JPH03191047A - Manufacture of alloyed hot-dip galvanized steel sheet having excellent press formability - Google Patents
Manufacture of alloyed hot-dip galvanized steel sheet having excellent press formabilityInfo
- Publication number
- JPH03191047A JPH03191047A JP32720389A JP32720389A JPH03191047A JP H03191047 A JPH03191047 A JP H03191047A JP 32720389 A JP32720389 A JP 32720389A JP 32720389 A JP32720389 A JP 32720389A JP H03191047 A JPH03191047 A JP H03191047A
- Authority
- JP
- Japan
- Prior art keywords
- steel sheet
- hot
- less
- dip
- steel
- 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 229910001335 Galvanized steel Inorganic materials 0.000 title abstract description 4
- 239000008397 galvanized steel Substances 0.000 title abstract description 4
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 75
- 239000010959 steel Substances 0.000 claims abstract description 75
- 238000005275 alloying Methods 0.000 claims abstract description 24
- 238000011282 treatment Methods 0.000 claims abstract description 14
- 238000000137 annealing Methods 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims abstract description 9
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 5
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 5
- 238000007747 plating Methods 0.000 claims description 32
- 230000003647 oxidation Effects 0.000 claims description 9
- 238000007254 oxidation reaction Methods 0.000 claims description 9
- 239000010960 cold rolled steel Substances 0.000 claims description 5
- 238000007654 immersion Methods 0.000 claims description 4
- 230000035515 penetration Effects 0.000 claims description 2
- 229910001209 Low-carbon steel Inorganic materials 0.000 abstract description 3
- 229910052799 carbon Inorganic materials 0.000 abstract description 3
- 229910052748 manganese Inorganic materials 0.000 abstract description 3
- 238000005246 galvanizing Methods 0.000 abstract 4
- 238000000227 grinding Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 230000003111 delayed effect Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000004566 building material Substances 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000008595 infiltration Effects 0.000 description 2
- 238000001764 infiltration Methods 0.000 description 2
- 238000010422 painting Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 1
- 241001125046 Sardina pilchardus Species 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 235000019512 sardine Nutrition 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Landscapes
- Coating With Molten Metal (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、自動車車体用表面処理鋼板として使用される
、めっき外観が美麗でかつプレス成形性に優れた合金化
溶融Ｚｎめっき鋼板に関するものである。[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an alloyed hot-dip Zn-plated steel sheet that is used as a surface-treated steel sheet for automobile bodies and has a beautiful plating appearance and excellent press formability. be.
〈従来の技術〉
一般的に、合金化溶融Ｚｎめっき鋼板は、溶融Ｚｎめっ
きを施した後、合金化炉でＺｎの融点以上に加熱してめ
っき層をＦｅとＺｎの合金、即ち鋼板側から「、δ５、
この各相からなる合金層としたものである。この合金化
溶融Ｚｎめっき鋼板は、優れた塗装後耐食性及び溶接性
を兼備しているため、自動車、家電、建材用素材として
多用されている。家電、建材等では比較的軽度の加工で
使用されるが、自動車等では厳しい絞り加工が行われる
。また、車体の安全性向上、車体重量軽減等から、この
絞り加工性と共に高強度を兼ね備えた鋼板の要求が強ま
っている。このため、自動車用として高強度高加工性を
必要とするものについては、低炭素鋼に高強度をもちプ
レス成形性を付与する目的で、Ｔｉ及びＮｂ等、更に、
これにＰを添加した冷延ｍＪ５ｉで対処しているのが一
般的である。<Prior art> In general, alloyed hot-dip Zn-plated steel sheets are processed by hot-dip Zn plating and then heated in an alloying furnace to a temperature higher than the melting point of Zn to form an alloy of Fe and Zn, that is, from the steel sheet side. ``, δ5,
The alloy layer is made up of each of these phases. This alloyed hot-dip Zn-plated steel sheet has excellent post-painting corrosion resistance and weldability, and is therefore widely used as a material for automobiles, home appliances, and building materials. It is used for relatively light processing in home appliances, building materials, etc., but severe drawing processing is performed in automobiles, etc. Furthermore, in order to improve the safety of car bodies, reduce the weight of cars, etc., there is an increasing demand for steel plates that have both drawing workability and high strength. For this reason, for automobiles that require high strength and high workability, Ti and Nb are added to low carbon steel in order to give it high strength and press formability.
