Lepera試劑.doc

LePeras reagent所謂Lepera試劑（Le Pera ）就是：偏重亞硫酸鈉溶液和苦味酸溶液的混合液，其組成為10 g/L的偏重亞硫酸鈉的水溶液，與40 g/L的苦味酸的乙醇溶液按11混合。一般侵蝕130秒（a solution of 1 g sodium metabisulfite in 100 water mixed with 4 g of picric acid dissolved in 100 of water, for 1-30 sec (LePERA, 1979; Lawson et al., 1980)）。（此段文字的來(lái)源，當(dāng)時(shí)沒(méi)有記錄，現(xiàn)在反復(fù)尋找，沒(méi)有結(jié)果）Lepera試劑在ASM的手冊(cè)（9）中沒(méi)有體現(xiàn)，檢索無(wú)結(jié)果；比較令人意外。因?yàn)閲?guó)內(nèi)TRIP鋼的研究涉及Lepera試劑的較多，在ASM的手冊(cè)（9）中，TRIP鋼所使用的試劑是：2% nital etch、4% picral etch。在下面這篇文章（作者：Y Sakuma - 1991 - 被引用次數(shù)：98）中，有一篇參考文獻(xiàn)，26，Metallurgical and Materials Transactions A Volume 22, Number 2, 489-498, 1991Mechanical properties and retained austenite in intercritically heat-treated bainite-transformed steel and their variation with Si and Mn additions Yasuharu Sakuma, Osamu Matsumura and Hiroshi Takechi26 S. Bandoh, O. Matsumura, and Y. Sakuma: Trans. Iron Steel Inst. Jpn., 1988, vol. 28, pp. 569-74.文章中涉及26的說(shuō)：Optical microscopy measurements were made on the specimens prepared by the tint-etching method, with a solution of 4 pct HNO3 + 7 pct (NO2)3CtH2OH + saturated Na2S203, 26。 在下面這篇文章（作者：E Girault - 1998 - 被引用次數(shù)：89）中，有部分源自F.S. LePera的文章中的描述；在得不到原文的情況下，看看最基本的內(nèi)容也不錯(cuò)。Materials CharacterizationVolume 40, Issue 2, February 1998, Pages 111-118Metallographic Methods for Revealing the Multiphase Microstructure of TRIP-Assisted SteelsE. Girault, P. Jacques, Ph. Harlet, K. Mols, J. Van Humbeeck, E. Aernoudt and F. Delannay 在韓波的貝氏體鋼彩色金相研究中的參考文獻(xiàn)，也提到了這篇文章，不過(guò)，書寫的“刊物”、“頁(yè)數(shù)”有關(guān)信息較為奇怪：1 Girault E, Jacques P, Harlet P, et al. Metallographic methods for revea ling the multiphase microstructure of TRIP-assisted steels J. Elsevier Science, 1998, 40（2）：111-112. 鄒宏輝的Si-Mn系TRIP鋼顯微組織研究中將此文作為參考文獻(xiàn)時(shí)是正確的；微有瑕疵的是：沒(méi)有標(biāo)注“期數(shù)”。4 Girault E, Jacques P, et al. Metallographic methods for revealing the multiphase microstructure of TRIP-assisted steelsJ. Materials Characterization. 1998,40:111118.貝氏體鋼彩色金相研究中還有一個(gè)參考文獻(xiàn)比較奇怪，這篇文章并沒(méi)有提到有關(guān)LePera reagent的有關(guān)信息；而作為參考文獻(xiàn)的目的何在，令人疑惑。就是： 2 張珣. 彩色金相在電力系統(tǒng)的應(yīng)用 J . 安徽電力職工大學(xué)學(xué)報(bào),2002, 7 (1) : 122.F.S. LePera首創(chuàng)的試劑，似乎有2個(gè)文獻(xiàn)來(lái)源，請(qǐng)看下面的檢索：Improved etching technique for the determination of percent martensite in high-strength dual-phase steels Metallography Volume 12, Issue 3, September 1979, Pages 263-268F.S. LePeraAbstractAn improved metallographic etchant and technique for delineating the various constituents in high-strength dual-phase steels has been developed as a result of the need for increased contrast when using electronic image analysis equipment. With an etchant consisting of a 1% aqueous solution of sodium metabisulfite (Na2S2O5) and 4% picric acid (C6H2(NO2)3OH) in ethyl alcohol, martensitic grains appear white, bainite appears black, ferrite appears tan, and in most cases, the grain boundaries are not strongly etched. Consequently, accurate measurements of the amount of martensite and bainite can be made using electronic image analysis equipment.Improved Etching Technique to Emphasize Martensite and Bainite in High-Strength Dual-Phase SteelLePera, F SJ. Met. Vol. 32, No. 3, pp. 38-39. Mar. 1980Many etchants based on sodium metabisulfite were tried in National Steels Research Laboratory on Cr-bearing dual-phase steels, but most failed to differentiate martensite from bainite. However, excellent results were obtained from a mixture of 1% sodium metabisulfite (Na2S2O5) in distilled water and 4% picric acid C6H2(NO)3OH in ethyl alcohol (either specially denatured alcohol S.D.A. 32, or completely denatured alcohol S.D.A. 1) in a 1:1 volume ratio. With this etchant, martensite appears white, bainite appears black, ferrite appears tan, and, in most cases, grain boundaries are not strongly etched.