JPH0741923A - Production of hot dip galvanized steel sheet excellent in adhension of zinc layer and appearance - Google Patents
Production of hot dip galvanized steel sheet excellent in adhension of zinc layer and appearanceInfo
- Publication number
- JPH0741923A JPH0741923A JP18615593A JP18615593A JPH0741923A JP H0741923 A JPH0741923 A JP H0741923A JP 18615593 A JP18615593 A JP 18615593A JP 18615593 A JP18615593 A JP 18615593A JP H0741923 A JPH0741923 A JP H0741923A
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- Japan
- Prior art keywords
- bath
- plating
- steel sheet
- hot
- appearance
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】めっき密着性、外観性に優れた高
Ｓｉ系鋼溶融亜鉛めっき鋼板の製造法に関するものであ
る。[Field of Industrial Application] The present invention relates to a method for producing a high-Si steel hot-dip galvanized steel sheet having excellent plating adhesion and appearance.
【０００２】[0002]
【従来の技術】自動車や建材分野の軽量化や強度向上化
の動きを受け、高張力系表面処理鋼板の利用範囲は広が
っている。その中でも溶融亜鉛めっきした高張力鋼板は
特開昭６２−２３９７５号公報、特開昭６０−３３３１
８号公報のように高張力化を担う鋼成分が検討されてい
るが、同時にめっき性を阻害するＳｉ，Ｐ等の鋼中添加
量が比較的少量な範囲に制限されている。また溶融亜鉛
めっき鋼板は特公昭５６−１１３０９号公報、特公昭５
７−１５６６５号公報等多くの特許公報に紹介されてい
るように、被めっき材を酸化炉または無酸化炉で表面汚
れ、圧延油等を酸化燃焼させて除去した後、還元性雰囲
気中で加熱して表面酸化皮膜の還元と焼鈍を施しめっき
に適した温度に冷却しながらめっき浴に浸漬しめっき付
着量を調整するめっき作業を行い製造されている。さら
に合金化溶融亜鉛めっき鋼板は、続いて合金化炉でめっ
き層と被めっき材とを相互拡散させる合金化処理を施し
製造されている。2. Description of the Related Art The use range of high-tensile surface-treated steel sheets is expanding in response to the trend toward weight reduction and strength improvement in the fields of automobiles and building materials. Among them, hot-dip galvanized high-strength steel sheets are disclosed in JP-A-62-23975 and JP-A-60-3331.
Although the steel components responsible for increasing the tensile strength have been studied as in JP-A-8, at the same time, the addition amount of Si, P, etc., which hinders the plating property, in the steel is limited to a relatively small range. Hot-dip galvanized steel sheets are disclosed in Japanese Examined Patent Publication No. 56-11309 and Japanese Examined Patent Publication No. 5
As disclosed in many patent publications such as 7-15665, the material to be plated is subjected to oxidative combustion to remove surface stains, rolling oil, etc. in an oxidizing furnace or a non-oxidizing furnace, and then heated in a reducing atmosphere. Then, the surface oxide film is reduced and annealed, and the plate is soaked in a plating bath while being cooled to a temperature suitable for plating, and the plating work is adjusted to adjust the amount of the applied coating. Further, the alloyed hot-dip galvanized steel sheet is manufactured by subsequently subjecting it to an alloying treatment in an alloying furnace so that the plated layer and the material to be plated are mutually diffused.
【０００３】[0003]
【発明が解決しようとする課題】溶融亜鉛めっきおよび
合金化溶融亜鉛めっきした高張力鋼板は上述の如く、め
っき性を確保するために鋼中の低Ｓｉ化によって対応し
ているが、その反面、強度を含め材質を出しにくいとい
う材質設計の問題が生じている。本発明ではめっき密着
性と材質を両備し、かつ外観性に優れた高Ｓｉ系鋼溶融
亜鉛めっき鋼板の製造法を提供するものである。As described above, hot-dip galvanized and alloyed hot-dip galvanized high-strength steel sheets are dealt with by reducing the Si content in the steel in order to secure the plating property, but on the other hand, There is a problem in material design that it is difficult to produce materials including strength. The present invention provides a method for producing a high Si steel hot-dip galvanized steel sheet which has both plating adhesion and material and is excellent in appearance.
【０００４】[0004]
【課題を解決するための手段】本発明者らは高Ｓｉ鋼の
溶融亜鉛めっき鋼板の製造を目的に種々検討した結果、
鋼中に多量のＳｉを含有した被めっき材を使用し、弱酸
化させる雰囲気炉およびＦｅ酸化物を還元しうる雰囲気
炉の条件、浴への侵入条件、浴条件等の特定な操業条件
を組み合わせることによって目的とする溶融亜鉛めっき
鋼板が製造できることを知見した。As a result of various investigations by the present inventors for the purpose of producing a hot-dip galvanized steel sheet of high Si steel,
Using a material to be plated containing a large amount of Si in steel, combining specific operating conditions such as the conditions of an atmosphere furnace for weak oxidation and an atmosphere furnace for reducing Fe oxide, conditions for entering the bath, conditions for the bath, etc. It was found that the intended hot-dip galvanized steel sheet can be manufactured by this.
