JP2011191270A - Method for evaluating corrosion resistance of magnesium alloy material - Google Patents
Method for evaluating corrosion resistance of magnesium alloy material Download PDFInfo
- Publication number
- JP2011191270A JP2011191270A JP2010059761A JP2010059761A JP2011191270A JP 2011191270 A JP2011191270 A JP 2011191270A JP 2010059761 A JP2010059761 A JP 2010059761A JP 2010059761 A JP2010059761 A JP 2010059761A JP 2011191270 A JP2011191270 A JP 2011191270A
- Authority
- JP
- Japan
- Prior art keywords
- corrosion
- treatment
- magnesium alloy
- resistance
- alloy material
- 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
Landscapes
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
Description
本発明は、マグネシウム合金材の耐食性の評価に利用されるマグネシウム合金材の耐食性の評価方法に関するものである。特に、短時間で耐食性を調べられるマグネシウム合金材の評価方法に関するものである。 The present invention relates to a method for evaluating the corrosion resistance of a magnesium alloy material used for evaluating the corrosion resistance of a magnesium alloy material. In particular, the present invention relates to a method for evaluating a magnesium alloy material whose corrosion resistance can be examined in a short time.
マグネシウムに種々の添加元素を含有したマグネシウム合金が、携帯電話やノート型パーソナルコンピュータといった携帯用電気・電子機器類の筐体や自動車部品などの各種の部材の構成材料に利用されてきている。 Magnesium alloys containing various additive elements in magnesium have been used as constituent materials for various members such as casings of portable electric and electronic devices such as mobile phones and notebook personal computers and automobile parts.
マグネシウム合金からなる部材は、ダイカスト法やチクソモールド法による鋳造材(ASTM規格のAZ91合金)が主流である。近年、ASTM規格のAZ31合金に代表される展伸用マグネシウム合金からなる板にプレス加工を施した部材が使用されつつある。特許文献1には、ASTM規格におけるAZ91合金相当の合金からなる圧延材にプレス加工を施した後、化成処理及び塗装処理を施したマグネシウム合金部材が開示されている。 As for the members made of magnesium alloy, casting materials (ASTM standard AZ91 alloy) by die casting method or thixo mold method are mainly used. In recent years, a member obtained by pressing a plate made of a magnesium alloy for extension represented by ASTM standard AZ31 alloy is being used. Patent Document 1 discloses a magnesium alloy member obtained by subjecting a rolled material made of an alloy equivalent to the AZ91 alloy in the ASTM standard to press processing, and then performing chemical conversion treatment and coating treatment.
マグネシウムは、活性な金属であるため、上述のようにマグネシウム合金部材の表面には、通常、陽極酸化処理や化成処理といった防食処理が施される。そして、JISに規格される塩水噴霧試験(非特許文献1)といった腐食を進行するための処理(以下、腐食進行処理と呼ぶ)が行われて、耐食性が評価される(特許文献1の明細書0027など)。JIS Z 2371(2000)の塩水噴霧試験では、腐食状態の評価を目視確認やレイティングナンバ法により行うことを規定している。 Since magnesium is an active metal, the surface of the magnesium alloy member is usually subjected to anticorrosion treatment such as anodizing treatment or chemical conversion treatment as described above. Then, a treatment for advancing corrosion such as a salt spray test (Non-patent Document 1) specified by JIS is performed (hereinafter referred to as a corrosion proceeding process), and the corrosion resistance is evaluated (the specification of Patent Document 1). 0027). The salt spray test of JIS Z 2371 (2000) stipulates that the corrosion state is evaluated by visual confirmation or the rating number method.
しかし、従来の耐食性の評価方法では、以下の(1)〜(3)の問題がある。 However, the conventional methods for evaluating corrosion resistance have the following problems (1) to (3).
(1) 試験時間が長い。
評価方法が目視確認であるため、腐食進行処理の処理時間が短いと、微小な変化を捉えることが難しい。このことから、耐食性を十分に把握するために、腐食を著しく進行させる必要があり、処理時間(試験時間)が長くなる(一般に100時間程度)。
(1) The test time is long.
Since the evaluation method is visual confirmation, it is difficult to capture minute changes when the processing time of the corrosion progress processing is short. For this reason, in order to sufficiently grasp the corrosion resistance, it is necessary to remarkably advance the corrosion, and the processing time (test time) becomes long (generally about 100 hours).
(2) 定量的な情報を得ることが難しい。
目視による主観的な評価(定性的評価)やレイティングナンバ法による評価では、検査者によるばらつきがあり、微小な差異を定量的に把握することができない。
(2) It is difficult to obtain quantitative information.
In subjective evaluation by visual inspection (qualitative evaluation) and evaluation by the rating number method, there are variations among inspectors, and minute differences cannot be grasped quantitatively.
(3) 腐食減量を利用すると、[1]測定自体が煩雑で時間がかかる、[2]環境負荷が高い、[3]測定精度が低い。
定量的な評価を行うにあたり、目視確認などではなく、腐食減量を測定することが考えられる。しかし、腐食減量を測定するためには、腐食進行処理を施した試験片から腐食生成物を除去する必要があり、この除去処理が煩雑であることから、結果として評価に要する時間が長くなる。また、腐食生成物の除去には、有害物質(代表的にはクロム酸)を含む液体を用いるため、環境への負荷が高い。更に、一般に、腐食減量を測定する場合、試料の一部のみを試験部位(腐食部位)とするため、腐食減量が微小であることからS/N比が低く、精度良く調べられないことがある。また、腐食の状態によっては、腐食生成物を十分に除去できず、精度良く調べられないことがある。
(3) Using corrosion weight loss, [1] measurement itself is complicated and time consuming, [2] environmental load is high, [3] measurement accuracy is low.
In performing quantitative evaluation, it is conceivable to measure corrosion weight loss rather than visual confirmation. However, in order to measure the corrosion weight loss, it is necessary to remove the corrosion products from the test piece subjected to the corrosion progress treatment, and this removal treatment is complicated, resulting in a longer time for evaluation. Moreover, since the liquid containing a harmful substance (typically chromic acid) is used to remove the corrosion products, the burden on the environment is high. Furthermore, in general, when measuring the weight loss of corrosion, since only a part of the sample is used as a test site (corrosion site), the S / N ratio is low due to the fact that the weight loss of corrosion is very small, and it may not be possible to investigate accurately . In addition, depending on the state of corrosion, the corrosion product may not be sufficiently removed and may not be examined with high accuracy.
上記の問題は、塩水噴霧試験だけでなく、各種の暴露試験や塩水浸漬試験を腐食の評価に利用した場合にも生じ得る。 The above problems can occur not only in the salt spray test but also when various exposure tests and salt water immersion tests are used for corrosion evaluation.
従って、マグネシウム合金材に対して、短時間で精度良く、かつ定量的に耐食性を評価することができる評価方法の開発が望まれる。 Therefore, it is desired to develop an evaluation method that can accurately and quantitatively evaluate corrosion resistance in a short time with respect to a magnesium alloy material.
