比較材およびイタリアコイン用ステンレユ鋼よりすぐ
れ、5Us43oとほぼ同等である。(b) Regarding wear resistance, the steel of the present invention is superior to comparative non-ferrous coin materials and stainless steel for Italian coins, and is almost equivalent to 5Us43o.
(ハ)コイン材等の冷間プレスによろ圧印加工に最も重
要な特性である最適圧印力に関しては、本発明鋼は耳付
は後焼鈍を施さなくとも303430、イタリアコイン
用ステンしス鋼等の他のフェライト系ステンレス鋼に比
し著しく低い値を示し、他の非鉄コイン材料の比較材に
比しても黄銅、ニッケルよりすぐれ、白銅、アルミニウ
ムの域に迫る低値にて、コイン用等の冷間てプレス成形
されろ用途に最適の材料であることを示している。これ
は第1表にて明らかにした本発明鋼の極軟質に、よる結
果である。(c) Regarding the optimum coining force, which is the most important characteristic for cold press filter coining of coin materials, etc., the steel of the present invention is 303430 without post-annealing, stainless steel for Italian coins, etc. It exhibits a significantly lower value than other ferritic stainless steels, and when compared to other comparative non-ferrous coin materials, it is superior to brass and nickel, and close to the level of cupronickel and aluminum, making it suitable for coins, etc. This indicates that the material is ideal for cold press forming applications. This result is due to the extremely soft nature of the steel of the present invention as shown in Table 1.
本発明によるフェライト系ステンレス鋼は適正な成分組
成を有し、特に極軟質および高耐食性とする本発明の目
的からSi 、 P、 Cu、 Mo、 Nを低減する
と同時に、klをo、oos〜0.20%とし、更に0
005〜020%のTi、Nb、Vを1種以上添加する
ことにより、NをAlNまたはTiN、NbN、VNと
して固定し、その固溶硬化作用を無害化し、併せてSi
不足による脱酸作用の不足を補う組成としたので次の如
き効果を挙げることができた。The ferritic stainless steel according to the present invention has an appropriate composition, and in particular, for the purpose of the present invention to make it extremely soft and highly corrosion resistant, Si, P, Cu, Mo, and N are reduced, and at the same time kl is reduced to o, oos ~ 0. .20% and then 0
By adding one or more of 005 to 020% of Ti, Nb, and V, N is fixed as AlN, TiN, NbN, and VN, its solid solution hardening effect is rendered harmless, and Si
Since the composition was designed to compensate for the lack of deoxidizing effect due to the deficiency, the following effects could be achieved.
(イ)硬さは極めて軟質であって、HvlOO〜140
を示し、その結果最適圧印力は極めて低い。(a) Hardness is extremely soft, HvlOO~140
, and as a result the optimum coining force is extremely low.
(ロ)耐食性、耐摩耗性についても、他の非鉄コイン材
料より著しくすぐれている。(b) Corrosion resistance and abrasion resistance are also significantly superior to other non-ferrous coin materials.
(ハ)/?i延祠の表面性状がすぐれている。(ha)/? i The surface quality of the engraving is excellent.
(ニ)製造コストが割安である。(d) Manufacturing costs are low.
(ホ)コイン材としてもイタリアコイン用フェライト系
ステンレス鋼よりすべての点ですぐれた最適材料である
。(e) As a coin material, it is an optimal material superior to ferritic stainless steel for Italian coins in all respects.
第1図はフェライト系ステンレス鋼を使用するイタリア
100リラ貨幣の表面および裏面形状の測定図、第2図
は75%Cu−25%Niの白銅を使用する日本の10
0円貨幣の表面および裏面形状の測定図、第3図は人工
汗溶液中の孔食電位と炭素含有量との関係を示す線図、
第4図は本発明鋼の実施例である供試材Fの耐食試験の
人工汗溶液中のアノード分極曲線図、第5図は比較材白
銅の第4図と同様の人工汗溶液中のアノード分極曲線図
である。Figure 1 is a measurement diagram of the front and back shapes of an Italian 100 lira coin made of ferritic stainless steel, and Figure 2 is a measurement diagram of the Japanese 100 lira coin made of 75% Cu-25% Ni cupronickel.
A measurement diagram of the front and back shapes of a 0 yen coin. Figure 3 is a diagram showing the relationship between pitting potential and carbon content in an artificial sweat solution.
Figure 4 is an anode polarization curve diagram in an artificial sweat solution for the corrosion resistance test of specimen F, which is an example of the steel of the present invention, and Figure 5 is an anode polarization curve in an artificial sweat solution similar to Figure 4 for comparative material cupronickel. It is a polarization curve diagram.
Claims (2)
硬度がビッカース硬度スケールで140以下であり圧印
加工性に優れたことを特徴とする極軟質フェライト系ス
テンレス鋼。(1) Weight ratio C: less than 0.03% Si: 0.30% or less Mn: 1.5% or less P: 0.04% or less S: 0.15% or less Ni: 1.0% or less Cu : 0.50% or less Mo: 0.60% or less Cr: 11.5-20% N: 0.03% or less Al: 0.005-0.20%, the remainder being Fe and unavoidable impurities. Becomes,
An extremely soft ferritic stainless steel characterized by a hardness of 140 or less on the Vickers hardness scale and excellent coining workability.
0.005〜0.20%、V:0.005〜0.20%
の中から選ばれた1種以上を含み残部はFeおよび不可
避的不純物より成り、硬度がビッカース硬度スケールで
140以下であり圧印加工性に優れたことを特徴とする
極軟質フェライト系ステンレス鋼。(2) Weight ratio C: less than 0.03% Si: 0.30% or less Mn: 1.5% or less P: 0.04% or less S: 0.15% or less Ni: 1.0% or less Cu : 0.50% or less Mo: 0.60% or less Cr: 11.5-20% N: 0.03% or less Al: 0.005-0.20%, and Ti: 0.005-0 .20%, Nb:
0.005-0.20%, V: 0.005-0.20%
An ultra-soft ferritic stainless steel characterized by containing one or more selected from the following, the remainder being Fe and unavoidable impurities, having a hardness of 140 or less on the Vickers hardness scale, and having excellent coining workability.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60-31020 | 1985-02-19 | ||
JP3102085 | 1985-02-19 | ||
JP60-77876 | 1985-04-12 |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6230852A true JPS6230852A (en) | 1987-02-09 |
Family
ID=12319836
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP61033480A Pending JPS6230852A (en) | 1985-02-19 | 1986-02-18 | Extra-soft ferritic stainless steel |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6230852A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010514928A (en) * | 2006-12-28 | 2010-05-06 | ポスコ | Ferritic stainless steel with excellent corrosion resistance and stretch formability and method for producing the same |
JP2018154858A (en) * | 2017-03-15 | 2018-10-04 | 日新製鋼株式会社 | Ti-CONTAINING FERRITIC STAINLESS STEEL HOT ROLLED STEEL STRIP AND MANUFACTURING METHOD OF STEEL STRIP |
-
1986
- 1986-02-18 JP JP61033480A patent/JPS6230852A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010514928A (en) * | 2006-12-28 | 2010-05-06 | ポスコ | Ferritic stainless steel with excellent corrosion resistance and stretch formability and method for producing the same |
JP2018154858A (en) * | 2017-03-15 | 2018-10-04 | 日新製鋼株式会社 | Ti-CONTAINING FERRITIC STAINLESS STEEL HOT ROLLED STEEL STRIP AND MANUFACTURING METHOD OF STEEL STRIP |
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