【０００５】その要旨は、Ｓｉを０．０１〜２．５％含
む焼鈍板を弱酸化性雰囲気炉で空気比０．８５〜１．５
０、板温３５０〜７００℃で加熱処理した後、Ｆｅ系酸
化物還元性雰囲気炉で５５０〜８００℃に加熱し続いて
板温３８０〜５２０℃に冷却しながら、浴温が４１０〜
５２０℃、浴中Ａｌを０．０５〜２０％を含有する溶融
亜鉛めっき浴中を通過させかつめっき付着量を調整する
めっき密着性、外観性に優れた溶融亜鉛めっき鋼板の製
造法である。The gist of the invention is that an annealed plate containing 0.01 to 2.5% of Si is used in a weak oxidizing atmosphere furnace at an air ratio of 0.85 to 1.5.
0, after heat treatment at a plate temperature of 350 to 700 ° C., while heating to 550 to 800 ° C. in a Fe-based oxide reducing atmosphere furnace and then cooling to a plate temperature of 380 to 520 ° C., a bath temperature of 410 to
This is a method for producing a hot-dip galvanized steel sheet excellent in plating adhesion and appearance in which a hot-dip galvanizing bath containing Al in the bath at 520 ° C. containing 0.05 to 20% is passed and a coating adhesion amount is adjusted.
【０００６】また、Ｓｉを０．０１〜２．５％含む焼鈍
板を弱酸化性雰囲気炉で空気比０．８５〜１．５０、板
温３５０〜７００℃で加熱処理した後、Ｆｅ系酸化物還
元性雰囲気炉で５５０〜８００℃に加熱し続いて板温４
００〜５２０℃に冷却しながら、浴温が４３０〜５２０
℃、浴中Ａｌを０．０５〜０．２０％を含有する溶融亜
鉛めっき浴中を通過させかつめっき付着量を調整しなが
らめっきを行った後板温４５０〜６００℃でめっき層中
のＦｅが５〜１５％に合金化処理するめっき密着性、外
観性に優れた溶融亜鉛めっき鋼板の製造法である。Further, an annealed plate containing 0.01 to 2.5% of Si is heat-treated in a weak oxidizing atmosphere furnace at an air ratio of 0.85 to 1.50 and a plate temperature of 350 to 700 ° C., and then Fe-based oxidation is performed. In a reducing atmosphere furnace, heat to 550-800 ° C and then plate temperature 4
While cooling to 00 to 520 ° C, the bath temperature is 430 to 520.
After passing through a hot dip galvanizing bath containing 0.05 to 0.20% of Al in the bath and adjusting the coating weight, the Fe in the plating layer was applied at a plate temperature of 450 to 600 ° C. Is a method for producing a hot-dip galvanized steel sheet excellent in plating adhesion and appearance, which is alloyed to 5 to 15%.
【０００７】以下に本発明について詳細に説明する。鋳
片を熱間圧延、酸洗、加熱等の処理を行って製造した焼
鈍板を被めっき材として亜鉛めっきを行い、又は更に合
金化処理をして巻き取る。このような溶融亜鉛めっき鋼
板を製造する。鋼成分として、Ｓｉは強度強化に非常に
有効な元素で目的材質を確保するために、０．０１％以
上の添加が必要である。しかし鋼中に２．５％を越えて
含有すると溶融めっき工程の操業条件を種々検討しても
加熱帯で被めっき材表面に生成するＳｉ系酸化皮膜が強
固となりめっき浴との反応性が低下して不めっきが発生
しやすくなる。またＳｉ含有量が多くなるに従って合金
化速度が低下し２．５％を越えると生産性が極端に落ち
る。従って鋼へのＳｉ含有量は２．５％以下とした。The present invention will be described in detail below. The annealed plate produced by subjecting the slab to hot rolling, pickling, heating, etc. is subjected to galvanization as a material to be plated, or further subjected to alloying treatment and wound. Such a galvanized steel sheet is manufactured. As a steel component, Si is a very effective element for strengthening strength, and it is necessary to add Si in an amount of 0.01% or more in order to secure a target material. However, if the content of Al exceeds 2.5% in the steel, the Si-based oxide film formed on the surface of the material to be plated in the heating zone becomes strong and the reactivity with the plating bath decreases even if the operating conditions of the hot dip plating process are variously examined. As a result, non-plating is likely to occur. Further, the alloying rate decreases as the Si content increases, and if it exceeds 2.5%, the productivity is extremely reduced. Therefore, the Si content in the steel is set to 2.5% or less.