そこで、本発明の目的は、短時間で耐食性を定量的に評価することができるマグネシウム合金材の耐食性の評価方法を提供することにある。 Then, the objective of this invention is providing the corrosion resistance evaluation method of the magnesium alloy material which can evaluate corrosion resistance quantitatively in a short time.
本発明者らは、マグネシウム合金材を対象に塩水噴霧や塩水浸漬といった腐食進行処理を行って、耐食性を定量的に調べるにあたり、種々の手法を検討した。その結果、交流インピーダンス法による腐食反応抵抗の測定といった電気化学測定を利用すると、目視では耐食性の差異が認められない程度の腐食状態であっても、短時間で、かつ精度良く定量的に耐食性の優劣を評価できる、との知見を得た。本発明は、上記知見に基づくものである。 The present inventors examined various methods for quantitatively examining the corrosion resistance by subjecting the magnesium alloy material to corrosion progress treatment such as salt spray and salt water immersion. As a result, when using electrochemical measurements such as the measurement of corrosion reaction resistance by the AC impedance method, even in a corrosion state where visual differences in corrosion resistance are not recognized, corrosion resistance can be quantitatively measured accurately in a short time. The knowledge that superiority and inferiority can be evaluated was obtained. The present invention is based on the above findings.
本発明は、マグネシウム合金材の耐食性を評価するマグシウム合金材の耐食性の評価方法である。具体的には、上記マグネシウム合金材に腐食進行処理を行い、上記腐食進行処理が施されたマグネシウム合金材に対して交流インピーダンス法により腐食反応抵抗を測定する。そして、この測定値と、上記腐食進行処理前におけるマグネシウム合金材の腐食反応抵抗値との大小を比較することで、耐食性を評価する。 The present invention is a method for evaluating the corrosion resistance of a magnesium alloy material for evaluating the corrosion resistance of a magnesium alloy material. Specifically, the magnesium alloy material is subjected to a corrosion progress treatment, and the corrosion reaction resistance is measured by an alternating current impedance method for the magnesium alloy material subjected to the corrosion progress treatment. And corrosion resistance is evaluated by comparing the magnitude of this measured value with the corrosion reaction resistance value of the magnesium alloy material before the above-mentioned corrosion progress treatment.
従来、鋼などの金属部材に対して、交流インピーダンス法により腐食反応抵抗を測定することは行われていた。但し、この測定は、上記金属部材が塩水噴霧などの腐食進行処理が施されていない状態で行われ、このときの測定値(絶対値)が大きい場合、通常、測定対象は、耐食性が高いと評価されていた。一方、上記腐食進行処理が施された試料は、腐食が進行していることが明らかであり、従来、上記腐食進行処理の後に上記腐食反応抵抗を測定することは無かった。しかし、本発明者らが調べたところ、上記腐食進行処理後に上記腐食反応抵抗値を測定し、当該測定値と上記腐食進行処理の前の測定値(以下、初期値と呼ぶ)とを比較すると、マグネシウム合金材において耐食性に優れるものと、耐食性に劣るものとでは、上記処理前後の測定値の変化度合いが異なっていた。また、上記腐食進行処理が5分や10分といった極短時間であり、通常、目視では耐食性の差異が実質的に認められない程度の腐食状態であっても、マグネシウム合金材において耐食性に優れるものと、耐食性に劣るものとでは、上記処理前後の測定値の変化度合いが異なっていた。以上から、本発明では、マグネシウム合金材の耐食性の評価方法として、上記腐食進行処理前後の腐食反応抵抗の大小を比較することを提案する。 Conventionally, a corrosion reaction resistance has been measured for a metal member such as steel by an AC impedance method. However, this measurement is performed in a state where the metal member has not been subjected to corrosion progress treatment such as salt spray, and when the measured value (absolute value) at this time is large, the measurement object is usually high in corrosion resistance. It was evaluated. On the other hand, it is clear that the sample subjected to the corrosion progress treatment is progressing in corrosion, and conventionally, the corrosion reaction resistance has not been measured after the corrosion progress treatment. However, as a result of investigation by the present inventors, the corrosion reaction resistance value is measured after the corrosion progression treatment, and the measured value and the measurement value before the corrosion progression treatment (hereinafter referred to as initial values) are compared. In the magnesium alloy material, the degree of change in the measured value before and after the treatment was different between the one having excellent corrosion resistance and the one having poor corrosion resistance. In addition, the above-mentioned corrosion progression treatment is extremely short, such as 5 minutes or 10 minutes, and usually has excellent corrosion resistance in magnesium alloy materials even in a corrosion state where there is virtually no difference in corrosion resistance visually. And the degree of change in the measured values before and after the treatment was different from that having poor corrosion resistance. From the above, in the present invention, as a method for evaluating the corrosion resistance of a magnesium alloy material, it is proposed to compare the magnitude of the corrosion reaction resistance before and after the above-described corrosion progress treatment.
上記構成によれば、腐食進行処理の前後において、交流インピーダンス法により腐食反応抵抗を測定し、その大小を調べるだけで、簡単にかつ短時間に、そして定量的に精度良く耐食性を評価することができる。 According to the above configuration, the corrosion resistance can be evaluated easily and in a short time and quantitatively with high accuracy simply by measuring the corrosion reaction resistance by the AC impedance method before and after the corrosion progress treatment and examining the magnitude. it can.
本発明の評価方法の対象となるマグネシウム合金材の形態は、特に問わない。例えば、鋳造材、鋳造材に溶体化処理などの熱処理を施した熱処理材、鋳造材や上記熱処理材に圧延を施した圧延材、圧延材に歪取りを主目的とするアニールといった熱処理を施したアニール材、上記圧延材やアニール材に矯正を施した矯正材、上記圧延材やアニール材、矯正材にプレス加工といった塑性加工を施した塑性加工材、などが挙げられる。 The form of the magnesium alloy material that is the subject of the evaluation method of the present invention is not particularly limited. For example, a cast material, a heat treatment material obtained by subjecting the cast material to a heat treatment such as a solution treatment, a rolled material obtained by rolling the cast material or the heat treatment material, and a heat treatment such as annealing for mainly removing strain are applied to the rolled material. Examples thereof include an annealed material, a straightened material obtained by correcting the rolled material and the annealed material, a rolled material, an annealed material, a plastic processed material obtained by subjecting the straightened material to plastic working such as press working, and the like.
