JPH04173947A - Method for hot-dip galvanizing high strength steel - Google Patents
Method for hot-dip galvanizing high strength steelInfo
- Publication number
- JPH04173947A JPH04173947A JP30181690A JP30181690A JPH04173947A JP H04173947 A JPH04173947 A JP H04173947A JP 30181690 A JP30181690 A JP 30181690A JP 30181690 A JP30181690 A JP 30181690A JP H04173947 A JPH04173947 A JP H04173947A
- Authority
- JP
- Japan
- Prior art keywords
- plating
- hot
- steel
- cracking
- galvanizing
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 33
- 239000010959 steel Substances 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims description 18
- 238000005246 galvanizing Methods 0.000 title abstract 9
- 229910052718 tin Inorganic materials 0.000 claims abstract description 19
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 7
- 238000007747 plating Methods 0.000 claims description 74
- 239000000463 material Substances 0.000 claims description 28
- 239000012535 impurity Substances 0.000 claims description 2
- 229910052793 cadmium Inorganic materials 0.000 abstract description 19
- 230000007797 corrosion Effects 0.000 abstract description 5
- 238000005260 corrosion Methods 0.000 abstract description 5
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 abstract description 4
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 238000003466 welding Methods 0.000 abstract 3
- 229910001335 Galvanized steel Inorganic materials 0.000 abstract 1
- 239000008397 galvanized steel Substances 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 239000011701 zinc Substances 0.000 description 95
- 238000005336 cracking Methods 0.000 description 37
- 238000012360 testing method Methods 0.000 description 13
- 238000000576 coating method Methods 0.000 description 8
- 239000011248 coating agent Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 229910052725 zinc Inorganic materials 0.000 description 4
- 229910001297 Zn alloy Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000035882 stress Effects 0.000 description 3
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 229910000765 intermetallic Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 235000019270 ammonium chloride Nutrition 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 230000009545 invasion Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 235000005074 zinc chloride Nutrition 0.000 description 1
- 239000011592 zinc chloride Substances 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、送電鉄塔あるいは橋梁などの大型溶接構造物
の防錆に主として用いられる高強度鋼材−の溶融Ｚｎメ
ッキ方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for hot-dip Zn plating of high-strength steel materials mainly used for rust prevention of large welded structures such as power transmission towers or bridges.
鋼材の防錆という観点から、例えばＺｎをメッキする手
段が広（用いられている。Ｚｎをメッキする方法には、
電気メッキによるものと溶融メッキによるものの２種類
がある。複雑な形状の大型溶接構造物は、もっばら後者
の溶融メッキ方法による。この方法は、約４５０ ’Ｃ
の溶融Ｚｎ中に鋼材を浸漬してメッキを行うものである
。From the viewpoint of rust prevention of steel materials, for example, methods of plating Zn are widely used.
There are two types: one by electroplating and one by hot-dip plating. Large welded structures with complex shapes are mostly produced by the latter hot-dip plating method. This method works at approximately 450'C
Plating is performed by immersing the steel material in molten Zn.
溶接構造物の溶融Ｚｎメッキにおいては、主として溶接
熱影響部（以下ＨＡＺと称す）に粒界割れが発生するこ
とがある。これは、粗粒化したＨＡＺの粒界への液体Ｚ
ｎの侵入に、溶接部の残留応力や浴浸漬時に発生する熱
応力が重畳して生じる。このＺｎメッキ割れは、一般に
高強度材はど多く発生する傾向を示し、ＨＡＺ硬さが２
６０〜２７０Ｈｖを超えると極めて感受性が高くなる。In hot-dip Zn plating of welded structures, intergranular cracking may occur mainly in the weld heat affected zone (hereinafter referred to as HAZ). This is due to the liquid Z flowing to the grain boundaries of the coarse-grained HAZ.
Residual stress in the welded portion and thermal stress generated during bath immersion are superimposed on the invasion of n. This Zn plating cracking generally tends to occur more often in high-strength materials, and HAZ hardness is 2.