【０００８】このような鋼成分の焼鈍板を被めっき材と
して使用する。焼鈍工程時に生成した酸化皮膜はめっき
密着性に悪影響を及ぼすため、酸化皮膜を酸洗等で一
旦、除去し溶融めっき工程を通板させる。酸洗後の被め
っき材表面はミクロ的にはＳｉ等の酸化物の残存や表面
形状の変化が起こり、これらを起点として溶融めっき工
程の加熱時にＳｉ等の局部的濃化が懸念される。従って
焼鈍板は表面状態起因のめっき密着性不良原因を除去す
る必要がありＳｉ等易酸化性元素の被めっき材表面への
濃化を防止する操業条件を設定しなければならない。ま
た焼鈍板を使用する為、材質は焼鈍工程で造りこまれて
おり、材質を大幅に変化させるような高温操炉条件は不
経済であり、比較的低温の操炉条件を設定する必要があ
る。An annealed plate of such a steel component is used as a material to be plated. Since the oxide film formed during the annealing process adversely affects the adhesion of the plating, the oxide film is once removed by pickling or the like, and the hot dipping process is performed. On the surface of the material to be plated after pickling, microscopically, oxides such as Si remain and the surface shape changes, which may cause local concentration of Si or the like during heating in the hot dip plating process. Therefore, it is necessary to remove the cause of poor plating adhesion due to the surface condition of the annealed plate, and the operating conditions must be set to prevent the concentration of easily oxidizable elements such as Si on the surface of the plated material. Also, since an annealed plate is used, the material is built in the annealing process, and high temperature operating conditions that change the material significantly are uneconomical, and it is necessary to set operating conditions at a relatively low temperature. .
【０００９】以下に各操業条件について述べる。弱酸化
性雰囲気炉−Ｆｅ系酸化物還元性雰囲気炉を有する溶融
めっきラインにおいて、弱酸化性雰囲気炉で空気比：
０．８５〜１．５，板温：３５０〜７００℃で被めっき
材を加熱する。弱酸化性雰囲気炉では被めっき材表面の
汚れ、圧延油等を燃焼除去すると共に、空気比（燃料を
完全に燃焼させるのに必要な理論空気量に対する空気量
の比率）と板温条件を調整することによって被めっき材
表面に生成する酸化皮膜の厚みと、生成する酸化皮膜の
質を制御できる。Each operating condition will be described below. In a hot dip coating line having a weak oxidizing atmosphere furnace-Fe-based oxide reducing atmosphere furnace, the air ratio in the weak oxidizing atmosphere furnace is:
The material to be plated is heated at 0.85 to 1.5 and plate temperature: 350 to 700 ° C. In a weak oxidizing atmosphere furnace, dirt on the surface of the material to be plated, rolling oil, etc. are burned and removed, and the air ratio (the ratio of the air amount to the theoretical air amount required to completely burn the fuel) and the plate temperature conditions are adjusted. By doing so, the thickness of the oxide film formed on the surface of the plated material and the quality of the oxide film formed can be controlled.
【００１０】空気比が０．８５未満では鋼中のＳｉ等の
易酸化性元素がＦｅと比較して優先的に酸化されやす
く、Ｓｉ等の易酸化性元素の酸化物が生成して難還元性
となる。空気比が大きくなるに従ってＳｉ等の易酸化性
元素と共に鋼の大部分をしめるＦｅも酸化されやすくな
りＦｅの酸化によってＳｉ等の鋼表面濃化が抑制されＦ
ｅ系酸化皮膜が主として生成する。When the air ratio is less than 0.85, easily oxidizable elements such as Si in steel are more likely to be preferentially oxidized than Fe, and oxides of easily oxidizable elements such as Si are generated to cause difficult reduction. It becomes sex. As the air ratio increases, Fe, which occupies most of the steel together with easily oxidizable elements such as Si, is easily oxidized, and the oxidation of Fe suppresses the enrichment of the steel surface such as Si.
An e-type oxide film is mainly formed.
【００１１】しかし空気比が１．５０を越えると、Ｆｅ
系酸化物が厚く生成し、還元工程時に十分にＦｅ系酸化
物を還元できずめっき性が低下する。従って空気比は
０．８５〜１．５０とした。板温は３５０℃未満である
と生成する酸化皮膜量は極めて少ないが、次のＦｅ系酸
化物還元雰囲気炉でＦｅ系酸化物が還元されてくると被
めっき材に含まれるＳｉ等の易酸化性元素の表面濃化が
促進されめっき性を阻害する。７００℃を越える温度で
は被めっき材表面に生成する酸化皮膜量が厚くなると共
に、還元工程条件では十分にＦｅ系酸化物を還元できず
めっき性を阻害する。また次のＦｅ系酸化物還元炉で被
めっき材の温度が高くなりすぎ、材質面に影響を及ぼ
す。従って板温は３５０〜７００℃とした。However, when the air ratio exceeds 1.50, Fe
The system oxide is thickly formed, and the Fe system oxide cannot be reduced sufficiently during the reduction step, and the plating property is deteriorated. Therefore, the air ratio is 0.85 to 1.50. If the plate temperature is less than 350 ° C., the amount of oxide film produced is extremely small, but when the Fe-based oxide is reduced in the next Fe-based oxide reducing atmosphere furnace, it easily oxidizes Si and the like contained in the material to be plated. The surface concentration of the volatile element is promoted and the plating property is hindered. If the temperature exceeds 700 ° C., the amount of oxide film formed on the surface of the material to be plated becomes thick, and the Fe-based oxide cannot be sufficiently reduced under the conditions of the reducing step, which hinders the plating property. Further, the temperature of the material to be plated becomes too high in the next Fe-based oxide reduction furnace, which affects the material surface. Therefore, the plate temperature was set to 350 to 700 ° C.