上記マグネシウム合金材を構成するマグネシウム合金の組成も特に問わない。代表的には、マグネシウム合金は、例えば、Al,Zn,Mn,Si,Ca,Sr,Y,Cu,Ag,Sn,Li,Zr及び希土類元素(Yを除く)から選択される少なくとも1種の元素を合計で0.01質量％以上20質量％以下含有し、残部がMg及び不純物からなるものが挙げられる。特に、Alを含有するマグネシウム合金として、例えば、ASTM規格におけるAZ系合金(Mg-Al-Zn系合金、Zn:0.2質量％〜1.5質量％)、AM系合金(Mg-Al-Mn系合金、Mn:0.15質量％〜0.5質量％)、AS系合金(Mg-Al-Si系合金、Si:0.6質量％〜1.4質量％)、Mg-Al-RE(希土類元素)系合金、AX系合金（Mg-Al-Ca系合金、Ca:0.2質量％〜6.0質量％）、AJ系合金(Mg-Al-Sr系合金、Sr:0.2質量％〜7.0質量％)が挙げられる。 The composition of the magnesium alloy constituting the magnesium alloy material is not particularly limited. Typically, the magnesium alloy is, for example, at least one selected from Al, Zn, Mn, Si, Ca, Sr, Y, Cu, Ag, Sn, Li, Zr and rare earth elements (excluding Y). A total of 0.01% by mass or more and 20% by mass or less of elements, with the balance being Mg and impurities. In particular, as a magnesium alloy containing Al, for example, an AZ-based alloy (Mg-Al-Zn-based alloy, Zn: 0.2 mass% to 1.5 mass%) in the ASTM standard, an AM-based alloy (Mg-Al-Mn-based alloy, Mn: 0.15 mass% to 0.5 mass%), AS alloy (Mg-Al-Si alloy, Si: 0.6 mass% to 1.4 mass%), Mg-Al-RE (rare earth element) alloy, AX alloy ( Mg-Al-Ca alloy, Ca: 0.2 mass% to 6.0 mass%), and AJ alloy (Mg-Al-Sr alloy, Sr: 0.2 mass% to 7.0 mass%).
上記腐食進行処理は、代表的には、JIS Z 2371(2000)に規定される塩水噴霧試験に準じた塩水噴霧が挙げられる。その他、塩水浸漬、各種の暴露試験(例えば、JIS Z 2381(2001) 大気暴露試験方法通則の表1に記載される暴露試験方法)に準じた暴露処理を利用することができ、特に問わない。上記腐食進行処理に利用する腐食液の組成や試験環境(温度、湿度など)も適宜選択することができる。また、上記腐食進行処理の時間も、適宜選択することができる。例えば、従来のように100時間程度と長くすることもできるが、最終的な評価までの時間の増大を招くことから好ましくない。特に、24時間以下、更に3時間以下、とりわけ30分以下であると、最終的な評価までの時間が短く、実用に適していると期待される。後述する試験例に示すように、5分程度、試験片の組成などによっては1分程度でも耐食性の評価を十分に行えると期待される。 A typical example of the corrosion progression treatment is salt spray in accordance with a salt spray test defined in JIS Z 2371 (2000). In addition, exposure treatment according to salt water immersion and various exposure tests (for example, the exposure test method described in Table 1 of JIS Z 2381 (2001) General Rules for Atmospheric Exposure Test Methods) can be used, and there is no particular limitation. The composition and the test environment (temperature, humidity, etc.) of the corrosive liquid used for the corrosion progress treatment can also be appropriately selected. Moreover, the time for the above-described corrosion progress treatment can also be selected as appropriate. For example, it can be as long as about 100 hours as in the conventional case, but this is not preferable because it increases the time until final evaluation. In particular, if it is 24 hours or less, 3 hours or less, especially 30 minutes or less, the time until the final evaluation is short, and it is expected to be suitable for practical use. As shown in a test example to be described later, it is expected that the corrosion resistance can be sufficiently evaluated in about 5 minutes or depending on the composition of the test piece in about 1 minute.
上記腐食反応抵抗は、交流インピーダンス測定の結果を解析して算出する。算出方法の詳細は後述する。 The corrosion reaction resistance is calculated by analyzing the result of AC impedance measurement. Details of the calculation method will be described later.
上記交流インピーダンス測定には、電気化学測定を利用する。この測定には、市販のポテンショスタット/ガルバノスタット装置を好適に利用することができ、このような装置により測定結果を容易に把握できる。 Electrochemical measurement is used for the AC impedance measurement. For this measurement, a commercially available potentiostat / galvanostat device can be suitably used, and the measurement result can be easily grasped by such a device.
そして、本発明では、上記腐食進行処理前後の腐食反応抵抗により、耐食性を評価することを最大の特徴とする。上述したように腐食進行処理前における腐食反応抵抗の絶対値は、耐食性の指標とすることができ、例えば、当該絶対値が低い場合、耐食性に劣る、と評価する。本発明評価方法では、上記腐食進行処理前における絶対値の大小による耐食性の評価に加えて、上記腐食進行処理後の腐食反応抵抗と当該処理前の値(初期値)との大小の比較をも耐食性の指標に利用する。例えば、上記初期値の絶対値がある程度大きく、かつ上記腐食進行処理後の腐食反応抵抗が上記初期値よりも大きいとき、耐食性に優れ、上記初期値と同等以下のとき(小さいとき)、耐食性に劣る、と評価することができる。また、上記腐食進行処理後の腐食反応抵抗が上記初期値よりも大きくても、上記初期値の絶対値が小さい場合、耐食性に劣る、と評価することができる。そして、上記いずれの場合も、耐食性に優れる度合いや劣る度合いを定量的に評価することができる。特に、本発明者らが調べたところ、マグネシウム合金材では、上記腐食進行処理の開始直後からある程度短い時間の範囲においては、当該処理後の測定値が初期値よりも大きくなる、即ち、当該処理前よりも耐食性が向上している場合がある、との知見を得た。そして、耐食性に優れるマグネシウム合金材の場合、上記腐食進行処理の処理時間が30分程度、更には10分以下であっても、当該処理後の測定値が初期値よりも十分に大きい、具体的には2倍以上となっている場合があるとの知見を得た。そこで、本発明では、耐食性に優れるとの評価を行う基準として、上記腐食進行処理の処理時間が10分以下であるときの上記測定値が初期値の2倍以上であることを提案する。 In the present invention, the greatest feature is that the corrosion resistance is evaluated based on the corrosion reaction resistance before and after the above-described corrosion progress treatment. As described above, the absolute value of the corrosion reaction resistance before the corrosion progress treatment can be used as an index of corrosion resistance. For example, when the absolute value is low, it is evaluated that the corrosion resistance is inferior. In the evaluation method of the present invention, in addition to the evaluation of the corrosion resistance based on the magnitude of the absolute value before the corrosion progression treatment, the corrosion reaction resistance after the corrosion progression treatment is compared with the value (initial value) before the treatment. Used as an indicator of corrosion resistance. For example, when the absolute value of the initial value is somewhat large and the corrosion reaction resistance after the corrosion progress treatment is larger than the initial value, the corrosion resistance is excellent, and when it is equal to or less than the initial value (when small), the corrosion resistance is improved. It can be evaluated as inferior. In addition, even if the corrosion reaction resistance after the corrosion progress treatment is larger than the initial value, it can be evaluated that the corrosion resistance is poor when the absolute value of the initial value is small. In either case, the degree of corrosion resistance and the degree of inferiority can be quantitatively evaluated. In particular, as a result of investigation by the present inventors, in the case of a magnesium alloy material, the measured value after the treatment becomes larger than the initial value in a short time range immediately after the start of the corrosion progress treatment, that is, the treatment. The knowledge that the corrosion resistance may be improved than before was obtained. And in the case of a magnesium alloy material with excellent corrosion resistance, even if the processing time of the above-mentioned corrosion progress treatment is about 30 minutes, and even 10 minutes or less, the measured value after the treatment is sufficiently larger than the initial value, It was found that there is a case where the number of the cases is twice or more. Therefore, the present invention proposes that the above measured value when the processing time of the corrosion progressing treatment is 10 minutes or less is twice or more of the initial value as a standard for evaluating that the corrosion resistance is excellent.