-AAImproved Etching Technique to Emphasize Martensite and Bainite in High-Strength Dual-Phase Steel里面的段落（源自Metallographic Methods for Revealing the Multiphase Microstructure of TRIP-Assisted Steels）：The specimen is embedded in an acrylic resin that stiffens at room temperature. The classical grinding and polishing stages are performed at least down to the use of 1m diamond paste. It is essential that the sample be freshly polished before etching to prevent any risk of preoxidation of the surface. After the last sequence of polishing, the specimen is rinsed with distilled water, cleaned with a soapy-water-soaked cloth, rinsed again, and flushed with ethanol. It is then dried under a warm air flow. This operation must be repeated several times to eliminate any trace of lubricant or impurities from the last polishing step.The etchant is a mixture of two pristine solutions whose compositions are given in Table 2. Volumes of 30 2 ml of reagent 1 and 30 2 ml of reagent 2 are poured into two different beakers. Just before the etching is started, the solutions are mixed in a small crystallizing vessel. The specimen is held vertically with a small tong and immediately immersed in the mix. It is given a permanent oscillation during the whole etching time, which lasts between 10 and 20 s, depending on the steel composition. After etching, the specimen surface is immediately flushed with ethanol and blown dry under a cool air flow. This step is repeated a few times to ensure that no etchant remains on the specimen. The specimen is finally observed with a microscope equipped with a high-brightness halogen lamp.Table 2 Composition of the SolutionsReagent 1 Reagent 21 g Na2S2O5 4g dry picric acid100 mL distilled H2O 100mL ethanol鄒宏輝的Si-Mn系TRIP鋼顯微組織研究中，有改進(jìn)的LePera reagent。表3腐蝕劑中兩種溶液的濃度試劑適用試樣溶質(zhì)溶劑1A、C1g Na2S2O580mL蒸餾水2B1g Na2S2O560mL蒸餾水3A、B、C1g苦味酸(干燥)40mL乙醇腐蝕劑的配制根據(jù)試樣化學(xué)成分,按表3配制偏重亞硫酸鈉溶液和苦味酸溶液。腐蝕時(shí),將偏重亞硫酸鈉溶液和苦味酸溶液混合(A、C鋼需將溶液1和溶液3混合,B鋼將溶液2與溶液3混合),體積比為11,攪拌均勻。然后將試樣浸入腐蝕液中侵蝕1824s,使腐蝕面泛出藍(lán)橙般的光澤。 超高強(qiáng)度船體鋼中馬氏體/奧氏體的演變一文，對(duì)于LePera試劑的著色效果，也有比較感性的介紹。在Y. D. PARK的Retained Austenite as a Hydrogen Trap in Steel Welds中，提到LePeras reagent時(shí)說(shuō)：Specimens for optical microscopy were prepared by mechanical polishing through 0.05-m alumina. Super duplex stainless steels were electrolytically etched for 5 to 20 s with 10% oxalic acid. LePeras reagent (Refs. 7, 8) was used to etch the HSLA steel weld deposits for optical microscopy. This etching method is based on sodium metabisulfite mixed with picric acid. The retained austenite and untempered martensite (or MA constituent) was identified with contrast enhancement resulting from LePeras reagent, which was a fresh solution of 4% picric acid in ethanol mixed with a 1% solution of sodium metabisulfite in distilled water in a 1:2 volume ratio.7. Iino, M. 1998. Evaluation of hydrogentrap binding enthalpy II. Met. Tr a n s . 2 9 A : 10171021.8. Le Pera, F. S. 1980. Improved etching technique to emphasize martensite and bainite in high-strength dual-phase steel. J. Met. 32(3): 3839.因此，兩種基礎(chǔ)試劑的混合配置配置比例也有不同的理解（常見(jiàn)識(shí)1：1）。關(guān)于：modified LePera reagent，在METAL 2009 19. 21. 5. 2009, Hradec nad Moravic，上的Katarna Burikov，Gejza Rosenberg的文章QUANTIFICATION OF MICROSTRUCTURAL PARAMETER FERRITIC-MARTENSITE DUAL PHASE STEEL BY IMAGE ANALYSIS中，終于涉及到了S. Bandoh的“modified LePera reagent”。同時(shí)，有了S. Bandoh完整的文獻(xiàn)名稱：8 Bandoh, S., Matsumura, O., Sakuma, Y.: An improved tint etching method for high strength steel sheets with mixed microstructures. Transactions ISIJ, 1988, Vol. 28, p. 569-574, Bandoh侵蝕劑配置：Solution A: 7 g Na2S2O5, 100 ml H2OSolution B: 5 g picric acid,100 ml C2H5OHSolution C: 4 ml HNO3, 95 ml C2H5OHFerrite is blue, martensiteand austenite is yellow,bainit is brown后來(lái)，又檢索到S. Bandoh的文章的Abstract：An improved tint etching method was developed to obtain a quantitative measure of the microstructure of high strength steel sheets with a mixed structure. The procedures of etching are presented with typical examples. The present method reveals ferrite in blue, martensite and retained austenite in light yellow, and bainite in brown. Each constituent is identified by electron microscopic observations of the same area on etched microstructure. The different colors are analyzed to be a result of difference in the thickness of etched films by means of Auger spectroscopy. The new method is combined with image analysis to determine quantitatively the fraction and morphology of microconstituents.Keywords:metallography, optical microscopy, etching method, cold-rolled steel, composite structure（Transactions of the Iron and Steel Institute of Japan；Vol.28 , No.7(1988)pp.569-574）（S. Bandoh, O. Matsumura and Y. Sakuma: Trans. Iron Steel Inst. Jpn., 28 (1988), 569）關(guān)于“The LePera techniques”查閱到的最為詳細(xì)的介紹是：FUNDAMENTAL STUDY OF PHASE TRANSFORMATIONS IN Si-Al TRIP STEELS（很幸運(yùn)，有下載的地址：/ETD/available/etd-