【００１２】続いてＦｅ系酸化物を還元しうる雰囲気炉
で５５０〜８００℃に再加熱する。熱延板のような焼鈍
板を使用するため、本加熱炉では再結晶させる必要はな
く弱酸化性雰囲気炉で生成したＦｅ系酸化物を最適還元
させてめっき浴との反応性を確保することが必要であ
る。また炉内はＦｅ系酸化物が十分に還元可能な低露
点、低Ｏ2 濃度、Ｈ2 を含む不活性ガス雰囲気にする必
要がある。Then, it is reheated to 550 to 800 ° C. in an atmosphere furnace capable of reducing the Fe-based oxide. Since an annealing plate such as a hot rolled plate is used, it is not necessary to recrystallize in this heating furnace, and the Fe-based oxide generated in the weak oxidizing atmosphere furnace is optimally reduced to ensure reactivity with the plating bath. is necessary. In addition, it is necessary to make the inside of the furnace an inert gas atmosphere containing a low dew point, a low O 2 concentration, and H 2 that can sufficiently reduce the Fe-based oxide.
【００１３】５５０℃未満ではＦｅ系酸化物の還元速度
が遅くＦｅ系酸化物が残存しめっき性を低下させる。８
００℃を越えるとＦｅ弱酸化性雰囲気炉で生成したＦｅ
系酸化物が還元され、被めっき材に含まれるＳｉ等の易
酸化性元素が濃化し難還元性皮膜を生成する。また材質
面へ影響を及ぼす。従って、めっき性確保に必要なＦｅ
系酸化皮膜の酸化−還元バランスのとれた条件の確保、
および溶融めっき工程で再結晶させない条件として、５
５０〜８００℃の加熱温度とＦｅ酸化物を還元しうる雰
囲気とした。If the temperature is lower than 550 ° C., the reduction rate of the Fe-based oxide is slow, and the Fe-based oxide remains and deteriorates the plating property. 8
When the temperature exceeds 00 ° C, Fe generated in a furnace with a weak oxidizing atmosphere
The system oxide is reduced, and easily oxidizable elements such as Si contained in the material to be plated are concentrated to form a difficult-to-reduce film. It also affects the material. Therefore, Fe, which is necessary to secure the plating property,
Securing a well-balanced oxidation-reduction condition for the system oxide film,
And 5 as a condition not to recrystallize in the hot dipping process
The heating temperature was 50 to 800 ° C. and the atmosphere was such that Fe oxide could be reduced.
【００１４】次に冷却して溶融亜鉛めっき浴に浸漬す
る。溶融亜鉛めっき鋼板の場合、侵入板温：３８０〜５
２０℃，浴温：４１０〜５２０℃、浴中Ａｌ：０．０５
〜２０％とする。これらの因子は被めっき材と浴との反
応性、光沢等の外観性を左右する。侵入板温が３８０℃
未満の場合被めっき材と浴との反応性が大幅に低下しＦ
ｅ−Ａｌ−Ｚｎ系合金層の成長が抑制されると共に、連
続通板されるので浴温が低下しめっき後の外観にも悪影
響を及ぼす。５２０℃を越えると浴と被めっき材との反
応性が高まり合金層が厚く生成して加工時のめっき密着
性を低下させる傾向になると共に、連続通板すると浴が
徐々に上昇し操業上の問題を生ずる。従って侵入板温は
３８０〜５２０℃とした。Then, it is cooled and immersed in a hot dip galvanizing bath. In the case of hot-dip galvanized steel sheet, penetration plate temperature: 380-5
20 ° C, bath temperature: 410-520 ° C, Al in the bath: 0.05
-20%. These factors affect the reactivity between the material to be plated and the bath and the appearance such as gloss. Penetration plate temperature is 380 ℃
If it is less than F, the reactivity between the material to be plated and the bath is significantly reduced and F
The growth of the e-Al-Zn alloy layer is suppressed, and since the plate is continuously threaded, the bath temperature lowers and the appearance after plating is adversely affected. When the temperature exceeds 520 ° C, the reactivity between the bath and the material to be plated increases and the alloy layer is thickly formed, which tends to lower the plating adhesion during processing, and when continuously threaded, the bath gradually rises to improve the operation. Cause problems. Therefore, the penetration plate temperature was set to 380 to 520 ° C.