This is generally dealt with by cold-rolled mJ5i to which P is added.
しかし、このＰ添加鋼板は、一般の冷延鋼板に比べめっ
き条件（鋼板表面の酸化状態や露点、浴中へ！、浸入板
温等）の影響も受けやすく、合金化処理で合金化の進行
が遅滞し、パウダリング不良や焼けむらが発生しやすい
。However, this P-added steel sheet is more susceptible to plating conditions (oxidation state and dew point of the steel sheet surface, entering the bath, temperature of the sheet entering the bath, etc.) than general cold-rolled steel sheets, and alloying progresses during alloying treatment. is delayed, resulting in poor powdering and uneven baking.
溶融Ｚｎめっき鋼板の製造においては、生産性の向上あ
るいは設備のコンパクト化が可能なこと等の点から、無
酸化炉又は酸化炉（以下ＮＯＦと呼ぶ）を具えたゼンジ
マ一方式が主流である。この方式は無酸化炉あるいは酸
化炉で鋼板表面を弱酸化し、その後還元焼鈍してＺｎめ
っきすることを特徴としているが、上記に述べたＰ添加
鋼板は、このＮＯＦを具えたゼンジマ一方式では、−層
めっき条件の影響を受けやすく、高品質な合金化溶融Ｚ
ｎめっき鋼板を得るための合金処理範囲が狭い。In the production of hot-dip Zn-plated steel sheets, the Sendzima type, which is equipped with a non-oxidation furnace or an oxidation furnace (hereinafter referred to as NOF), is mainstream from the viewpoint of improving productivity and making equipment more compact. This method is characterized by mildly oxidizing the surface of the steel sheet in a non-oxidizing furnace or an oxidizing furnace, followed by reduction annealing and Zn plating. - High quality alloyed fusion Z that is easily influenced by layer plating conditions
The alloy processing range for obtaining n-plated steel sheets is narrow.
Ｐ添加鋼板の合金化溶融Ｚｎめっき鋼板の製造に関し、
例えば特公昭６４−１１１１１号公報に開示しであるよ
うに、浴中Ａｃ４度と浴温を鋼中Ｐ、Ｓｉｉによって規
制し、合金化速度をコントロールする方法や特公平１−
２８０９７号公報のように、浴中Ａｃ４度と鋼中Ｐ濃度
の関係式を求め、得られた係数がある値以下となるよう
に、Ａ１９４度を調整してめっきし、１次、２次の合金
化処理をしてめっき加工性、化成処理性を改善する方法
等が提案されている。Regarding the production of alloyed Zn-plated steel sheets of P-added steel sheets,
For example, as disclosed in Japanese Patent Publication No. 64-11111, there is a method in which the alloying rate is controlled by regulating the AC4 degree in the bath and the bath temperature by P and Sii in the steel, and
As in Publication No. 28097, the relational expression between the Ac4 degree in the bath and the P concentration in the steel is determined, and the A194 degree is adjusted and plated so that the obtained coefficient is below a certain value, and the primary and secondary Methods have been proposed to improve plating workability and chemical conversion treatment through alloying treatment.
〈発明が解決しようとする課題〉
上記のように、Ｐ添加！４Ｉｉは、一般の冷延鋼板に比
べめっき条件（鋼表面の酸化状態や雰囲気ガスの露点、
浴中ＡＩ、浸入板温等）の影響を受けやすく、合金化処
理で合金化の進行が遅滞し、パウダリング不良や焼けむ
らが発生しやすい。即ち、自動車用として高品質な合金
化溶融Ｚｎめっきａ板を得るための合金化処理範囲が狭
いという問題点がある。<Problem to be solved by the invention> As mentioned above, P addition! 4Ii has lower plating conditions (oxidation state of the steel surface, dew point of atmospheric gas,
It is easily affected by the AI in the bath, the temperature of the immersed plate, etc.), and the progress of alloying is delayed during alloying treatment, resulting in poor powdering and uneven baking. That is, there is a problem that the range of alloying treatment for obtaining high quality alloyed hot-dip Zn-plated A-sheets for automobiles is narrow.