If it exceeds 60-270 Hv, sensitivity becomes extremely high.
溶接構造物の溶融ＺｎメッキにおけるＺｎメッキ割れに
ついては、その因子である応力と材料の研究は広く行わ
れている。それらの成果に基づき、Ｚｎメッキ割れ防止
法として、溶接部の残留応力除去や、熱応力の少ない浴
浸漬法、構造物の形状などが種々工夫されている。また
、材質面からも、耐Ｚｎメッキ割れ性に優れる鋼材など
が開発されている（例えば特公平２−５８１４号公報）
。With regard to Zn plating cracking in hot-dip Zn plating of welded structures, studies on stress and materials, which are the factors thereof, have been widely conducted. Based on these results, various methods have been devised to prevent Zn plating from cracking, such as removing residual stress from welds, bath immersion with less thermal stress, and the shape of structures. In addition, from the material standpoint, steel materials with excellent Zn plating cracking resistance have been developed (for example, Japanese Patent Publication No. 2-5814).
.
しかし、Ｚｎメッキ割れには、上記因子だけでなくメッ
キに用いられる熔融Ｚｎの性質も大きく影響していると
考えられる。それにもかかわらず、熔融Ｚｎに注目した
Ｚｎメッキ割れの研究は少ない。僅かに文献「高温学会
誌、４ ＶｏＣ１３，に４ （１９８７）ＰＬ４３〜１
５２に、溶融ＺｎとＺｎメッキ割れとの関係に触れた報
告が見られる程度であり、溶融Ｚｎの観点からの積極的
なＺｎメッキ割れ防止法は皆無といえる。However, cracks in Zn plating are thought to be greatly influenced not only by the above factors but also by the properties of molten Zn used for plating. Despite this, there are few studies on Zn plating cracking that have focused on molten Zn. There are only a few references: Journal of the Society of High Temperature Science, 4 VoC13, 4 (1987) PL43-1
No. 52, there is only a report that mentions the relationship between molten Zn and Zn plating cracking, and it can be said that there is no active method for preventing Zn plating cracking from the perspective of molten Zn.
上記文献によると、溶融Ｚｎ中に含まれるＣｄやＳｎが
、粒界へのＺｎの侵入を加速するとされており、Ｚｎメ
ンキ割れ感受性がＣｄやＳｎによって高くなり、Ｃｄや
Ｓｎを含まない純Ｚｎ中でＺｎメッキ割れ感受性が最も
低いことが示されている。また、ＣｄやＳｎのこのよう
な効果は、溶融Ｚｎメッキ時に形成されるＦｅ−Ｚｎ金
属間化合物の生成と関係があると考察されている。簡単
に言えば、溶融Ｚｎ中のＣｄやＳｎが綱とＺｎ浴の界面
に形成されるＦｅ−Ｚｎ金属間化合物の成長を抑制する
ので、溶融ＺｎＯ綱粒界への侵入が加速され、結果とし
てＺｎメッキ割れ感受性が高くなるというものである。According to the above literature, it is said that Cd and Sn contained in molten Zn accelerate the penetration of Zn into grain boundaries, and that Cd and Sn increase Zn cracking susceptibility, and that pure Zn containing no Cd and Sn increases Zn cracking susceptibility. It has been shown that Zn plating cracking sensitivity is the lowest among them. It is also considered that such effects of Cd and Sn are related to the generation of Fe-Zn intermetallic compounds formed during hot-dip Zn plating. Simply put, Cd and Sn in molten Zn suppress the growth of Fe-Zn intermetallic compounds formed at the interface between the wire and the Zn bath, accelerating their penetration into the molten ZnO wire grain boundaries, and as a result. This increases the Zn plating susceptibility to cracking.
なお、ＣｄやＳｎの含有量の少ない純Ｚｎは電解法によ
って得ることができる。これは、工業的に利用可能であ
るが、溶融Ｚｎメンキに通常使用される蒸留Ｚｎに比し
て高価である。Note that pure Zn with a low content of Cd and Sn can be obtained by an electrolytic method. Although it is commercially available, it is more expensive than distilled Zn, which is commonly used for molten Zn coatings.