【００１５】浴温は４１０℃未満だと浴の粘性が高まり
付着量制御やめっき後の外観を低下させる。また被めっ
き材との反応性も大きく低下し不めっきを発生しやす
い。５２０℃を越える場合、浴と被めっき材との反応性
が高まり合金層が成長しやすくなり加工時のめっき密着
性が低下する。また浴の蒸発が促進されスナウト内壁等
に大きな付着物をつくる。付着物は振動等で落下しスト
リップに付着してめっき後の外観に悪影響を及ぼす。更
にポット出側時の板温が高くなりトップロールに到達ま
での冷却速度を早めれば成らず光沢ムラ等の外観不良を
きたす。従って浴温は４１０〜５２０℃とした。When the bath temperature is less than 410 ° C., the viscosity of the bath increases and the control of the amount of adhesion and the appearance after plating are deteriorated. Also, the reactivity with the material to be plated is greatly reduced, and non-plating is likely to occur. If it exceeds 520 ° C., the reactivity between the bath and the material to be plated increases, the alloy layer easily grows, and the plating adhesion during processing decreases. In addition, evaporation of the bath is promoted and large deposits are formed on the inner wall of the snout. The deposits fall due to vibrations, etc. and adhere to the strip, which adversely affects the appearance after plating. Further, the plate temperature on the outlet side of the pot becomes high, and it cannot be achieved by increasing the cooling rate until reaching the top roll, resulting in poor appearance such as uneven gloss. Therefore, the bath temperature was set to 410 to 520 ° C.
【００１６】浴中Ａｌ濃度は０．０５％未満であるとめ
っき浴中での合金層成長が著しくなりめっき付着量制御
が困難となることおよび加工時のめっき密着性の点でも
好ましくない。また亜鉛めっき後の光沢を低下させる。
２０％を越えてＡｌが添加されると浴の融点が大幅に上
昇しそれとともに合金層が急激に成長し、操業条件の大
幅な変更およびめっき密着性が低下するため浴中Ａｌ濃
度を０．０５〜２０％とした。このようにして溶融亜鉛
めっき鋼板を製造する。When the Al concentration in the bath is less than 0.05%, the growth of the alloy layer in the plating bath becomes remarkable, which makes it difficult to control the coating amount and it is not preferable in terms of the plating adhesion during processing. It also reduces the gloss after galvanizing.
When Al is added in excess of 20%, the melting point of the bath rises sharply, the alloy layer grows rapidly with it, the operating conditions are greatly changed, and the plating adhesion is lowered. It was set to 05 to 20%. Thus, a hot dip galvanized steel sheet is manufactured.
【００１７】さらに合金化溶融亜鉛めっき鋼板を製造す
る場合、再加熱処理後侵入板温：４００〜５２０℃，浴
温：４３０〜５２０℃、浴中Ａｌ：０．０５〜０．２０
％とする。これらの因子は被めっき材と浴との反応性を
左右する。侵入板温は４００℃未満だと被めっき材と浴
との反応性が大幅に低下しＦｅ−Ａｌ−Ｚｎ系合金層の
成長が抑制されると共に被めっき材が連続通板されるの
で浴温が低下しめっき後の外観にも悪影響を及ぼす。５
２０℃を越えると浴と被めっき材との反応性が高まりＦ
ｅ−Ａｌ−Ｚｎ系合金層が減少しＦｅ−Ｚｎ系合金層が
増加し耐パウダリング性を低下させる。Further, when an alloyed hot-dip galvanized steel sheet is produced, after the reheating treatment, the penetration plate temperature is 400 to 520 ° C., the bath temperature is 430 to 520 ° C., and the Al in the bath is 0.05 to 0.20.
%. These factors influence the reactivity between the material to be plated and the bath. If the penetration plate temperature is less than 400 ° C., the reactivity between the material to be plated and the bath is significantly reduced, the growth of the Fe—Al—Zn alloy layer is suppressed, and the material to be plated is continuously passed through the bath temperature. Deteriorates and adversely affects the appearance after plating. 5
If the temperature exceeds 20 ° C, the reactivity between the bath and the material to be plated increases and F
The e-Al-Zn alloy layer decreases and the Fe-Zn alloy layer increases, and the powdering resistance decreases.
【００１８】従って侵入板温は４００〜５２０℃とし
た。浴温は４３０℃未満だと浴の粘度が高まり付着量制
御性やめっき後の外観を低下させる。また被めっき材と
の反応性も低下する。５２０℃を越える場合、浴と被め
っき材との反応性が高まりＦｅ−Ａｌ−Ｚｎ系合金層が
減少しＦｅ−Ｚｎ系合金層が増加して耐パウダリング性
が低下する。従って浴温は４３０〜５２０℃とした。Therefore, the penetration plate temperature was set to 400 to 520 ° C. If the bath temperature is less than 430 ° C., the viscosity of the bath increases and the controllability of the adhesion amount and the appearance after plating deteriorate. Also, the reactivity with the material to be plated is reduced. If the temperature exceeds 520 ° C, the reactivity between the bath and the material to be plated increases, the Fe-Al-Zn alloy layer decreases, the Fe-Zn alloy layer increases, and the powdering resistance decreases. Therefore, the bath temperature was 430 to 520 ° C.