また、前記の特公昭６４−１１１１１号公報、特公平１
２８０９７号公報に提案されている対策によって、ある
程度めっき特性は改善されるものの、浴温の制ｍあるい
は１次、２次の合金化処理は、実ライン操業において生
産性が劣るという欠点がある。In addition, the above-mentioned Japanese Patent Publication No. 11111/1983, Japanese Patent Publication No. 1
Although the measures proposed in Publication No. 28097 improve the plating properties to some extent, controlling the bath temperature or primary and secondary alloying treatments have the drawback of poor productivity in actual line operation.
本発明は、このような問題を解決した合金化溶融Ｚｎめ
っき鋼板の製造方法を提供することを目的とする。An object of the present invention is to provide a method for manufacturing an alloyed hot-dip Zn-plated steel sheet that solves these problems.
く課題を解決するための手段〉
Ｐ添加鋼を素材とした合金化溶融Ｚｎめっき鋼板は、め
っき外観が劣り、安定したパウダリング性が得られにく
い、こればＰ添加鋼板は鋼中Ｐが高いこと、まためっき
時の焼鈍過程で鋼板表面にＰが濃化することに起因する
と推定された０本発明は、この知見に基づいて完成した
ものである。Means to solve the problem〉 Alloyed Zn-plated steel sheets made from P-added steel have poor plating appearance and are difficult to obtain stable powdering properties.This means that P-added steel sheets have a high P content in the steel. The present invention was completed based on this knowledge, which was presumed to be caused by the concentration of P on the surface of the steel sheet during the annealing process during plating.
即ち本発明は、Ｃ： ０．０２ｗｔ％以下、Ｓｉ ：
０．１ｗｔ％以下、Ｍｎ： ０．７ｗｔ％以下、Ｐ
： ０．２ｎｔ％以下、Ｎ ： ０．０１ｗｔ％以
下、ＡＩ ： ０．１０ｗｔ％以下、Ｔｉを単独又は月
とＮｂを合計で０．１ｗｔ％以下を含有する冷延鋼板表
面に溶融Ｚｎめっき後、合金化処理を行う合金化溶融Ｚ
ｎめっき鋼板の製造方法において、鋼板を酸化炉又は無
酸化炉を経ることなく、ｎｚ１５％以上、露点＋５℃以
下の還元性雰囲気中で、７００〜９００ ’Ｃの温度で
焼鈍後、０，１０〜０．１４ｗｔ％の八！を含有する溶
融Ｚｎめっき浴中で、鋼中Ｐ含有量に応じた下式の浸入
板温Ｔで溶融Ｚｎめっき後、合金化処理を行うことを特
徴とするプレス成形性に優れた合金化溶融Ｚｎめっき鋼
板の製造方法である。That is, in the present invention, C: 0.02 wt% or less, Si:
0.1wt% or less, Mn: 0.7wt% or less, P
: 0.2 nt% or less, N: 0.01 wt% or less, AI: 0.10 wt% or less, after hot-dip Zn plating on the surface of a cold rolled steel sheet containing Ti alone or 0.1 wt% or less of moon and Nb in total. , alloying melting Z that performs alloying treatment
In the method for producing n-plated steel sheet, the steel sheet is annealed at a temperature of 700 to 900'C in a reducing atmosphere with NZ of 15% or more and a dew point of +5°C or less without passing through an oxidation furnace or a non-oxidation furnace. ~0.14wt% of eight! Alloying melting with excellent press formability characterized by performing alloying treatment after hot-dip Zn plating at the penetration plate temperature T according to the following formula according to the P content in the steel in a hot-dip Zn plating bath containing This is a method for manufacturing a Zn-plated steel sheet.