〔発明が解決しようとする課題］
ところで、従来開発されている耐Ｚｎメッキ割れに優れ
た鋼材は、いずれも強度６０ｋｇ／ｍｍｚ級までである
。しかし、最近は溶接構造物の大型化、鋼材使用量低減
による低コスト化が著しく進み、強度６５ｋｇ／ｍ＋”
吸収上の鋼材も望まれている。[Problems to be Solved by the Invention] By the way, conventionally developed steel materials with excellent Zn plating cracking resistance all have a strength of up to 60 kg/mmz class. However, recently, welded structures have become larger and costs have been significantly reduced by reducing the amount of steel used, and the strength has increased to 65 kg/m+.
Absorbent steel materials are also desired.
ところが、Ｚｎメッキ割れ感受性は、前述した通り高強
度鋼材はど高くなる。However, as mentioned above, the susceptibility to Zn plating cracking increases with high-strength steel materials.
一方、構造物の溶融Ｚｎメッキでは、耐Ｚｎメ、キ割れ
性以外に、Ｚｎメッキの密着性も等しく重要視される。On the other hand, in hot-dip Zn plating of structures, in addition to Zn resistance and cracking properties, adhesion of Zn plating is equally important.
というのは、部分的にしろＺｎメッキが剥離すると、そ
の箇所はＺｎメ、キによる耐食性改善効果がほとんどな
く、棟材と同様の腐食速度になり、それで構造物の耐用
年数が決まってしまうからである。従って、構造物の溶
融Ｚｎメッキでは、Ｚｎメンキ割れの有無の検査以外に
、ハンマーテストなどでＺｎメッキの密着性が必ず検査
される。This is because if the Zn plating peels off, even if it is only partially, the Zn coating will have little effect on improving corrosion resistance in that area, and the corrosion rate will be the same as that of the ridge material, which will determine the service life of the structure. It is. Therefore, when hot-dip Zn plating a structure, in addition to inspecting the presence or absence of cracks in the Zn coating, the adhesion of the Zn plating is always inspected by a hammer test or the like.
しかし、そのような事情があるにもががわらず、耐Ｚｎ
メンキ割れとＺｎメンキの密着性との関係について触れ
た報告も、本発明者らの知る限り存在しない。前記文献
によっても、Ｚｎメッキ割れに関係しているＺｎ浴中の
ＣｄやＳｎが、Ｚｎメッキ密着性とどのように関係して
いるかは不明である。However, despite such circumstances, Zn-resistant
As far as the present inventors are aware, there is no report that mentions the relationship between coating cracking and Zn coating adhesion. Even from the above literature, it is unclear how Cd and Sn in the Zn bath, which are related to Zn plating cracking, are related to Zn plating adhesion.
ところが、この点に関し、注目すべき事実が本発明者ら
の研究から明らかになった。それは、Ｚｎメッキ割れの
重要因子であるＺｎ浴中のＣｄやＳｎが、一方でＺｎメ
ッキの密着性の改善に寄与するというものである。強度
６５ｋｇ／閣２級のようなＺｎメッキ割れの発生しゃす
い高強度鋼材に対しては、Ｚｎ浴中からＣｄやＳｎを極
力排除することが必要になるが、これはＺｎメッキの密
着性を確保する点から言えば逆効果になる。鋼材の高強
度化が推進されている大型溶接構造物で、このことが大
きな問題になることは言うまでもない。However, in this regard, a noteworthy fact has become clear through research conducted by the present inventors. This is because Cd and Sn in the Zn bath, which are important factors in Zn plating cracking, also contribute to improving the adhesion of Zn plating. For high-strength steel materials with a strength of 65 kg/Kaku 2, which are susceptible to Zn plating cracking, it is necessary to exclude Cd and Sn from the Zn bath as much as possible, but this reduces the adhesion of the Zn plating. From the point of view of ensuring security, it will have the opposite effect. Needless to say, this becomes a major problem in large welded structures where steel materials are being made to have higher strength.