【００１９】浴中Ａｌ濃度は０．０５％未満であるとめ
っき浴中での合金層成長が著しくなりめっき付着量制御
が困難となることおよび耐パウダリング性の点でも好ま
しくない。まためっき浴中Ａｌ濃度が増加すると合金化
を抑制するＦｅ−Ａｌ−Ｚｎ系合金層の量が増加し合金
化炉での合金化に際しより高温度で長時間の処理が必要
となり生産性を阻害する。従って浴中Ａｌ濃度は０．０
５〜０．２０％とした。If the Al concentration in the bath is less than 0.05%, the growth of the alloy layer in the plating bath becomes remarkable, which makes it difficult to control the coating amount and it is also unfavorable from the viewpoint of powdering resistance. In addition, when the Al concentration in the plating bath increases, the amount of Fe-Al-Zn alloy layer that suppresses alloying increases, and when alloying in an alloying furnace, higher temperature and longer treatment are required, which impedes productivity. To do. Therefore, the Al concentration in the bath is 0.0
It was set to 5 to 0.20%.
【００２０】さらに溶融亜鉛めっき浴からでてきたスト
リップは付着量を制御し合金化炉へ入る。合金化炉では
板温４５０〜６００℃でめっき層中のＦｅが５〜１５％
に生成するように加熱する。４５０℃未満ではめっき層
中へ被めっき材のＦｅを拡散含有させるのに時間がかか
り、Ｆｅ拡散させることによって被めっき材とめっき層
の密着性をさらに向上させるには不十分である。６００
℃を越えると被めっき材とめっき層間の反応が充分に促
進されるが、耐パウダリング性に有害な合金層が厚く生
成するため、加熱温度を４５０〜６００℃とした。Further, the strips coming out of the hot dip galvanizing bath enter the alloying furnace while controlling the deposit amount. In the alloying furnace, Fe in the plating layer is 5 to 15% at a plate temperature of 450 to 600 ° C.
Heat to produce. If the temperature is lower than 450 ° C, it takes time to diffuse and contain Fe of the plated material in the plated layer, and it is insufficient to further improve the adhesion between the plated material and the plated layer by diffusing Fe. 600
When the temperature exceeds ℃, the reaction between the material to be plated and the plating layer is sufficiently promoted, but a thick alloy layer detrimental to the powdering resistance is formed. Therefore, the heating temperature was set to 450 to 600 ° C.
【００２１】めっき層中のＦｅが５％未満であると、合
金化が十分でなく外観ムラ、めっき密着性不良等が発生
しやすい。１５％を越える場合、過合金となり逆にパウ
ダリング等の密着性不良が発生しやすい。従って合金化
溶融亜鉛めっき鋼板のめっき密着性、外観性を確保する
合金化処理条件として板温４５０〜６００℃でめっき層
中のＦｅを５〜１５％になるように合金化処理する。When the Fe content in the plating layer is less than 5%, alloying is not sufficient and uneven appearance and poor plating adhesion are likely to occur. If it exceeds 15%, it becomes an overalloy, and conversely, poor adhesion such as powdering is likely to occur. Therefore, as an alloying treatment condition for ensuring the plating adhesion and appearance of the alloyed hot-dip galvanized steel sheet, Fe is alloyed at a plate temperature of 450 to 600 ° C. so that Fe in the plating layer becomes 5 to 15%.
【００２２】[0022]
【実施例】以下に本発明の実施例を述べる。表１に検討
鋼成分値を記す。本成分を有する鋳片を熱延し、更に酸
洗、冷延さらに焼鈍、酸性し被めっき材を作成した。 実施例１ 標記鋼成分を有する焼鈍板の被めっき材（表１）を使用
し無酸化炉（ＮＯＦ）−還元炉（ＲＴＦ）方式の連続溶
融亜鉛めっきラインにて表２に示す操業条件を設定して
溶融亜鉛めっきし、付着量を５５ｇ／ｍ2 に制御した
後、合金化処理を行い合金化溶融亜鉛めっき鋼板を製造
した。このような本発明範囲の条件の基で製造した合金
化溶融亜鉛めっき鋼板は不めっきの発生もなく外観、め
っき密着性も良好で操業上も特別な問題はなかった（表
２）。一方比較条件の基で製造した合金化溶融亜鉛めっ
き鋼板は微小不めっきや未アロイが発生し外観が損なわ
れたり、めっき密着性が不良であった（表２）。EXAMPLES Examples of the present invention will be described below. Table 1 shows the studied steel composition values. A slab containing this component was hot-rolled, then pickled, cold-rolled, annealed, and acidified to prepare a material to be plated. Example 1 The operating conditions shown in Table 2 were set in a continuous hot dip galvanizing line of a non-oxidizing furnace (NOF) -reducing furnace (RTF) system using a material to be plated (Table 1) for an annealed plate having the title steel component. Then, hot dip galvanizing was performed, and the amount of adhesion was controlled to 55 g / m 2 , and then alloying treatment was performed to manufacture an alloyed hot dip galvanized steel sheet. The alloyed hot-dip galvanized steel sheet produced under the conditions of the range of the present invention did not cause non-plating, had good appearance and plating adhesion, and had no special problems in operation (Table 2). On the other hand, the galvannealed steel sheet produced under the comparative conditions had microscopic unplating or unalloying, impaired the appearance, and had poor plating adhesion (Table 2).
