دانلود ترجمه مقاله کاربرد روش الكتروشيميایی جهت ارزيابی مقاومت در برابر خوردگی فولاد زنگ نزن دولايه

• فهرست مطالب:

چكيده
۱ مقدمه
۲ رويه آزمايشي
۳ نتايج و بحث
۴ نتيجه گيري

• بخشی از ترجمه:

بر اساس نتايج حاصله، فولاد ضد زنگ دولايه را مي توان از پودرهاي فولاد ضد زنگ (آستنيتي،فريتي و مارتنزيتي) با افزودن سادۀ عناصر منفرد از طريق يك پروسۀ صنعتي معمولي در خلاء بدست آورد.فولادهاي ساخته شده داراي ساختار آستنيتي-فريتي با آرايش منظم هر دو فازهستند كه رسوبات ناش از سرمايش سريع بعد از زينتر در هيچ يك از دو فاز وجود ندارد.ريزساختار فولاد دولايۀ زينتر مبني بر پودرهاي پايۀ X2CrNiMo17-12-2 (AISI 316L) و XCr17 (AISI 430L) با محتوي برابر در مقايسه با فولادهاي حاصل از افزايش پودرهاي عنصري با پودر پايۀ مارتنزيتي XCr13 (AISI 410L) كه دانه هاي آستنيتي و فريتي كاملا باهم تركيب مي شوند، داراي دانه هاي خشن تراست.
مطابق با نتايج آزمون خوردگي ، فولادهاي دولايۀ زينتر كه جديدا ايجاد شده اند، مقاومت در برابر خوردگي خوب به خاطر ۱Mمحلول NaCl از ويژگيهاي آنها است.مقاومت در برابر خوردگي فولادهاي ضدزنگ زينتر ارتباط زيادي با دانسيته و ريخت شناسي منفذ موجود در زيرساختار نيز دارند.بيشترين مقاومت در برابر خوردگي متخلخل در ۱M محلول NaCl برا تركيب داراي توازن تقربي فري و آستنيت موجود در ريزساختار بدست آمد و علاوه بر اين، نتايج بهتر به دليل تأثير زياد بيشترين دانسيته بر خواص خوردگي، براي ترگيبات مبني بر پودرهاي مارتنزيتي بدست آمد.
مزيت اصلي استفاده از فولادهاي ضدزنگ دولايۀ زينتر در مقايسه با مواد كارآوردۀ مشابه به خاطر مقاومت در برابر خوردگي پايين تراست.راه حل موجود توليد تعداد زيادي قطعه با هندسۀ پيچيده و اندازۀ كوچك توسط متالوژي پودرياست.بنابراين، استفاده از اين فولادها در صنعت اتومبيل امكان پذر و مقرون به صرفه است.

• بخشی از مقاله انگلیسی:

to their high mechanical properties and good corrosion resistance. According to profitability, high dimensional tolerance, shape reproducibility and energy saving the main receiver of parts produced by powder technology is automotive appliances industries. The powder metallurgy stainless steels, especially ferritic grades, have found applications in mounting brackets for the rear view mirrors, the tone wheels for the antilock brake systems and also in automotive exhaust applications like exhaust flanges and mounting unit of HEGOS [1-3]. The automotive market introduces newly designed sintered parts in large amounts in produced cars. Stainless steel is the preferred material for powder metal flanges because of its resistance to corrosion and oxidation. The fact that the powder metal parts can be made in high material densities for the optimum combination of properties has encouraged their use at biggest users of powder metal exhaust system flanges in the world. The usage of automobile parts manufactured by powder metallurgy in still weak in Europe [4] and Japan (Fig. 1), which is the reason of advanced researches on the sintered stainless steels especially easy to manufacture, cost effective and environmental friendly grades. Duplex stainless steels are the newest in the stainless steels family. They are characterized by a two-phase microstructure consisting of approximately equal amounts of ferrite and austenite. Duplex steels thus combine some of the features of the two major classes, austenitic and ferritic grades. Sintered duplex stainless steel seems to be very promising in those appliances what explain performed research in Europe [5÷۱۲]. Fig. 1 Parts weight in typical vehicle made by powder metallurgy. Pitting corrosion resistance in NaCl environment plays decisive rule in properties of stainless steels. Evaluations of electrochemical behaviour of sintered duplex steels using potentiodynamic polarization enable the determination of their properties in these conditions and make possible simulate real work conditions accelerated. In the field of powder metallurgy density highly influence the corrosion resistance due to electrolyte penetration to open porosity and corrosion proceed faster. In consequence of interconnected pores in the microstructure of sintered stainless steels, lower corrosion resistance is achieved [13-15]. This paper presents the results of researches carried out on the sintered duplex stainless steels obtained by mixing of elemental powders to an either martensitic or austenitic powder and their comparison with steel obtained trough mixing austenitic and ferritic powder in equal quantities. The work has been focused towards the evaluation of obtained microstructures and corrosion resistance in chloride containing environment. 2. Experimental procedure To produce sintered duplex stainless steel different compositions have been tested, using austenitic X2CrNiMo17-12- 2 (AISI 316L) and martensitic X6Cr13 (AISI 410L) (Fig. 2) as starting base water atomized powders of Hoganas Corporation with the characteristics presented in Table 1. Austenitic base powder X2CrNiMo 17-12-2 were mixed with addition of alloying elements powders such as Cr (in form of ferrochromium powder), Ni, Mo and Cu in the right quantity to obtain the chemical composition similar to biphasic one – mixtures A and B. Powder mixtures signed as C and D were produced starting from martensitic powder X6Cr13. Moreover, the ferritic stainless steel X6Cr17 powder has been mixed to austenitic stainless steel powder in the ratio of 1/1 in order to examine the microstructure derived after sintering (mixture E). In the preparation of powder mixtures, Schaeffler’s diagram was taken into consideration (Fig. 3). Although its proper application is in welding, it is possible to extend its use in the field of powder metallurgy. Thus CrE and NiE equivalents were obtained using formulas 1 and 2 respectively.

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