なお、後述するように、上記腐食進行処理の処理時間を長くすると、マグネシウム合金材のうち、耐食性に劣るものは、腐食反応抵抗が徐々に低下し、例えば、当該処理時間を100時間程度とすると、上記腐食進行処理後の測定値が初期値よりも小さくなる。即ち、上記腐食進行処理前よりも耐食性に劣った状態となる。これに対し、耐食性に優れるマグネシウム合金材の中には、上記腐食進行処理時間が100時間程度であっても、上記腐食進行処理後の測定値が初期値よりも大きいままのものがある、即ち、当該処理前よりも耐食性に優れた状態になっているものがある、という驚くべき知見を得た。従って、腐食進行処理の処理時間を長くする場合も、上記腐食進行処理後の測定値と初期値との大小を比較することで、耐食性を評価することができると言える。 As will be described later, when the treatment time of the corrosion progress treatment is lengthened, among the magnesium alloy materials, those having poor corrosion resistance are gradually reduced in corrosion reaction resistance, for example, when the treatment time is about 100 hours. The measured value after the corrosion progress treatment is smaller than the initial value. That is, the corrosion resistance is inferior to that before the corrosion progress treatment. On the other hand, among the magnesium alloy materials having excellent corrosion resistance, there are those in which the measured value after the corrosion progress treatment remains larger than the initial value even when the corrosion progress time is about 100 hours. As a result, the inventors have obtained a surprising finding that there are those that are in a state of better corrosion resistance than before the treatment. Therefore, even when the processing time of the corrosion progress treatment is increased, it can be said that the corrosion resistance can be evaluated by comparing the measured value after the corrosion progress treatment with the initial value.
以下、本発明の実施の形態を説明する。
[参照試験]
複数のマグネシウム合金板を用意し、各マグネシウム合金板の耐食性を調べた。
Embodiments of the present invention will be described below.
[Reference test]
A plurality of magnesium alloy plates were prepared, and the corrosion resistance of each magnesium alloy plate was examined.
この試験では、以下のように作製した試料No.1〜3のマグネシウム合金板と、市販の鋳造材(AZ91合金、厚さ3mmの板)、市販の展伸材(AZ31合金、厚さ1mmの板)を用意した。上記鋳造材及び展伸材に、後述する湿式研磨を施して研磨板を作製し、この研磨板をそれぞれ試料No.4,5とした。 In this test, the magnesium alloy plates of Sample Nos. 1 to 3 prepared as follows, a commercially available cast material (AZ91 alloy, 3 mm thick plate), a commercially available wrought material (AZ31 alloy, 1 mm thick) Board). The cast material and the wrought material were subjected to wet polishing, which will be described later, to produce a polishing plate, and these polishing plates were designated as Sample Nos. 4 and 5, respectively.
(試料No.1〜3)
AZ91合金相当の組成を有するマグネシウム合金(代表的な添加元素:Al(9.0質量％))からなり、双ロール連続鋳造法により得られた鋳造板(厚さ4mm、所定の長さに切断されたシート状のもの)を複数用意した。得られた各鋳造板に、400℃×24時間の溶体化処理を施した。溶体化処理を施した各固溶板に以下の圧延条件で複数回圧延を施し、厚さ0.6mmの圧延板を作製した。
(Sample Nos. 1 to 3)
A cast plate (thickness 4 mm, cut to a predetermined length) made of a magnesium alloy having a composition equivalent to AZ91 alloy (typical additive element: Al (9.0 mass%)) and obtained by a twin roll continuous casting method Several sheets were prepared. Each obtained cast plate was subjected to a solution treatment at 400 ° C. for 24 hours. Each solid solution plate subjected to solution treatment was rolled a plurality of times under the following rolling conditions to produce a rolled plate having a thickness of 0.6 mm.
圧延条件(1) 粗圧延:6パス
圧延条件(2) 粗圧延:5パス、仕上げ圧延:2パス
粗圧延の条件は、加工度(圧下率):5％/パス〜40％/パス、素材板の加熱温度:250℃〜280℃、ロール温度:100℃〜250℃、
仕上げ圧延の条件は、加工度(圧下率):5％/パス〜40％/パス、素材板の加熱温度:210℃〜240℃、ロール温度:150℃〜180℃である。
Rolling conditions (1) Rough rolling: 6 passes Rolling conditions (2) Rough rolling: 5 passes, Finish rolling: 2 passes The conditions for rough rolling are: Degree of processing (rolling rate): 5% / pass to 40% / pass, material Heating temperature of plate: 250 ° C to 280 ° C, roll temperature: 100 ° C to 250 ° C,
The conditions for finish rolling are a working degree (rolling rate): 5% / pass to 40% / pass, a heating temperature of the base plate: 210 ° C. to 240 ° C., and a roll temperature: 150 ° C. to 180 ° C.
得られた各圧延板を250℃に加熱した状態で温間矯正を施して、矯正板を作製した。上記温間矯正は、圧延板を加熱可能な加熱炉と、加熱された圧延板に連続的に曲げ(歪)を付与する複数のロールを有するロール部とを具えるロールレベラ装置を用いて行う。上記ロール部は、上下に対向して千鳥状に配置された複数のロールを具える。上記ロールレベラ装置により、圧延板は、上記加熱炉内で加熱されながら上記ロール部に送られ、ロール部の上下のロール間を通過するごとに、これらのロールにより順次曲げが付与される。 Each of the obtained rolled plates was warm-corrected in a state heated to 250 ° C. to produce a corrected plate. The warm correction is performed using a roll leveler apparatus that includes a heating furnace capable of heating a rolled plate and a roll unit having a plurality of rolls that continuously bend (strain) the heated rolled plate. The roll section includes a plurality of rolls arranged in a staggered manner facing each other in the vertical direction. With the roll leveler device, the rolled plate is fed to the roll part while being heated in the heating furnace, and each time it passes between the upper and lower rolls of the roll part, the roll is sequentially bent.
試料No.1:上記圧延条件(1)の圧延を施して得られた圧延板に、後述する湿式研磨を施し、得られた研磨板。
試料No.2:上記圧延条件(1)の圧延を施して得られた圧延板に、400℃×25時間の溶体化処理を施した後、後述する湿式研磨を施し、得られた研磨板。
試料No.3:上記圧延条件(2)の圧延を施して得られた圧延板に、後述する湿式研磨を施して得られた研磨板。
上記湿式研磨:＃600の研磨ベルトを用いて湿式ベルト式研磨を利用
なお、試料No.1,3はいずれも、溶体化処理以降の製造工程において、150℃〜300℃の温度域に保持する総合計時間を1時間〜12時間とすると共に、300℃超の加熱を行わないようにした。試料No.2は、1回目の溶体化処理以降の製造工程において、2回目の溶体化処理を除いて、150℃〜300℃の温度域に保持する総合計時間を1時間〜12時間とすると共に、300℃超の加熱を行わないようにした。
Sample No. 1: A polished plate obtained by subjecting a rolled plate obtained by rolling under the rolling condition (1) to wet polishing described later.