本発明の目的は、強度６５ｋｇ／ａｍ”級の高強度材に
も優れた耐Ｚｎメッキ割れ性を付与し、しがもＺｎメン
キの密着性を低下させるおそれがない高強度鋼材の溶融
Ｚｎメッキ方法を提供することにある。The purpose of the present invention is to impart excellent Zn plating cracking resistance even to high-strength materials with a strength of 65 kg/am" class, and to provide hot-dip Zn plating for high-strength steel materials without the risk of reducing the adhesion of Zn coatings. The purpose is to provide a method.
前述した通り、耐Ｚｎメッキ割れ性とＺｎノットの密着
性とは、相反するものであることが本発明者らの研究か
ら明らかになった。即ち、耐メ。As mentioned above, it has become clear from research by the present inventors that Zn plating cracking resistance and Zn knot adhesion are contradictory. In other words, resistance.
キ割れ性に優れる溶融Ｚｎではメッキの密着性が低下し
、密着性がよい溶融Ｚｎでは割れ感受性が高まる。Molten Zn, which has excellent cracking properties, reduces plating adhesion, and molten Zn, which has good adhesion, increases cracking susceptibility.
例えば、純Ｚｎ中では、Ｆｅ−Ｚｎ合金メッキが厚く生
成するので、後述の実施例に示すようなメッキ割れ性試
験でメッキ割れを生じないが、その反面Ｆｅ−Ｚｎ合金
メンキ相が硬くて脆く、メッキ相中に容易に割れを生し
剥離が起こった。−方、ＣｄとＳｎをそれぞれ０．１
ｗ ｔ％ずっ含む蒸留Ｚｎ浴中では、Ｆｅ−Ｚｎ合金メ
ッキ相の生成が抑えられ、Ｚｎメッキの密着性は良好な
ものの、メッキ割れ性試験で）ＩＡＺにメッキ割れが生
じた。For example, in pure Zn, Fe-Zn alloy plating is formed thickly, so no plating cracks occur in the plating crackability test shown in the examples below, but on the other hand, the Fe-Zn alloy coating phase is hard and brittle. , cracks easily formed in the plating phase and peeling occurred. - On the other hand, Cd and Sn are each 0.1
In a distilled Zn bath containing 50% by weight, the formation of the Fe-Zn alloy plating phase was suppressed and the adhesion of the Zn plating was good, but plating cracking occurred on IAZ (in the plating cracking test).
また、熱延あるいは冷延コイルの溶融Ｚｎメッキでは、
Ｚｎメッキの付着量の制御に使用されるＡｌが、Ｃｄと
Ｓｎと同様の作用を示し、且つ少ない量でも、その作用
の大きいことが明らかになった。In addition, in hot-dip Zn plating of hot-rolled or cold-rolled coils,
It has become clear that Al, which is used to control the amount of Zn plating, exhibits the same effect as Cd and Sn, and that even a small amount has a large effect.
本発明者らは、このような知見事実を背景として、耐Ｚ
ｎメッキ割れ性とＺｎメッキの密着性との両立法につい
て鋭意検討した。その結果、Ｚｎメッキの密着性を劣化
させず、且つ強度６５ｋｇ／ｍ”級の高強度材にもＺｎ
メッキ割れを起こさせない適正な量的範囲が、Ｃｄ、Ｓ
ｎ及びＡｌに存在することが判明した。Based on these findings, the present inventors have developed a Z-resistant
A method for achieving both N plating crackability and Zn plating adhesion was intensively studied. As a result, the adhesion of Zn plating does not deteriorate, and Zn can be applied to high-strength materials with a strength of 65 kg/m" class.
The appropriate quantitative range that does not cause plating cracking is Cd, S.
It was found that it exists in n and Al.
