{"id":2457,"date":"2026-01-24T07:40:32","date_gmt":"2026-01-24T06:40:32","guid":{"rendered":"https:\/\/www.nickelcasting.com\/?p=2457"},"modified":"2026-01-30T03:00:38","modified_gmt":"2026-01-30T02:00:38","slug":"alloy-20-vs-904l","status":"publish","type":"post","link":"https:\/\/www.nickelcasting.com\/de\/alloy-20-vs-904l\/","title":{"rendered":"Legierung 20 vs. 904L: Schwefels\u00e4urebest\u00e4ndigkeit"},"content":{"rendered":"

Im Bereich der austenitischen Hochleistungsedelst\u00e4hle entscheidet die Wahl zwischen Alloy 20 (UNS N08020) und 904L (UNS N08904) oft \u00fcber die Langlebigkeit wichtiger Industrieanlagen. Beide Legierungen wurden entwickelt, um die L\u00fccke zwischen dem rostfreien Standardstahl 316L und den teuren Superlegierungen auf Nickelbasis zu schlie\u00dfen, und besetzen unterschiedliche Nischen in Bezug auf die Korrosionsbest\u00e4ndigkeit, insbesondere in sauren Umgebungen.<\/p>\n

\"\"<\/p>\n

Vergleich zwischen Legierung 20 und 904L: Chemische und physikalische Nuancen<\/h2>\n

Understanding the Alloy 20 vs 904L comparison begins with their chemical signatures. Alloy 20 is frequently classified as a “super-austenitic” stainless steel or a nickel alloy because of its high nickel content (approx. 35%). This high nickel concentration, combined with copper and molybdenum, provides exceptional resistance to sulfuric acid at various temperatures and concentrations.<\/p>\n

Im Gegensatz dazu ist 904L ein hochlegierter austenitischer rostfreier Stahl mit einem Nickelgehalt von etwa 25%. Er enth\u00e4lt zwar auch Kupfer, um die Best\u00e4ndigkeit gegen stark reduzierende S\u00e4uren zu erh\u00f6hen, wurde aber in erster Linie entwickelt, um Lochfra\u00df und Spaltkorrosion in verd\u00fcnnter Schwefels\u00e4ure und Phosphors\u00e4ure zu widerstehen.<\/p>\n

Tabelle der technischen Spezifikationen<\/h3>\n\n\n\n\n\n\n\n\n\n\n
Eigentum<\/td>\nLegierung 20 (UNS N08020)<\/td>\n904L (UNS N08904)<\/td>\n<\/tr>\n<\/thead>\n
Nickel (Ni)<\/td>\n32.5% - 35.0%<\/td>\n23.0% - 28.0%<\/td>\n<\/tr>\n
Chrom (Cr)<\/td>\n19.0% - 21.0%<\/td>\n19.0% - 23.0%<\/td>\n<\/tr>\n
Molybd\u00e4n (Mo)<\/td>\n2.0% - 3.0%<\/td>\n4.0% - 5.0%<\/td>\n<\/tr>\n
Kupfer (Cu)<\/td>\n3.0% - 4.0%<\/td>\n1.0% - 2.0%<\/td>\n<\/tr>\n
PREN-Wert<\/td>\n~24 – 26<\/td>\n~34 – 36<\/td>\n<\/tr>\n
Streckgrenze<\/td>\n35.000 psi (241 MPa)<\/td>\n31.000 psi (215 MPa)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Legierung 20 vs. 904L: Wie man das richtige Material w\u00e4hlt<\/h2>\n

Bei der Entscheidung zwischen Alloy 20 und 904L kommt es in erster Linie auf die Beschaffenheit des korrosiven Mediums an.<\/p>\n

    \n
  1. \n

    Chlorid vs. S\u00e4urekonzentration: Bei Anwendungen mit hohen Chloridkonzentrationen, bei denen Lochfra\u00df das Hauptproblem ist, ist 904L aufgrund seines h\u00f6heren Molybd\u00e4ngehalts und seiner h\u00f6heren Lochfra\u00dfbest\u00e4ndigkeits-\u00c4quivalenzzahl (PREN) oft die bessere Wahl.<\/p>\n<\/li>\n