Sample No. 2: A polished plate obtained by subjecting a rolled plate obtained by rolling under the above rolling condition (1) to a solution treatment at 400 ° C. for 25 hours, followed by wet polishing described later.
Sample No. 3: A polished plate obtained by subjecting a rolled plate obtained by rolling under the rolling condition (2) to wet polishing described later.
The above wet polishing: Wet type polishing is used with a # 600 polishing belt. Samples Nos. 1 and 3 are kept in a temperature range of 150 ° C. to 300 ° C. in the manufacturing process after solution treatment. The total time was 1 to 12 hours, and heating above 300 ° C. was not performed. Sample No. 2 has a total time of 1 hour to 12 hours held in the temperature range of 150 ° C. to 300 ° C., excluding the second solution treatment in the manufacturing process after the first solution treatment. At the same time, heating above 300 ° C. was not performed.
得られた試料No.1〜3、及び用意した試料No.4,5をそれぞれ板厚方向に任意に切断して断面をとり、その断面を走査電子顕微鏡:SEMで観察したところ、試料No.1,3は、金属間化合物(例えば、Mg17Al12など)からなり、丸みを帯びた小さな粒子(平均粒径0.5μm以下)が均一的に分散した組織を有しており、ダイカスト材である試料No.4は、金属間化合物(例えば、Mg17Al12など)からなり、異形の大きな粒子がまばらに存在した組織であった。試料No.2,5は、試料No.1,3で観察された粒子よりも更に小さな粒子(例えば、Al-Mn-Feなど)が少量、分散した組織であった。 The obtained sample Nos. 1 to 3 and the prepared sample Nos. 4 and 5 were each arbitrarily cut in the plate thickness direction to take a cross section, and the cross section was observed with a scanning electron microscope: SEM. 1 and 3 are made of an intermetallic compound (for example, Mg 17 Al 12 ), and have a structure in which small round particles (average particle size of 0.5 μm or less) are uniformly dispersed. One sample No. 4 was composed of an intermetallic compound (for example, Mg 17 Al 12 ), and had a structure in which large irregularly shaped particles were present sparsely. Samples Nos. 2 and 5 were structures in which a smaller amount of particles (for example, Al-Mn-Fe, etc.) smaller than the particles observed in sample Nos. 1 and 3 were dispersed.
用意した試料No.1〜5に対して、以下の腐食進行処理(いずれも96時間)を行い、当該処理前後の腐食反応抵抗(Ω)、当該処理による腐食減量(μg/cm2)、当該処理によるMg溶出量(μg/cm2)を測定した。その結果を表1に示す。 For the prepared samples No. 1 to 5, the following corrosion progress treatment (each 96 hours) is performed, the corrosion reaction resistance before and after the treatment (Ω), the weight loss due to the treatment (μg / cm 2 ), the relevant The amount of Mg elution (μg / cm 2 ) by the treatment was measured. The results are shown in Table 1.
腐食減量は、腐食進行処理として、JIS H 8502(1999)に準拠して塩水噴霧試験を行い、以下のように測定した。試料No.1〜5の研磨板から試験片を作製し、試験片の質量(初期質量)を測定した後、試験片において予め設定した大きさの試験面が露出するように、試験片の不要な箇所にマスキングを施す。マスキングした試験片を腐食試験装置内に装入し、当該装置底面に対して所定の角度に傾斜するように試験片を立て掛けて配置する(ここでは、装置底面と試験片とがつくる角:70°〜80°)。腐食液(ここでは、5質量％のNaCl水溶液、温度:35±2℃)を霧状にして試験片に吹き掛けた状態で96時間保持する。96時間経過後、試験片を腐食試験装置から取り出して、マスキングを除去した後、JIS Z 2371(2000)の参考表1に記載の方法に準拠して、試験片に生成された腐食生成物をクロム酸溶解により除去する。腐食生成物を除去した後の試験片の質量を測定し、この質量と上記初期質量との差分を試験片の試験面の面積で除した値を腐食減量(μg/cm2)とする。 Corrosion weight loss was measured as follows by conducting a salt spray test in accordance with JIS H 8502 (1999) as corrosion progress treatment. After preparing a test piece from the polishing plate of sample No. 1-5 and measuring the mass (initial mass) of the test piece, the test piece is unnecessary so that the test surface of a preset size is exposed on the test piece Apply masking to various parts. The masked test piece is inserted into the corrosion test apparatus, and the test piece is placed so as to be inclined at a predetermined angle with respect to the apparatus bottom face (here, the angle formed by the apparatus bottom face and the test piece: 70 ° ~ 80 °). A corrosive solution (here, 5 mass% NaCl aqueous solution, temperature: 35 ± 2 ° C.) is sprayed on the test piece in the form of a mist and held for 96 hours. After 96 hours, remove the test piece from the corrosion test equipment and remove the masking. Then, in accordance with the method described in Reference Table 1 of JIS Z 2371 (2000), the corrosion product generated on the test piece is removed. Remove by dissolving chromic acid. The mass of the test piece after removing the corrosion product is measured, and a value obtained by dividing the difference between this mass and the initial mass by the area of the test surface of the test piece is defined as corrosion weight loss (μg / cm 2 ).
Mg溶出量は、腐食進行処理として、以下の条件で塩水浸漬試験を行い、以下のように測定した。試料No.1〜5の研磨板から試験片を作製し、試験片において予め設定した大きさの試験面が露出するように、試験片の不要な箇所にマスキングを施す。マスキングした試験片を腐食液(ここでは、5質量％のNaCl水溶液、液量:試験片の試験面の面積(露出面積)を(A)cm2としたとき、(A)×20mlとする)に完全に浸漬した状態で96時間保持する(ここでは、空調下の室温(25±2℃)に保持)。96時間経過後、腐食液を回収し、ICP-AES(誘導結合プラズマ発光分光)分析法にて、腐食液中のMgイオン量を定量し、Mgイオン量を試験片の試験面の面積で除した値をMg溶出量(μg/cm2)とする。 The amount of Mg elution was measured as follows by conducting a salt water immersion test under the following conditions as a corrosion progress treatment. Test pieces are prepared from the polishing plates of Sample Nos. 1 to 5, and unnecessary portions of the test pieces are masked so that a test surface having a predetermined size is exposed on the test pieces. Masked test piece is corrosive solution (here, 5% by weight NaCl aqueous solution, liquid amount: (A) x 2 ml when the test piece area (exposed area) is (A) cm 2 ) For 96 hours (here, kept at room temperature (25 ± 2 ° C.) under air conditioning). After 96 hours, the corrosive liquid is collected, and the amount of Mg ions in the corrosive liquid is quantified by ICP-AES (inductively coupled plasma emission spectroscopy) analysis, and the amount of Mg ions is divided by the area of the test surface of the test piece. The obtained value is defined as the Mg elution amount (μg / cm 2 ).