本発明は、Ｃｄ：Ｏ，１０ｗｔ％以下、Ｓｎ：０゜１０
ｗｔ％以下、Ａｆ：０．０５ｗｔ％以下を含み、かつ、
０．０５ｗｔ％≦Ｃｄ＋Ｓｎ＋Ａ／！≦０．１５ｗｔ％
を満足し、残部Ｚｎ及び不可避不純物からなる溶融Ｚｎ
浴に、高強度鋼材を浸漬してメッキすることを特徴とす
る高強度鋼材の溶融Ｚｎメッキ方法を要旨とする。In the present invention, Cd: O, 10 wt% or less, Sn: 0°10
wt% or less, Af: 0.05wt% or less, and
0.05wt%≦Cd+Sn+A/! ≦0.15wt%
Molten Zn that satisfies the following and consists of the remainder Zn and unavoidable impurities
The gist of this invention is a method for hot-dip Zn plating of high-strength steel materials, which is characterized by plating the high-strength steel materials by immersing them in a bath.
〔作 用）
本発明の溶融Ｚｎメッキ方法は、Ｚｎメッキ割れ感受性
が大きい強度５．５ｋｇ／ｍ”以上の高強度鋼材を対象
とし、特に強度６５ｋｇ／ｍｍ”以上のものに対して効
果的である。強度６５ｋｇ／ｍ＋２以上の高強度鋼材で
は、従来有効なＺｎメッキ割れ防止法がなく、且っＺｎ
メッキ密着性との両立がとりわけ難しい。[Function] The hot-dip Zn plating method of the present invention targets high-strength steel materials with a strength of 5.5 kg/m" or more and is particularly effective for steel materials with a strength of 65 kg/m" or more, which are highly susceptible to Zn plating cracking. be. For high-strength steel materials with a strength of 65 kg/m+2 or more, there is no effective method to prevent cracking of Zn plating, and
It is particularly difficult to balance this with plating adhesion.
なお、Ｚｎメッキ割れ感受性は鋼材強度が低くなるほど
低下するが、Ｚｎメッキの密着性は材料強度に依存しな
い。従って、主にＺｎメッキ密着性の改善のために本発
明法を低強度鋼に適用することは可能である。Note that although the Zn plating cracking susceptibility decreases as the steel material strength decreases, the adhesion of Zn plating does not depend on the material strength. Therefore, it is possible to apply the method of the present invention to low-strength steel mainly for improving Zn plating adhesion.
溶融Ｚｎ浴中のＣｄ、Ｚｎ及びＡｌ量については、耐メ
・７キ割れ性を確保するために各量を制限する一方、Ｚ
ｎメッキの密着性低下を阻止するために総量の確保を行
う。この観点から、Ｃｄは０゜１０ｗｔ％以下とし、こ
れを超えるとＺｎメッキ割れ感受性が高くなる。望まし
くは０．０８ｗｔ％以下である。Ｓｎも０．１０ ｗ
ｔ％以下とし、これを超えるとＺｎメッキ割れ感受性が
高くなる。望ましくは０．０８ｗｔ％以下である。Ａｌ
２はＣｄ。Regarding the amounts of Cd, Zn, and Al in the molten Zn bath, each amount is limited to ensure metal cracking resistance.
The total amount is secured to prevent the adhesion of n plating from decreasing. From this point of view, the Cd content should be 0°10 wt% or less, and if it exceeds this, the Zn plating will be susceptible to cracking. It is preferably 0.08 wt% or less. Sn is also 0.10w
t% or less; if it exceeds this, the Zn plating becomes susceptible to cracking. It is preferably 0.08 wt% or less. Al
2 is Cd.