  2. \n

    Sulfuric Acid Purity: Alloy 20 is the industry standard for “Sulfuric Acid Service.” It excels in 20% to 40% sulfuric acid concentrations where other steels fail. Its niobium (columbium) stabilization also prevents intergranular corrosion during welding.<\/p>\n<\/li>\n

  3. \n

    Kosteneffizienz: Im Allgemeinen ist 904L f\u00fcr den allgemeinen Umgang mit Chemikalien kosteng\u00fcnstiger, w\u00e4hrend Alloy 20 eine spezielle Investition f\u00fcr aggressive S\u00e4uresiedepunkte und W\u00e4rmetauscherrohre ist.<\/p>\n<\/li>\n<\/ol>\n

    \"\"<\/h2>\n

    Legierung 20 vs. 904L: Auswahlstrategien f\u00fcr chemische Anlagen<\/h2>\n

    Bei der Auswahl von Alloy 20 im Vergleich zu 904L f\u00fcr Chemieanlagen m\u00fcssen die Ingenieure die gesamten Lebenszykluskosten ber\u00fccksichtigen. In Chemieanlagen ist Alloy 20 das bevorzugte Material f\u00fcr Beiztanks, Mischtanks und W\u00e4rmetauscher, die mit Schwefels\u00e4urekonzentrationen von bis zu 95% bei erh\u00f6hten Temperaturen arbeiten.<\/p>\n

    Conversely, 904L is the go-to for flue-gas desulfurization (FGD) systems, pharmaceutical manufacturing, and paper pulp processing. It provides a robust defense against “warm sea water” and brackish water, making it ideal for coastal chemical facilities where external salt spray adds an extra layer of corrosive stress to the piping.<\/p>\n

    \n

    Verwandte Fragen und Antworten<\/h3>\n

    Q1: Kann Alloy 20 in Meerwasseranwendungen verwendet werden? A1: Obwohl Alloy 20 eine gute Best\u00e4ndigkeit aufweist, wird 904L aufgrund seiner h\u00f6heren PREN-Werte (34-36), die einen besseren Schutz gegen Lochfra\u00df bieten, im Allgemeinen f\u00fcr Meerwasser oder Umgebungen mit hohem Chloridgehalt bevorzugt.<\/p>\n

    Q2: Why is Alloy 20 called “The Carpenter 20” alloy? A2: It was originally developed by Carpenter Technology Corporation. Today, many manufacturers produce it under the UNS N08020 specification, but it remains the benchmark for sulfuric acid resistance.<\/p>\n

    F3: Welche Legierung ist in einem Chemiewerk leichter zu schwei\u00dfen? A3: Beide weisen eine gute Schwei\u00dfbarkeit mit g\u00e4ngigen Verfahren wie WIG oder MIG auf. Die Niobstabilisierung von Alloy 20 macht sie jedoch etwas widerstandsf\u00e4higer gegen Karbidausscheidungen in der W\u00e4rmeeinflusszone (WEZ) im Vergleich zu 904L.<\/p>","protected":false},"excerpt":{"rendered":"

    In the realm of high-performance austenitic stainless steels, the choice between Alloy 20 (UNS N08020) and 904L (UNS N08904) often defines the longevity of critical industrial equipment. While both alloys were engineered to bridge the gap between standard 316L stainless steel and high-cost nickel-based superalloys, they occupy distinct niches in corrosion resistance, particularly in acidic […]<\/p>","protected":false},"author":1,"featured_media":2458,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[3],"tags":[],"class_list":["post-2457","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"spectra_custom_meta":{"_edit_lock":["1769738438:1"],"_edit_last":["1"],"rank_math_seo_score":["69"],"rank_math_description":["A technical guide comparing Alloy 20 and 904L stainless steels. 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While both alloys were engineered to bridge the gap between standard 316L stainless steel and high-cost nickel-based superalloys, they occupy distinct niches in corrosion resistance, particularly in acidic…","_links":{"self":[{"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/posts\/2457","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/comments?post=2457"}],"version-history":[{"count":1,"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/posts\/2457\/revisions"}],"predecessor-version":[{"id":2460,"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/posts\/2457\/revisions\/2460"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/media\/2458"}],"wp:attachment":[{"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/media?parent=2457"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/categories?post=2457"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nickelcasting.com\/de\/wp-json\/wp\/v2\/tags?post=2457"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}