腐食反応抵抗は、以下のように測定した。試料No.1〜5の研磨板から試験片を作製し、試験片において予め設定した大きさの試験面、及び端子接続部分が露出するように試験片の不要な箇所にマスキングを施す。上記端子接続部分に端子を取り付け、この試験片の試験面を下記の参照電極及び対極と共に、試験液(ここでは、(0.1質量％のNaCl)＋Mg(OH)2飽和水溶液)に完全に浸漬する(ここでは、空調下の室温(25±2℃))。そして、浸漬直後において、下記の条件にて試験片の交流インピーダンス測定を行う。 The corrosion reaction resistance was measured as follows. Test pieces are prepared from the polishing plates of Samples Nos. 1 to 5, and masking is performed on unnecessary portions of the test pieces so that the test surface and the terminal connection portion of the preset size are exposed on the test pieces. A terminal is attached to the terminal connection portion, and the test surface of the test piece is completely immersed in a test solution (here, (0.1 mass% NaCl) + Mg (OH) 2 saturated aqueous solution) together with the following reference electrode and counter electrode. (In this case, room temperature under air conditioning (25 ± 2 ℃)). Then, immediately after the immersion, the AC impedance of the test piece is measured under the following conditions.
測定装置:ポテンショスタット/ガルバノスタット＋周波数応答解析装置
上記測定装置は、市販の装置(例えば、北斗電工株式会社製 HZ-3000、株式会社エヌエフ回路設計ブロック製 FRA5080など)を利用することができる。
電極:3電極式、参照電極:Ag/AgCl、対極:Pt
測定条件:電流変調モード:10μA/cm2、測定周波数範囲:10kHz〜100mHz
Measuring device: Potentiostat / galvanostat + frequency response analyzer The commercially available device (for example, HZ-3000 manufactured by Hokuto Denko Co., Ltd., FRA5080 manufactured by NF Circuit Design Block Co., Ltd., etc.) can be used as the measuring device.
Electrode: 3-electrode type, reference electrode: Ag / AgCl, counter electrode: Pt
Measurement conditions: Current modulation mode: 10 μA / cm 2 , Measurement frequency range: 10 kHz to 100 mHz
交流インピーダンス測定の結果を解析して、腐食反応抵抗を算出する。具体的には、各周波数で計測したインピーダンス(Ω)を複素平面上にプロットし(ナイキスト線図を作図し)、高周波領域に観察される半円の直径(＝電荷移動抵抗)を読み取る。この電荷移動抵抗を腐食反応抵抗とする。上記塩水浸漬試験を行った試験片に同様に端子を取り付けて、同様にして交流インピーダンス測定を実施し、腐食反応抵抗を読み取る。このときの腐食反応抵抗を腐食試験後(ここでは96時間の塩水浸漬試験後)の腐食反応抵抗とし、当該塩水浸漬試験を行う前に測定した腐食反応抵抗を初期値とする。 Analyze the results of the AC impedance measurement to calculate the corrosion reaction resistance. Specifically, the impedance (Ω) measured at each frequency is plotted on a complex plane (a Nyquist diagram is drawn), and the diameter of the semicircle (= charge transfer resistance) observed in the high frequency region is read. This charge transfer resistance is defined as a corrosion reaction resistance. A terminal is similarly attached to the test piece subjected to the salt water immersion test, and AC impedance measurement is performed in the same manner to read the corrosion reaction resistance. The corrosion reaction resistance at this time is taken as the corrosion reaction resistance after the corrosion test (96 hours after the salt water immersion test), and the corrosion reaction resistance measured before the salt water immersion test is taken as the initial value.
表1に示すように、試料No.1〜3は、ダイカスト材からなる試料No.4、Alの含有量が少ない試料No.5と比較して、腐食減量が非常に少なく、Mgの溶出量も少なく、耐食性に優れることが分かる。また、試料No.1〜4は、Alの含有量が少ない試料No.5と比較して、腐食反応抵抗の初期値(絶対値)が高く、耐食性に優れることが分かる。 As shown in Table 1, sample Nos. 1 to 3 are very low in corrosion weight loss and Mg elution compared to sample No. 4 made of die cast material and sample No. 5 with low Al content. There are few, and it turns out that it is excellent in corrosion resistance. In addition, it can be seen that Sample Nos. 1 to 4 have a higher initial value (absolute value) of corrosion reaction resistance and excellent corrosion resistance than Sample No. 5 having a low Al content.
更に、試料No.1〜3は、上述した塩水を用いた腐食進行処理(96H)後の交流インピーダンス測定による腐食反応抵抗が当該試験前よりも高く、耐食性が向上していることが分かる。この結果から、耐食性に優れることの一つの指標として、腐食進行処理前後における腐食反応抵抗の変化を利用できると考えられる。そこで、塩水浸漬や塩水噴霧といった腐食進行処理の前後において、交流インピーダンス法により腐食反応抵抗を測定し、これら測定結果を耐食性の評価に利用する妥当性を検討した。 Furthermore, it can be seen that Samples Nos. 1 to 3 have higher corrosion resistance than those before the test because the corrosion resistance by AC impedance measurement after the above-described corrosion progression treatment using salt water (96H) is higher. From this result, it is considered that the change in the corrosion reaction resistance before and after the corrosion progress treatment can be used as one index of excellent corrosion resistance. Therefore, the corrosion reaction resistance was measured by the AC impedance method before and after the corrosion progress treatment such as salt water immersion or salt spray, and the validity of using these measurement results for the evaluation of corrosion resistance was examined.
[試験例]
複数のマグネシウム合金板を用意し、以下の腐食進行処理を、処理時間を変化させて施し、当該処理後の腐食反応抵抗を調べた。
[Test example]
A plurality of magnesium alloy plates were prepared, and the following corrosion progress treatment was performed while changing the treatment time, and the corrosion reaction resistance after the treatment was examined.
この試験では、マグネシウム合金板として、上記参照試験で用いた試料No.1〜5の研磨板を用意して、上記参照試験と同様にして試験片を作製した。試験片は、腐食進行処理を行うにあたり、表面荒れによる腐食状態のばらつきなどが生じないように表面性状を整えることが好ましい。この表面性状の調整には、研磨などの前処理を施すことが挙げられる。研磨紙(例えば、＃2000程度のもの)を用いて研磨してもよいし、上述のように研磨板を用いる場合は、この前処理を省略してもよい。各試験片は、マスキングにより所定の大きさの試験面だけを露出させる。ここでは、PTFE(ポリテトラフルオロエチレン)によりマスキングを行い、試験面の露出面積を4cm2とした。マスキングには、PTFEやシリコーンゴムといった樹脂の他、耐食性に優れ、試験液と反応しない種々の材料が利用できる。露出面積は適宜選択することができる。 In this test, polishing plates of Sample Nos. 1 to 5 used in the above reference test were prepared as magnesium alloy plates, and test pieces were produced in the same manner as in the above reference test. It is preferable to arrange the surface properties of the test piece so as not to cause a variation in the corrosion state due to surface roughness when the corrosion progressing treatment is performed. For the adjustment of the surface property, pretreatment such as polishing may be performed. You may grind | polish using abrasive paper (for example, about # 2000), and when using a grinding | polishing board as mentioned above, you may abbreviate | omit this pre-processing. Each test piece exposes only a test surface of a predetermined size by masking. Here, masking was performed with PTFE (polytetrafluoroethylene), and the exposed area of the test surface was 4 cm 2 . In addition to resins such as PTFE and silicone rubber, various materials that have excellent corrosion resistance and do not react with the test solution can be used for masking. The exposed area can be selected as appropriate.