Ｓｎよりも過敏で、０．０５ｗｔ％以下とする。０゜０
５ｗｔ％を超えると、Ｚｎメッキ割れ感受性が高くなり
、望ましくは０．０４％以下である。Ｃｄ＋Ｓｎ十Ａ！
については、０．０５ｗｔ％以上、０゜１５ｗｔ％以下
とする。０．０５ｗｔ％未満ではＺｎメッキの密着性が
低下し、０．１５ ｗ ｔ％超ではＺｎメッキ割れ感受
性が高くなる。このようなＣｄ、Ｓｎ、Ａｌ量の制御は
、例えば蒸留Ｚｎ浴に、電解法で得た純Ｚｎを適量混合
することによって可能である。It is more sensitive than Sn and should be 0.05 wt% or less. 0゜0
When the content exceeds 5 wt%, the Zn plating susceptibility to cracking becomes high, and the content is desirably 0.04% or less. Cd+Sn10A!
The content shall be 0.05 wt% or more and 0°15 wt% or less. If it is less than 0.05 wt%, the adhesion of Zn plating will decrease, and if it exceeds 0.15 wt%, the Zn plating will be susceptible to cracking. Such control of the amounts of Cd, Sn, and Al can be achieved, for example, by mixing an appropriate amount of pure Zn obtained by an electrolytic method into a distilled Zn bath.
第１表に示す組成を有する綱を熱間圧延して板厚１５■
の強度６５ｋｇ／■２級高強度鋼板とした。A steel having the composition shown in Table 1 is hot-rolled to a thickness of 15 cm.
The steel plate was made of grade 2 high-strength steel plate with a strength of 65 kg/■.
第 １ 表（ｗｔ％）
この鋼板から第１図に示すような拘束継手を多数製作し
た。製作された各継手を、塩化アンモニウムと塩化亜鉛
を３＝１で混合した５０°Ｃの水溶液に約１０分間浸漬
するフラックス処理で前処理した後、第２表に示す各種
組成を有する４５０°ＣのＺｎ浴に１０分間浸漬した。Table 1 (wt%) A large number of restraint joints as shown in FIG. 1 were manufactured from this steel plate. Each of the manufactured joints was pretreated with flux treatment by immersing them in an aqueous solution of ammonium chloride and zinc chloride mixed in a ratio of 3=1 at 50°C for about 10 minutes, and then fluxed at 450°C with various compositions shown in Table 2. It was immersed in a Zn bath for 10 minutes.
浴中から取り出した後は空冷をした。試験ビード部を１
０等分して、その断面を検査して割れの有無を調査した
。調査数Ｎは各浴につき２とした。After taking it out of the bath, it was air cooled. Test bead part 1
It was divided into 0 equal parts and the cross section was inspected to check for cracks. The number N of investigations was 2 for each bath.
マタ、ＪＩＳＨＯ４０１に規定されるハンマ試験でＺｎ
メッキの密着性を調べた。即ち、継手試験に用いたのと
同一の鋼材から１０Ｘ１０ｃ＋ｍの試験板を切り出し、
同様のフラックス処理を施し、４５０ ’Ｃの各Ｚｎ浴
に１０分間浸漬した。その後、第２図に示す試験装置を
用いて試験板のメッキ部分をハンマでそれぞれ３０点た
たいてみて、欠点数３以上のメンキが剥離し易いものを
密着性不良（×）、３未満の剥離し難いものを密着性良
好（０）と判断した。Mata, Zn in the hammer test specified in JISHO401
The adhesion of plating was investigated. That is, a 10x10c+m test plate was cut out from the same steel material used for the joint test,
A similar flux treatment was performed and immersed in each Zn bath at 450'C for 10 minutes. Then, using the testing device shown in Figure 2, the plated parts of the test plate were struck at 30 points each with a hammer, and those with 3 or more defects where the coating easily peeled off were marked as poor adhesion (x), and those with less than 3 defects were marked with poor adhesion (x). Those that were difficult to peel off were judged to have good adhesion (0).
これらの試験結果を第２表に示す。The results of these tests are shown in Table 2.