（５００Ｐ ＋４８０）−２０≦Ｔ≦（５００Ｐ ＋
４８０） ＋ ２０但し、Ｔ：浸入板温 ℃
Ｐ：ｔｉｌ仮中Ｐ含有量 −１％
く作 用〉
以下に本発明を具体的に説明する。まず、素材成分の限
定理由について詳述する。(500P +480)-20≦T≦(500P +
480) +20 However, T: immersion plate temperature °C P: til temporary medium P content -1% Effect> The present invention will be specifically explained below. First, the reasons for limiting the material components will be explained in detail.
ＣＴＣは鋼中に不可避的不純物元素として含有され、銅
板のプレス成形性を阻害する元素である。CTC is an element that is contained in steel as an unavoidable impurity element and inhibits the press formability of copper plates.
Ｔｉを添加しＴｔＣとして鋼中に固定されれば、その害
は著しく軽減されるものの０．０２ｗｔ％超では、Ｔｉ
ＣとしてＣを固定するのに必要なＴｉｌが増し、かつ多
量にＴｉＣが鋼中に分離することによる材質劣化が著し
いため０．０２ｉｙｔ％以下とする。If Ti is added and fixed in steel as TtC, the harm will be significantly reduced, but if it exceeds 0.02wt%, Ti
The amount of Ti required for fixing C increases, and a large amount of TiC separates into the steel, resulting in significant material deterioration, so it is set at 0.02 iyt% or less.
Ｓｉミニ−に鋼中３１は溶融金属との濡れ性を阻害し、
不めっき欠陥の発生を助長する。０．１ｗＬ％超含有す
ると不めっき欠陥が発生しゃすくなるので、Ｓｉの」二
限は０．１ｗｔ％とする。Steel medium 31 inhibits wettability with molten metal in Si mini-
Promotes the occurrence of non-plating defects. If the content exceeds 0.1 wL%, non-plating defects are likely to occur, so the upper limit of Si is set to 0.1 wt%.
Ｍｎ ： Ｍｎは鋼板の強度を確保する固溶強化元素と
し添加するが、Ｐと共存する場合、Ｍｎを０．７４％超
えて添加すると、伸びの減少が著しくなるので０．７ｗ
Ｌ％以下に限定した。Mn: Mn is added as a solid solution strengthening element to ensure the strength of the steel sheet, but when it coexists with P, if it is added in excess of 0.74%, the elongation decreases significantly, so 0.7w
It was limited to L% or less.
Ｐ：ＰもＭｎと同様、固溶強化元素として添加するが、
０．２ｗｔ％を超えると鋼板の脆化（加工性の劣化）が
起こるので、上限をＱ、２ｗｔ％とした。P: Like Mn, P is also added as a solid solution strengthening element,
If it exceeds 0.2 wt%, the steel plate will become brittle (deterioration of workability), so the upper limit was set to Q, 2 wt%.
Ｎ ： Ｎ ４．＞ Ｃと同様、鋼中に不可避的不純物
として含有され、かつ鋼板のプレス成形性を阻害する。N: N4. > Like C, it is contained in steel as an unavoidable impurity and inhibits the press formability of steel sheets.
Ｔｉ及びＴ目−Ｎｂ添加鋼ではＴｉＮとして固定されて
おり、プレス成形性を阻害することはないが、ＡｌをＴ
ｉＮとして固定するために必要なＴｉ添加量が増大しコ
ストアップとなる。したがってＡｌを０．０１ｗｃ％以
下とする。In steel with Ti and T-Nb addition, it is fixed as TiN and does not impede press formability, but when Al is
The amount of Ti added necessary for fixing as iN increases, resulting in an increase in cost. Therefore, Al should be 0.01wc% or less.