【００２３】[0023]
【表１】 [Table 1]
【００２４】[0024]
【表２】 [Table 2]
【００２５】＊外観 ◎ 肉眼で不めっきなし △ 微小不めっきあり または未アロイ部分が残る。 × 小さな不めっきあり ＊めっき密着性 角筒プレス（ブランク径１５０×１５０ｍｍ、深さ２５
ｍｍ）を行い、めっき剥離量を測定しさらに付着量で割
った値を剥離面積とした。 １：２〜 ７ｃｍ2 ４：１７〜２２ｃｍ2 ２：７〜１２ｃｍ2 ５：２２〜 ３：１２〜１７ｃｍ2 * Appearance ◎ No non-plating with the naked eye △ Fine non-plating or unalloyed parts remain. × Small non-plating * Plating adhesion Square tube press (Blank diameter 150 × 150 mm, depth 25
mm), the amount of plating peeling was measured, and the value obtained by dividing the amount by the amount of adhesion was defined as the peeling area. 1: 2~ 7cm 2 4: 17~22cm 2 2: 7~12cm 2 5: 22~ 3: 12~17cm 2
【００２６】実施例２ 標記鋼成分を有する焼鈍板の被めっき材（表１）を使用
し無酸化炉（ＮＯＦ）−還元炉（ＲＴＦ）方式の連続溶
融亜鉛めっきラインにて表３に示す操業条件を設定して
溶融亜鉛めっきし、付着量を１００ｇ／ｍ2 に制御して
溶融亜鉛めっき鋼板を製造した。このような本発明範囲
の条件のもとで製造した溶融亜鉛めっき鋼板は不めっき
の発生もなく外観、めっき密着性も良好で操業上も特別
な問題はなかった（表３）。一方、比較条件の基で製造
した溶融亜鉛めっき鋼板は微小不めっきや外観不均一部
が発生し外観が損なわれたり、めっき密着性が不良であ
った（表３）。Example 2 An operation shown in Table 3 in a continuous hot dip galvanizing line of a non-oxidizing furnace (NOF) -reducing furnace (RTF) system using a material to be plated (Table 1) for an annealed plate having the above-mentioned steel composition. The hot-dip galvanized steel sheet was manufactured by setting the conditions and hot-dip galvanizing and controlling the adhesion amount to 100 g / m 2 . The hot-dip galvanized steel sheet produced under the conditions of the range of the present invention did not cause non-plating, had good appearance and plating adhesion, and had no special problems in operation (Table 3). On the other hand, the hot-dip galvanized steel sheet produced under the comparative conditions had microscopic unplating or uneven appearance, impaired the appearance, and had poor plating adhesion (Table 3).
【００２７】[0027]
【表３】 [Table 3]
【００２８】＊外観 ◎ 肉眼で不めっきなし △ 微小不めっきあり または外観不均一部が発生 × 小さな不めっきあり ＊めっき密着性 Ｖ時曲げ（角度６０°）を行い、加工部のめっき剥離具
合を評価した。 ◎ 全く剥離なし △ 微小剥離あり × 小さな剥離あり* Appearance ◎ No non-plating with the naked eye △ Fine non-plating or uneven appearance occurs × Small non-plating * Plating adhesion Bending (angle 60 °) at V evaluated. ◎ No peeling at all △ Fine peeling × Small peeling
【００２９】[0029]
【発明の効果】以上述べたように、本発明によって製造
された溶融亜鉛めっき鋼板は不めっきの発生もなく外
観、めっき密着性も良好で操業上も特別な問題なく製造
することが出来る優れた効果を奏するものである。As described above, the hot-dip galvanized steel sheet manufactured according to the present invention is excellent in appearance and plating adhesion without occurrence of non-plating and can be manufactured without any special problems in operation. It is effective.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ２２Ｃ 38/02 (72)発明者 末永 真 福岡県北九州市戸畑区飛幡町１番１号 新 日本製鐵株式会社八幡製鐵所内 (72)発明者 亀田 正春 福岡県北九州市戸畑区飛幡町１番１号 新 日本製鐵株式会社八幡製鐵所内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI Technical indication location C22C 38/02 (72) Inventor Makoto Suenaga 1-1 No. 1 Hibatacho, Tobata-ku, Kitakyushu, Fukuoka (72) Inventor, Masaharu Kameda 1-1 Tobahata-cho, Tobata-ku, Kitakyushu, Fukuoka Prefecture New Nippon Steel Co., Ltd., Yawata Works
Claims (2)
弱酸化性雰囲気炉で空気比０．８５〜１．５０、板温３
５０〜７００℃で加熱処理した後、Ｆｅ系酸化物還元性
雰囲気炉で５５０〜８００℃に加熱し続いて板温３８０
〜５２０℃に冷却しながら、浴温が４１０〜５２０℃、
浴中Ａｌを０．０５〜２０％を含有する溶融亜鉛めっき
浴中を通過させかつめっき付着量を調整することを特徴
とするめっき密着性、外観性に優れた溶融亜鉛めっき鋼
板の製造法。1. An annealed plate containing 0.01 to 2.5% of Si in a weak oxidizing atmosphere furnace with an air ratio of 0.85 to 1.50 and a plate temperature of 3.