用意した上記試験片に腐食進行処理として、上記参照試験と同様の腐食液(5質量％のNaCl水溶液)を用い、同様の条件で塩水浸漬試験を行った(空調下の室温(25±2℃)に保持)。処理時間(試験片の試験面が完全に浸漬した状態での保持時間)は、表2に示すように、5分、10分、30分、60分、180分、1440分とした。そして、上記腐食進行処理(ここでは塩水浸漬試験)前、及び当該処理を所定の処理時間行った後についてそれぞれ、上記参照試験と同様の条件で同様にして交流インピーダンス測定を行い、腐食反応抵抗を読み取った。その結果を表2に示す。 The prepared test piece was subjected to a salt water immersion test under the same conditions using a corrosive solution (5 mass% NaCl aqueous solution) similar to the above reference test as corrosion progress treatment (room temperature under air conditioning (25 ± 2 ° C) )). As shown in Table 2, the treatment time (holding time when the test surface of the test piece was completely immersed) was 5 minutes, 10 minutes, 30 minutes, 60 minutes, 180 minutes, and 1440 minutes. Then, before the corrosion progress treatment (here, salt water immersion test) and after the treatment has been performed for a predetermined treatment time, respectively, AC impedance measurement was performed in the same conditions as in the reference test, and the corrosion reaction resistance was determined. I read it. The results are shown in Table 2.
図2に示すように、腐食進行処理の処理時間が30分以内の場合、試料No.1〜5のいずれも、目視による確認では腐食状態に差が見られず、耐食性の優劣を判別することが実質的にできない。また、図1,表2に示すように、この試験例に用いたマグネシウム合金材はいずれも、腐食進行処理の処理時間が24時間以内であれば、当該処理前の腐食反応抵抗(初期値)よりも、当該処理後の測定値の方が高くなっており、同じような傾向を示すと言える。 As shown in Fig. 2, when the processing time of the corrosion progressing treatment is within 30 minutes, any of sample Nos. 1 to 5 can be visually checked to determine whether the corrosion state is different, and whether the corrosion resistance is superior or inferior. Is virtually impossible. In addition, as shown in FIG. 1 and Table 2, the magnesium alloy materials used in this test example all have a corrosion reaction resistance (initial value) before the treatment if the treatment time of the corrosion progression treatment is within 24 hours. It can be said that the measured value after the treatment is higher than that, indicating a similar tendency.
しかし、図1,表2に示すように、耐食性の優劣によって、腐食反応抵抗の初期値に対する腐食進行処理後の測定値の上昇度合い(比率)が異なる。具体的には、参照試験で耐食性に優れると評価された試料No.1〜3は、処理時間が5分といった短時間で、当該処理後の腐食反応抵抗の測定値が初期値の1.5倍以上になっている。更に、試料No.1〜3は、処理時間が10分以内で、当該処理後の腐食反応抵抗の測定値が初期値の2倍以上になっている。これに対して、参照試験で耐食性に劣ると評価された試料No.4,5は、上記上昇度合いが小さいことが分かる。 However, as shown in FIG. 1 and Table 2, the degree of increase (ratio) of the measured value after the corrosion progress treatment with respect to the initial value of the corrosion reaction resistance varies depending on the superiority or inferiority of the corrosion resistance. Specifically, sample Nos. 1 to 3, which were evaluated as having excellent corrosion resistance in the reference test, had a treatment time of 5 minutes and the measured value of the corrosion reaction resistance after the treatment was 1.5 times or more of the initial value. It has become. Further, Sample Nos. 1 to 3 have a treatment time of 10 minutes or less, and the measured values of the corrosion reaction resistance after the treatment are more than twice the initial value. On the other hand, sample Nos. 4 and 5 evaluated as inferior in corrosion resistance in the reference test show that the degree of increase is small.
このことから、マグネシウム合金材の耐食性の評価にあたり、上述のように塩水浸漬などの腐食進行処理の前後において腐食反応抵抗の大小を比較することに妥当性があると言える。 From this, it can be said that in the evaluation of the corrosion resistance of the magnesium alloy material, it is appropriate to compare the magnitude of the corrosion reaction resistance before and after the corrosion progress treatment such as salt water immersion as described above.
また、上述のように10分以内で、上記腐食進行処理後の腐食反応抵抗の測定値と初期値との差が十分にみられる。従って、腐食進行処理の前後における腐食反応抵抗の大小を比較するという手法は、上記腐食進行処理前の腐食反応抵抗の大小に差が無い場合や目視確認では困難と考えられるような非常に短時間の腐食進行処理を施した場合であっても、耐食性の評価を良好に行え、耐食性の評価にあたり、従来と比較して画期的に時間を短縮できると言える。特に、この手法では、腐食反応抵抗という数値を利用することで、耐食性の評価を定量的に行うことができ、目視確認の場合のような評価のばらつきが実質的に生じない。このように電気化学測定を利用する本発明評価方法は、従来の評価方法と比較して、非常に短時間で、かつ精度良く定量的に耐食性を評価でき、有用性が高いと期待される。 Further, as described above, the difference between the measured value and the initial value of the corrosion reaction resistance after the corrosion progress treatment is sufficiently observed within 10 minutes. Therefore, the method of comparing the magnitude of the corrosion reaction resistance before and after the corrosion progress treatment is very short in time when there is no difference in the magnitude of the corrosion reaction resistance before the corrosion progress treatment or when visual confirmation is considered difficult. Even when the corrosion progressing treatment is performed, it can be said that the corrosion resistance can be evaluated satisfactorily, and the time can be dramatically shortened in comparison with the conventional one when evaluating the corrosion resistance. In particular, in this method, the corrosion resistance can be quantitatively evaluated by using a numerical value called corrosion reaction resistance, and the evaluation variation as in the case of visual confirmation does not substantially occur. As described above, the evaluation method of the present invention using electrochemical measurement is expected to be highly useful in that the corrosion resistance can be evaluated quantitatively in a very short time with high accuracy compared with the conventional evaluation method.
なお、上述した実施形態は、本発明の要旨を逸脱することなく、適宜変更することが可能であり、上述した構成に限定されるものではない。例えば、腐食進行処理として、塩水噴霧試験、各種の暴露試験などを利用したり、腐食反応抵抗を測定するための試験液の組成、処理環境、測定条件などを適宜変更することができる。また、例えば、種々の組成や製造方法によりマグネシウム合金材を作製して、上述のように短時間の腐食進行試験を行った前後の腐食反応抵抗を測定して上述のように初期値に対する比率を求め、この比率を照合データに利用すると、マグネシウム合金材の耐食性を簡単に、短時間で、かつ精度良く定量的に評価できると期待される。その他、上述した耐食性の評価方法は、マグネシウム合金と同様に腐食反応によって保護性の被膜が形成される金属材料(例えばアルミニウム、ステンレス合金、ニッケルなど)からなる部材を評価対象に利用できる可能性がある。 The above-described embodiment can be appropriately changed without departing from the gist of the present invention, and is not limited to the above-described configuration. For example, as the corrosion progress treatment, a salt spray test, various exposure tests, and the like can be used, and the composition of the test solution for measuring the corrosion reaction resistance, the treatment environment, the measurement conditions, and the like can be appropriately changed. In addition, for example, magnesium alloy materials are produced by various compositions and manufacturing methods, and the corrosion reaction resistance before and after performing a short-time corrosion progress test as described above is measured, and the ratio to the initial value is determined as described above. When this ratio is obtained and used as collation data, it is expected that the corrosion resistance of the magnesium alloy material can be easily and quantitatively evaluated in a short time with high accuracy. In addition, the above-described corrosion resistance evaluation method may be able to use a member made of a metal material (for example, aluminum, stainless alloy, nickel, etc.) on which a protective film is formed by a corrosion reaction in the same manner as a magnesium alloy. is there.