Ａｔ ： ／Ｖは鋼中にＴｉ又はＮｂを添加する際に脱
酸剤として使用することにより、Ｔｉ、 Ｎｂの歩留り
向上と７青浄な表面を得るため有効である。しかし、Ａ
Ｉが０．１ｗｔ％超では鋼板の延性が劣化するため０．
１ｗｔ％以下とする。By using At:/V as a deoxidizing agent when adding Ti or Nb to steel, it is effective to improve the yield of Ti and Nb and to obtain a blue surface. However, A
If I exceeds 0.1 wt%, the ductility of the steel plate will deteriorate;
The content shall be 1 wt% or less.
Ｔｉ ： Ｔｉを鋼中に添加することにより、Ｃ，Ａｌ
をそれぞれＴｉＣ，ＴｉＮとして固定し、これら不純物
元素が鋼板のプレス成形性に及ばず悪影響を消滅せしめ
、高い延性と高７値を有する鋼板を製造することが可能
である。しかし、０．１ｗｔ％鰯のＴｉを添加すると、
合金化処理における焼けむら発生の原因となるので上限
を０．１ｗｔ％とする。Ti: By adding Ti to steel, C, Al
are fixed as TiC and TiN, respectively, and these impurity elements do not affect the press formability of the steel plate and eliminate the adverse effects, making it possible to produce a steel plate with high ductility and high 7 value. However, when adding 0.1 wt% sardine Ti,
Since it causes uneven burning during alloying treatment, the upper limit is set to 0.1 wt%.
Ｎｂ ： ＮｂもＴｉと同様な働きをし、高い延性と高
ｒ値を得るのに必要な元素である。Ｎｂの添加量は特に
規制しないが、Ｎｂ＋Ｔｉが０．１ｗｔ％超になると、
常温で鋼板の延性が低下しプレス成形性を阻害するので
、Ｎｂ＋Ｔｉ添加量として０．１ｗｔ％以下に限定する
。Nb: Nb also functions in the same way as Ti, and is an element necessary to obtain high ductility and high r value. The amount of Nb added is not particularly regulated, but if Nb + Ti exceeds 0.1 wt%,
Since the ductility of the steel sheet decreases at room temperature and inhibits press formability, the amount of Nb+Ti added is limited to 0.1 wt% or less.
以上述べたＰ添加鋼板を素材に、Ｉｌ、 ｉｓ％以上、
露点＋５℃以下の還元性雰囲気中で７００〜９００ ’
Ｃの温度で焼鈍後、０．１０〜０．１４ｗｔ％のＭを含
むＺｎめっき浴で、鋼中Ｐ量に応じて、（５００Ｐ ＋
４８０） −２０≦Ｔ≦（５００Ｐ ＋４８０） ＋
２０ （Ｔ ：浸入板温’Ｃ，，Ｐ＝鋼中Ｐｗｔ％）の
浸入板温でめっきし、合金化処理すれば、めっき外観な
らびに耐パウダリング性の優れた合金化溶融Ｚｎめっき
鋼板が得られる。Using the P-added steel sheet described above as a material, Il, is% or more,
700-900' in a reducing atmosphere with a dew point of +5℃ or less
After annealing at a temperature of C, (500P +
480) -20≦T≦(500P +480) +
By plating and alloying at an immersion plate temperature of 20 (T: immersion plate temperature 'C, P = Pwt% in steel), an alloyed hot-dip Zn-coated steel sheet with excellent coating appearance and powdering resistance can be obtained. It will be done.
既に述べたように、Ｐ添加鋼板は一般の冷延鋼板に比べ
合金化の進行が遅滞し、パウダリング不良や焼けむらが
発生しやすい。As already mentioned, the progress of alloying in P-added steel sheets is delayed compared to general cold-rolled steel sheets, and powdering defects and uneven burning are likely to occur.