After heat treatment at 50 to 700 ° C., it is heated to 550 to 800 ° C. in a Fe-based oxide reducing atmosphere furnace, and then the plate temperature is 380.
While cooling to ~ 520 ° C, the bath temperature is 410-520 ° C,
A method for producing a hot-dip galvanized steel sheet having excellent plating adhesion and appearance, which comprises passing Al in a hot-dip galvanizing bath containing 0.05 to 20% and adjusting a coating amount.
弱酸化性雰囲気炉で空気比０．８５〜１．５０、板温３
５０〜７００℃で加熱処理した後、Ｆｅ系酸化物還元性
雰囲気炉で５５０〜８００℃に加熱し続いて板温４００
〜５２０℃に冷却しながら、浴温が４３０〜５２０℃、
浴中Ａｌを０．０５〜０．２０％を含有する溶融亜鉛め
っき浴中を通過させかつめっき付着量を調整しながらめ
っきを行った後板温４５０〜６００℃でめっき層中のＦ
ｅが５〜１５％に合金化処理することを特徴とするめっ
き密着性、外観性に優れた溶融亜鉛めっき鋼板の製造
法。2. An annealed plate containing 0.01 to 2.5% of Si in a weak oxidizing atmosphere furnace with an air ratio of 0.85 to 1.50 and a plate temperature of 3.
After heat treatment at 50 to 700 ° C., it is heated to 550 to 800 ° C. in a Fe-based oxide reducing atmosphere furnace, and then the plate temperature is 400.
While cooling to ~ 520 ° C, the bath temperature is 430-520 ° C,
After passing through a hot dip galvanizing bath containing 0.05 to 0.20% of Al in the bath and performing plating while adjusting the coating amount of F, F in the plating layer at a plate temperature of 450 to 600 ° C.
A method for producing a hot-dip galvanized steel sheet excellent in plating adhesion and appearance, characterized by performing an alloying treatment to e of 5 to 15%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18615593A JPH0741923A (en) | 1993-07-28 | 1993-07-28 | Production of hot dip galvanized steel sheet excellent in adhension of zinc layer and appearance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18615593A JPH0741923A (en) | 1993-07-28 | 1993-07-28 | Production of hot dip galvanized steel sheet excellent in adhension of zinc layer and appearance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0741923A true JPH0741923A (en) | 1995-02-10 |
Family
ID=16183349
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18615593A Withdrawn JPH0741923A (en) | 1993-07-28 | 1993-07-28 | Production of hot dip galvanized steel sheet excellent in adhension of zinc layer and appearance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0741923A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001323355A (en) * | 2000-05-11 | 2001-11-22 | Nippon Steel Corp | Si-CONTAINING HIGH-STRENGTH HOT-DIP GALVANIZED STEEL SHEET AND COATED STEEL SHEET, EXCELLENT IN PLATING ADHESION AND CORROSION RESISTANCE AFTER COATING, AND ITS MANUFACTURING METHOD |
| JP2010189734A (en) * | 2009-02-19 | 2010-09-02 | Kobe Steel Ltd | Method for producing high strength hot dip galvannealed steel sheet |
| US20120186707A1 (en) * | 2009-07-29 | 2012-07-26 | Jfe Steel Corporation | Method for manufacturing of high strength cold rolled steel sheet of excellent phosphatability |
| CN102758143A (en) * | 2011-04-25 | 2012-10-31 | 宝山钢铁股份有限公司 | Hot-dip galvanized steel sheet with tensile strength higher than 1180MPa, and manufacturing method thereof |
-
1993
- 1993-07-28 JP JP18615593A patent/JPH0741923A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001323355A (en) * | 2000-05-11 | 2001-11-22 | Nippon Steel Corp | Si-CONTAINING HIGH-STRENGTH HOT-DIP GALVANIZED STEEL SHEET AND COATED STEEL SHEET, EXCELLENT IN PLATING ADHESION AND CORROSION RESISTANCE AFTER COATING, AND ITS MANUFACTURING METHOD |
| JP2010189734A (en) * | 2009-02-19 | 2010-09-02 | Kobe Steel Ltd | Method for producing high strength hot dip galvannealed steel sheet |
| US20120186707A1 (en) * | 2009-07-29 | 2012-07-26 | Jfe Steel Corporation | Method for manufacturing of high strength cold rolled steel sheet of excellent phosphatability |
| US8668789B2 (en) * | 2009-07-29 | 2014-03-11 | Jfe Steel Corporation | Method for manufacturing of high strength cold rolled steel sheet of excellent phosphatability |
| CN102758143A (en) * | 2011-04-25 | 2012-10-31 | 宝山钢铁股份有限公司 | Hot-dip galvanized steel sheet with tensile strength higher than 1180MPa, and manufacturing method thereof |
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