{"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":"liga-20-vs-904l","status":"publish","type":"post","link":"https:\/\/www.nickelcasting.com\/pt\/liga-20-vs-904l\/","title":{"rendered":"Liga 20 vs 904L: Resist\u00eancia ao \u00e1cido sulf\u00farico"},"content":{"rendered":"

No dom\u00ednio dos a\u00e7os inoxid\u00e1veis austen\u00edticos de elevado desempenho, a escolha entre a Liga 20 (UNS N08020) e a 904L (UNS N08904) define frequentemente a longevidade do equipamento industrial cr\u00edtico. Embora ambas as ligas tenham sido concebidas para colmatar a lacuna entre o a\u00e7o inoxid\u00e1vel 316L padr\u00e3o e as superligas de alto custo \u00e0 base de n\u00edquel, ocupam nichos distintos em termos de resist\u00eancia \u00e0 corros\u00e3o, particularmente em ambientes \u00e1cidos.<\/p>\n

\"\"<\/p>\n

Compara\u00e7\u00e3o entre a liga 20 e a 904L: Nuances qu\u00edmicas e f\u00edsicas<\/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

Em contrapartida, o 904L \u00e9 um a\u00e7o inoxid\u00e1vel austen\u00edtico de alta liga com um teor de n\u00edquel de cerca de 25%. Embora tamb\u00e9m contenha cobre para aumentar a resist\u00eancia a \u00e1cidos redutores fortes, foi desenvolvido principalmente para resistir \u00e0 corros\u00e3o por picadas e fendas em ambientes de \u00e1cido sulf\u00farico dilu\u00eddo e \u00e1cido fosf\u00f3rico.<\/p>\n

Tabela de especifica\u00e7\u00f5es t\u00e9cnicas<\/h3>\n\n\n\n\n\n\n\n\n\n\n
Im\u00f3veis<\/td>\nLiga 20 (UNS N08020)<\/td>\n904L (UNS N08904)<\/td>\n<\/tr>\n<\/thead>\n
N\u00edquel (Ni)<\/td>\n32,5% - 35,0%<\/td>\n23.0% - 28.0%<\/td>\n<\/tr>\n
Cr\u00f3mio (Cr)<\/td>\n19.0% - 21.0%<\/td>\n19.0% - 23.0%<\/td>\n<\/tr>\n
Molibd\u00e9nio (Mo)<\/td>\n2.0% - 3.0%<\/td>\n4.0% - 5.0%<\/td>\n<\/tr>\n
Cobre (Cu)<\/td>\n3.0% - 4.0%<\/td>\n1.0% - 2.0%<\/td>\n<\/tr>\n
Valor PREN<\/td>\n~24 – 26<\/td>\n~34 – 36<\/td>\n<\/tr>\n
Resist\u00eancia ao escoamento<\/td>\n35.000 psi (241 MPa)<\/td>\n31.000 psi (215 MPa)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Liga 20 vs 904L: Como escolher o material correto<\/h2>\n

Ao decidir Liga 20 vs 904L: como escolher, o fator principal \u00e9 a natureza espec\u00edfica do meio corrosivo.<\/p>\n

    \n
  1. \n

    Concentra\u00e7\u00e3o de cloreto vs. concentra\u00e7\u00e3o de \u00e1cido: Se a sua aplica\u00e7\u00e3o envolver concentra\u00e7\u00f5es elevadas de cloreto em que a corros\u00e3o por picadas \u00e9 a principal preocupa\u00e7\u00e3o, o 904L \u00e9 frequentemente a escolha superior devido ao seu teor mais elevado de molibd\u00e9nio e ao n\u00famero equivalente de resist\u00eancia \u00e0 corros\u00e3o por picadas (PREN) mais elevado.<\/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

    Efici\u00eancia de custos: Geralmente, o 904L \u00e9 mais econ\u00f3mico para o manuseamento de produtos qu\u00edmicos de uso geral, enquanto a liga 20 \u00e9 um investimento especializado para pontos de ebuli\u00e7\u00e3o de \u00e1cidos agressivos e tubos de permutadores de calor.<\/p>\n<\/li>\n<\/ol>\n

    \"\"<\/h2>\n

    Liga 20 vs 904L: Estrat\u00e9gias de sele\u00e7\u00e3o de instala\u00e7\u00f5es qu\u00edmicas<\/h2>\n

    No contexto da sele\u00e7\u00e3o da liga 20 vs 904L para instala\u00e7\u00f5es qu\u00edmicas, os engenheiros devem considerar o custo total do ciclo de vida. Nas instala\u00e7\u00f5es de processamento qu\u00edmico, a liga 20 \u00e9 o material preferido para tanques de decapagem, tanques de mistura e permutadores de calor que lidam com concentra\u00e7\u00f5es de \u00e1cido sulf\u00farico at\u00e9 95% a temperaturas elevadas.<\/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

    Perguntas e respostas relacionadas<\/h3>\n

    Q1: A liga 20 pode ser utilizada em aplica\u00e7\u00f5es de \u00e1gua do mar? A1: Embora a liga 20 tenha uma resist\u00eancia decente, a 904L \u00e9 geralmente preferida para ambientes de \u00e1gua do mar ou com elevado teor de cloretos devido ao seu PREN mais elevado (34-36), que oferece uma melhor prote\u00e7\u00e3o contra a corros\u00e3o.<\/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

    P3: Que liga \u00e9 mais f\u00e1cil de soldar numa f\u00e1brica de produtos qu\u00edmicos? R3: Ambas apresentam boa soldabilidade utilizando m\u00e9todos comuns como TIG ou MIG. No entanto, a estabiliza\u00e7\u00e3o de ni\u00f3bio da Liga 20 torna-a ligeiramente mais resistente \u00e0 precipita\u00e7\u00e3o de carbonetos na zona afetada pelo calor (HAZ) em compara\u00e7\u00e3o com a 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\/pt\/wp-json\/wp\/v2\/posts\/2457","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/comments?post=2457"}],"version-history":[{"count":1,"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/posts\/2457\/revisions"}],"predecessor-version":[{"id":2460,"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/posts\/2457\/revisions\/2460"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/media\/2458"}],"wp:attachment":[{"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/media?parent=2457"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/categories?post=2457"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nickelcasting.com\/pt\/wp-json\/wp\/v2\/tags?post=2457"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}