本発明は、各種の電気・電子機器類の構成部材、特に、携帯用や小型な電気・電子機器類の筐体、高強度であることが望まれる種々の分野の部材に利用されるマグネシウム合金材の耐食性を評価する際に好適に利用することができる。特に、本発明は、サンプル品の出来栄えの確認といった短時間での評価が望まれる場合に好適に利用することができる。 The present invention relates to a component of various electric / electronic devices, in particular, a magnesium alloy used for a portable or small-sized casing of electric / electronic devices, members of various fields where high strength is desired. It can utilize suitably when evaluating the corrosion resistance of a material. In particular, the present invention can be suitably used when evaluation in a short time such as confirmation of the quality of a sample product is desired.
Claims (2)
前記マグネシウム合金材に腐食進行処理を行い、前記腐食進行処理が施されたマグネシウム合金材に対して交流インピーダンス法により腐食反応抵抗を測定し、
前記測定値と、前記腐食進行処理前におけるマグネシウム合金材の腐食反応抵抗値との大小を比較することで、耐食性を評価することを特徴とするマグネシウム合金材の耐食性の評価方法。 A method for evaluating the corrosion resistance of a magnesium alloy material for evaluating the corrosion resistance of a magnesium alloy material,
Corrosion progress treatment is performed on the magnesium alloy material, and the corrosion reaction resistance is measured by an AC impedance method for the magnesium alloy material subjected to the corrosion progress treatment,
A method for evaluating the corrosion resistance of a magnesium alloy material, characterized in that the corrosion resistance is evaluated by comparing the measured value with the corrosion reaction resistance value of the magnesium alloy material before the corrosion progress treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010059761A JP2011191270A (en) | 2010-03-16 | 2010-03-16 | Method for evaluating corrosion resistance of magnesium alloy material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010059761A JP2011191270A (en) | 2010-03-16 | 2010-03-16 | Method for evaluating corrosion resistance of magnesium alloy material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2011191270A true JP2011191270A (en) | 2011-09-29 |
Family
ID=44796349
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2010059761A Pending JP2011191270A (en) | 2010-03-16 | 2010-03-16 | Method for evaluating corrosion resistance of magnesium alloy material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2011191270A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103091244A (en) * | 2013-01-15 | 2013-05-08 | 安徽省电力科学研究院 | Laboratory electrochemical evaluation method of corrosion resistance of grounding material of electric transmission and transformation equipment |
| CN106814026A (en) * | 2015-12-02 | 2017-06-09 | 鞍钢股份有限公司 | A kind of clad plate corrosion resisting property method for rapidly testing |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009228087A (en) * | 2008-03-25 | 2009-10-08 | Hiroshima Univ | Magnesium alloy coating film and method for producing the same |
-
2010
- 2010-03-16 JP JP2010059761A patent/JP2011191270A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009228087A (en) * | 2008-03-25 | 2009-10-08 | Hiroshima Univ | Magnesium alloy coating film and method for producing the same |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103091244A (en) * | 2013-01-15 | 2013-05-08 | 安徽省电力科学研究院 | Laboratory electrochemical evaluation method of corrosion resistance of grounding material of electric transmission and transformation equipment |
| CN106814026A (en) * | 2015-12-02 | 2017-06-09 | 鞍钢股份有限公司 | A kind of clad plate corrosion resisting property method for rapidly testing |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ryl et al. | Effect of native air-formed oxidation on the corrosion behavior of AA 7075 aluminum alloys | |
| Delgado et al. | Influence of aluminium enrichment in the near-surface region of commercial twin-roll cast AZ31 alloys on their corrosion behaviour | |
| RU2371516C2 (en) | Hydroxy-sulphate treatment of surface | |
| Guo et al. | Effects of benzotriazole on anodized film formed on AZ31B magnesium alloy in environmental-friendly electrolyte | |
| CN110411934B (en) | Rapid assessment and prediction method for corrosion grade of aluminum alloy | |
| Talha et al. | Long term and electrochemical corrosion investigation of cold worked AISI 316L and 316LVM stainless steels in simulated body fluid | |
| Mena-Morcillo et al. | Multi-scale monitoring the first stages of electrochemical behavior of AZ31B magnesium alloy in simulated body fluid | |
| Niu et al. | Wear and corrosion behavior of Mg–Gd–Y–Zr alloy treated by mixed molten-salt bath | |
| Seikh et al. | Microstructure characterization and corrosion resistance properties of Pb-Sb alloys for lead acid battery spine produced by different casting methods | |
| Nam et al. | Corrosion behavior of Mg–5Al–xZn alloys in 3.5 wt.% NaCl solution | |
| TW201202437A (en) | Magnesium alloy plate | |
| Maier et al. | Solid solution treatment on strength and corrosion of biodegradable Mg6Ag wires | |
| JP2011191270A (en) | Method for evaluating corrosion resistance of magnesium alloy material | |
| JP2010025560A (en) | Corrosion resistance evaluating method of metal material | |
| EP4079942A1 (en) | Ni-plated steel sheet and method for manufacturing ni-plated steel sheet | |
| JP3893358B2 (en) | Phosphor bronze strip with excellent bending workability | |
| Zhou et al. | Corrosion behavior of the Al2Cu intermetallic compound and coupled Al2Cu/Al | |
| Wang et al. | Corrosion behavior of 907 steel under thin electrolyte layers of artificial seawater | |
| JP2017003372A (en) | Method for measuring plating thickness of plating material, method for measuring amount of corrosion of plating material, and corrosion sensor of plating material | |
| Grabowski et al. | Influence of Ca2+ in deicing salt on the corrosion behavior of AM50 magnesium alloy | |
| Wang et al. | Electrochemical studies of the corrosion behavior of carbon and weathering steels in alternating wet/dry environments with sulfur dioxide gas | |
| JP6534446B2 (en) | Method of manufacturing plate material for electrochemical process | |
| Zhang et al. | Galvanic Corrosion Behavior of 907A/Titanium Couple in Simulated Seawater | |
| Sharifi | Structure-Property Relationships of Magnesium Alloys | |
| Matter et al. | Correlation between preliminary pretreatments and the behaviour of AA-2024–aluminium alloy in 3.5% NaCl model corrosive medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20130313 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20131016 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20131023 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20140306 |