これらの現象が起こる理由についてはまだ十分解明され
ていないが、めっき層を調べると、鋼板表面にＰが濃化
し、しかも健全なへ！冨化層が形成されていないことが
わかった。Ｐ添加鋼板を素材にした合金化溶融Ｚｎめっ
き鋼板が安定製造できないのは、直接的にはＰ濃化に起
因したＡＩ冨化層の形成不全によると推定された。これ
から、Ｐ添加鋼板をＮＯＦを保有するゼンジマ一方式で
Ｚｎめっきすると、ＮＯＦおよび続く還元焼鈍の露点に
よっては、Ｐはｗ４板より酸化雰囲気である鋼板表面に
濃化し、結果的に不健全なＡＩ冨化層の形成に至ったと
考えられる。そこでＰ添加鋼板は、鋼板表面に酸化膜を
できるだけ形成しないことが有利と考え、ＮＯＦを経る
ことなく、■、１５％以上、露点＋５℃以下の還元雰囲
気中で７００〜９００℃の温度で焼鈍し、０．１０−０
．１４ｗｔ％Ａ！を含有するＺｎめっき浴で鋼中Ｐ量に
よって管理した浸入板温でめっきし、合金化処理すれば
、めっき外観、耐パウダリング性の優れた合金化溶融Ｚ
ｎめっき鋼板が安定して製造できる。The reason why these phenomena occur is not fully understood yet, but when we examine the plating layer, we find that P is concentrated on the surface of the steel sheet, and it is healthy! It was found that no enriched layer was formed. The reason why alloyed hot-dip Zn-plated steel sheets made from P-added steel sheets cannot be stably produced is thought to be directly due to insufficient formation of the AI-enriched layer due to P concentration. From now on, when a P-added steel sheet is Zn-plated using the Sendzima method that contains NOF, depending on the NOF and the dew point of the subsequent reduction annealing, P will be more concentrated on the steel sheet surface, which is in an oxidizing atmosphere, than on the W4 sheet, resulting in unhealthy AI. It is thought that this led to the formation of an enriched layer. Therefore, P-added steel sheets are annealed at a temperature of 700 to 900℃ in a reducing atmosphere of 15% or more and a dew point of +5℃ or less, without going through NOF. , 0.10-0
．． 14wt%A! By plating and alloying in a Zn plating bath containing Zn at a temperature controlled by the amount of P in the steel, alloyed molten Z has excellent plating appearance and powdering resistance.
N-plated steel sheets can be stably produced.
還元焼鈍の雰囲気がＨ２１５％未満、露点＋５℃超の低
１１□濃度高露点では鋼中Ｐにとっては酸化領域になり
やすいこと、また、焼鈍温度を７００〜９００℃に限定
したのは、７００℃未満では再結晶が不充分となり、９
００℃超では、相変態し、Ｙ値の劣化、延性の低下が起
こるためである。The reason for limiting the annealing temperature to 700 to 900°C is because the reduction annealing atmosphere is likely to become an oxidation region for P in the steel at low 11□ concentrations and high dew points with H2 less than 15% and dew point exceeding +5°C. If it is less than 9, recrystallization will be insufficient.
This is because, if the temperature exceeds 00°C, phase transformation occurs, resulting in a deterioration of the Y value and a decrease in ductility.
浴中へ！は、−Ｃの冷延鋼板と同じ０．１０〜０．１４
ｗｔ％、即ち、浴中へ！濃度は変えずに、鋼中ＰＪＩに
よって浸入板温を調整することでＰ添加鋼板の合金化条
件を見出したものである。浴中ＡＺを下限０．１０−Ｅ
％としたのは、この濃度未満ではめっき時に「が形成し
やすく、合金化溶融Ｚｎめっき鋼板とした時にパウダリ
ング性が著しく劣るためである。Into the bath! is 0.10 to 0.14, which is the same as -C cold rolled steel plate.
wt%, that is, into the bath! The alloying conditions for P-added steel sheets were found by adjusting the infiltration plate temperature by PJI in the steel without changing the concentration. Lower limit of AZ in bath 0.10-E
% because if the concentration is less than this, it will be easy to form during plating, and the powdering property will be significantly poor when used as an alloyed hot-dip Zn-plated steel sheet.