第 ２ 表（１）
第 ２ 表（２）
比較例１〜６は、Ｃｄ、Ｓｎ、Ａｊ！の各量が少ないの
で密着性に劣る。本発明例７〜１７は、Ｃｄ、Ｓｎ、Ａ
ｌの各量及び総量が適正範囲にあるので、密着性及び耐
Ｚｎメッキ割れ性のいずれにも優れる。比較例１８〜２
３は、Ｃｄ、Ｓｎ、Ａｌの総量が０．１５％を超えるの
で耐Ｚｎメッキ割れ性に劣る。比較例２４〜２７は、Ｃ
ｄ、Ｓｎ、ＡＮの各量が適正値を超えるので耐Ｚｎメ、
キ割れ性に劣る。Table 2 (1) Table 2 (2) Comparative Examples 1 to 6 are Cd, Sn, Aj! Since the amount of each is small, the adhesion is poor. Examples 7 to 17 of the present invention are Cd, Sn, A
Since each amount and the total amount of 1 are within appropriate ranges, both adhesion and Zn plating cracking resistance are excellent. Comparative examples 18-2
Sample No. 3 has poor Zn plating cracking resistance because the total amount of Cd, Sn, and Al exceeds 0.15%. Comparative Examples 24 to 27 are C
Since each amount of d, Sn, and AN exceeds the appropriate value, Zn resistance method,
Poor cracking resistance.
（発明の効果〕
本発明の高強度鋼材の溶融Ｚｎメッキ方法は、Ｚｎメッ
キ感受性の高い強度６５ｋｇ／Ｉ１１”級鋼材にもメッ
キ割れを発生させず、且つ優れたＺｎメッキ密着性を確
保する。従って、大型溶接構造物の耐食性が改善され、
使用鋼材の高強度化による溶接構造物の高強度化、軽量
化も可能になる。(Effects of the Invention) The hot-dip Zn plating method for high-strength steel materials of the present invention does not cause plating cracks even on 65 kg/I11'' class steel materials that are highly sensitive to Zn plating, and ensures excellent Zn plating adhesion. Therefore, the corrosion resistance of large welded structures is improved,
By increasing the strength of the steel used, it becomes possible to increase the strength and reduce the weight of welded structures.
第１図は拘束継手試験体の構造を示す模式図、第２図は
ハンマ試験に用いたハンマ試験装置の模式図である。FIG. 1 is a schematic diagram showing the structure of the restrained joint test specimen, and FIG. 2 is a schematic diagram of the hammer test device used in the hammer test.
Claims (1)
％以下、Ａｌ：０．０５ｗｔ％以下を含み、かつ、０．
０５ｗｔ％≦Ｃｄ＋Ｓｎ＋Ａｌ≦０．１５ｗｔ％を満足
し、残部Ｚｎ及び不可避不純物からなる溶融Ｚｎ浴に、
高強度鋼材を浸漬してメッキすることを特徴とする高強
度鋼材の溶融Ｚｎメッキ方法。(1) Cd: 0.10wt% or less, Sn: 0.10wt
% or less, Al: 0.05 wt% or less, and 0.05 wt% or less.
In a molten Zn bath satisfying 0.5wt%≦Cd+Sn+Al≦0.15wt% and consisting of the balance Zn and unavoidable impurities,
A method for hot-dip Zn plating of high-strength steel materials, characterized by immersing and plating the high-strength steel materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30181690A JPH04173947A (en) | 1990-11-06 | 1990-11-06 | Method for hot-dip galvanizing high strength steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30181690A JPH04173947A (en) | 1990-11-06 | 1990-11-06 | Method for hot-dip galvanizing high strength steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04173947A true JPH04173947A (en) | 1992-06-22 |
Family
ID=17901508
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30181690A Pending JPH04173947A (en) | 1990-11-06 | 1990-11-06 | Method for hot-dip galvanizing high strength steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04173947A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010070851A (en) * | 2008-08-21 | 2010-04-02 | Kawada Kogyo Kk | Hot-dip galvanized member superior in coatability by thermal spraying |
-
1990
- 1990-11-06 JP JP30181690A patent/JPH04173947A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010070851A (en) * | 2008-08-21 | 2010-04-02 | Kawada Kogyo Kk | Hot-dip galvanized member superior in coatability by thermal spraying |
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