また、浸入ヰ反４ｉＴが（５００Ｐ ＋４８０） −２
０℃（Ｐ：鋼中ＰｓＬ％）未満では、Ｍ富化層が必要以
上に厚く形成しやすく、また（５００ Ｐ ＋ ４８０
） ＋ ２０ ’Ｃ超では、逆にへ！冨化層が不均一に
形成しやすく、結果的にめっき外観、耐パウダリング性
の優れた合金化処理範囲が著しく狭くなる。Also, the infiltration resistance is (500P +480) -2
Below 0°C (P: PsL% in steel), the M-enriched layer tends to be formed thicker than necessary, and (500 P + 480
) + 20 'C, on the other hand, to! The enriched layer tends to be formed non-uniformly, and as a result, the range of alloying treatment that provides excellent plating appearance and powdering resistance is significantly narrowed.
以上述べたように、Ｐ添加鋼板を素材に合金化溶融Ｚｎ
めっき鋼板を製造するには、還元焼鈍温度、雰囲気ガス
を管理し、浴中Ａ！濃度を変えずに鋼中Ｐｇに応して浸
入板温を調整すれば、めっき外観及び耐パウダリング性
に優れた製品が得られる。As mentioned above, alloyed molten Zn is produced using P-added steel sheet as a raw material.
To produce plated steel sheets, the reduction annealing temperature and atmospheric gas are controlled, and A! By adjusting the infiltrated plate temperature according to the Pg in the steel without changing the concentration, a product with excellent plating appearance and powdering resistance can be obtained.
〈実施例〉 本発明の実施例を以下に説明する。<Example> Examples of the present invention will be described below.
第１表に示す素材組成のＰ添加鋼板を用いて、還元性雰
囲気中で鋼中ＰＩに応じて浸入板温を変えてＺｎめっき
した場合のＡＩ冨化層及びめっき密着性の調査結果を第
２表に、また第２表と同一条件でめっき後合金化処理し
て同様にめっき特性（めっき層構造、Ｆｅ％、パウダリ
ング性）を調べた結果を第３表に示した。The results of the investigation of the AI enriched layer and plating adhesion when P-added steel sheets with the material composition shown in Table 1 were coated with Zn in a reducing atmosphere and the plate temperature was varied according to the PI in the steel. Table 2 and Table 3 show the results of similarly examining the plating properties (plating layer structure, Fe%, powdering property) after the plating was alloyed under the same conditions as in Table 2.
〈発明の効果〉
近年、自動車用表面処理鋼板として塗装後耐食性及び溶
接性等が優れている合金化溶融Ｚｎめっき鋼板の使用が
増大しており、Ｐ添加鋼板は、合金化処理溶融Ｚｎめっ
き鋼板としてめっき外観が損なわれ、安定したプレス成
形性が得られにくいが、以上説明したように、本発明に
よるめっき条件でめっきし合金化処理すれば、自動車用
表面処理鋼板として高品質合金化溶融Ｚｎめっき鋼板の
製造が可能であり、これによって益々需要拡大が期待で
きる。<Effects of the Invention> In recent years, the use of alloyed hot-dip Zn-plated steel sheets, which have excellent post-painting corrosion resistance and weldability, has been increasing as surface-treated steel sheets for automobiles. However, as explained above, if the plating and alloying treatment according to the present invention is carried out under the plating conditions of the present invention, high-quality alloyed molten Zn can be used as a surface-treated steel sheet for automobiles. It is possible to manufacture galvanized steel sheets, and this is expected to further increase demand.
Claims (1)
ｎ：０．７ｗｔ％以下、Ｐ：０．２ｗｔ％以下、Ｎ：０
．０１ｗｔ％以下、Ａｌ：０．１０ｗｔ％以下、Ｔｉを
単独又はＴｉとＮｂを合計で０．１ｗｔ％以下を含有す
る冷延綱板表面に溶融Ｚｎめっき後、合金化処理を行う
合金化溶融Ｚｎめっき鋼板の製造方法において、鋼板を
酸化炉又は無酸化炉を経ることなく、Ｈ＿２１５％以上
、露点＋５℃以下の還元性雰囲気中で、７００〜９００
℃の温度で焼鈍後、０．１０〜０．１４ｗｔ％のＡｌを
含有する溶融Ｚｎめっき浴中で、鋼板中Ｐ含有量に応じ
た下式の浸入板温Ｔで溶融Ｚｎめっき後、合金化処理を
行うことを特徴とするプレス成形性に優れた合金化溶融
Ｚｎめっき鋼板の製造方法。 （５００Ｐ＋４８０）−２０≦Ｔ≦（５００Ｐ＋４８０
）＋２０但し、Ｔ：浸入板温℃ Ｐ：鋼板中Ｐ含有量ｗｔ％[Claims] C: 0.02wt% or less, Si: 0.1wt% or less, M
n: 0.7wt% or less, P: 0.2wt% or less, N: 0
．． 01 wt% or less, Al: 0.10 wt% or less, Ti alone or Ti and Nb in total of 0.1 wt% or less. After hot-dip Zn plating on the surface of a cold rolled steel sheet, alloying treatment is performed. In the method for producing plated steel sheets, the steel sheets are heated to 700 to 900% in a reducing atmosphere with a H_215% or more and a dew point of +5°C or less without passing through an oxidation furnace or a non-oxidation furnace.
After annealing at a temperature of ℃, hot-dip Zn plating in a hot-dip Zn plating bath containing 0.10 to 0.14 wt% Al at the immersion plate temperature T according to the following formula according to the P content in the steel plate, and then alloying. A method for producing an alloyed hot-dip Zn-plated steel sheet with excellent press formability, the method comprising: processing. (500P+480)-20≦T≦(500P+480
)+20 However, T: Penetration plate temperature °C P: P content wt% in steel plate
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32720389A JP2695260B2 (en) | 1989-12-19 | 1989-12-19 | Method for producing alloyed hot-dip galvanized steel sheet excellent in press formability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32720389A JP2695260B2 (en) | 1989-12-19 | 1989-12-19 | Method for producing alloyed hot-dip galvanized steel sheet excellent in press formability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03191047A true JPH03191047A (en) | 1991-08-21 |
| JP2695260B2 JP2695260B2 (en) | 1997-12-24 |
Family
ID=18196470
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32720389A Expired - Fee Related JP2695260B2 (en) | 1989-12-19 | 1989-12-19 | Method for producing alloyed hot-dip galvanized steel sheet excellent in press formability |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2695260B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05331612A (en) * | 1992-06-01 | 1993-12-14 | Kobe Steel Ltd | Production of galvannealed steel sheet excellent in deep drawability and plating adhesion |
| EP0613961A1 (en) * | 1993-03-04 | 1994-09-07 | Kawasaki Steel Corporation | Alloyed hot dip galvanized steel sheet |
| EP0822267A1 (en) * | 1996-08-01 | 1998-02-04 | Sumitomo Metal Industries, Ltd. | Galvannealed steel sheet and manufacturing method thereof |
| JP2013541645A (en) * | 2010-10-21 | 2013-11-14 | ポスコ | Hot-dip galvanized steel sheet excellent in plating property, plating adhesion and spot weldability, and its production method |
-
1989
- 1989-12-19 JP JP32720389A patent/JP2695260B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05331612A (en) * | 1992-06-01 | 1993-12-14 | Kobe Steel Ltd | Production of galvannealed steel sheet excellent in deep drawability and plating adhesion |
| EP0613961A1 (en) * | 1993-03-04 | 1994-09-07 | Kawasaki Steel Corporation | Alloyed hot dip galvanized steel sheet |
| EP0822267A1 (en) * | 1996-08-01 | 1998-02-04 | Sumitomo Metal Industries, Ltd. | Galvannealed steel sheet and manufacturing method thereof |
| US5897967A (en) * | 1996-08-01 | 1999-04-27 | Sumitomo Metal Industries, Ltd. | Galvannealed steel sheet and manufacturing method thereof |
| JP2013541645A (en) * | 2010-10-21 | 2013-11-14 | ポスコ | Hot-dip galvanized steel sheet excellent in plating property, plating adhesion and spot weldability, and its production method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2695260B2 (en) | 1997-12-24 |
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