{"id":1169,"date":"2026-05-08T20:48:42","date_gmt":"2026-05-09T00:48:42","guid":{"rendered":"https:\/\/www.songhaiflange.com\/?p=1169"},"modified":"2026-05-08T20:48:42","modified_gmt":"2026-05-09T00:48:42","slug":"gb-t-226-2015-test-method-for-steel-macrostructure-and-defect-by-etching-english-translation","status":"publish","type":"post","link":"https:\/\/www.songhaiflange.com\/it\/2026\/05\/08\/gb-t-226-2015-test-method-for-steel-macrostructure-and-defect-by-etching-english-translation\/","title":{"rendered":"GB\/T 226-2015 Test Method for Steel Macrostructure and Defect by Etching (English Translation)"},"content":{"rendered":"<h1>GB\/T 226-2015 Test Method for Macrostructure and Defect of Steel by Etching<\/h1>\n<h2>Standard Information<\/h2>\n<ul>\n<li><strong>Standard Number:<\/strong> GB\/T 226-2015<\/li>\n<li><strong>Replaces:<\/strong> GB\/T 226-1991<\/li>\n<li><strong>Release Date:<\/strong> September 11, 2015<\/li>\n<li><strong>Implementation Date:<\/strong> June 1, 2016<\/li>\n<li><strong>Proposed by:<\/strong> China Iron and Steel Association<\/li>\n<li><strong>Managed by:<\/strong> National Steel Standardization Technical Committee (SAC\/TC 183)<\/li>\n<\/ul>\n<h2>Scope<\/h2>\n<p>This standard specifies three test methods for examining macrostructure and defects in steel:<\/p>\n<ul>\n<li><strong>Hot Acid Etching Method<\/strong><\/li>\n<li><strong>Cold Acid Etching Method<\/strong> (including dendrite etching)<\/li>\n<li><strong>Electrolytic Etching Method<\/strong><\/li>\n<\/ul>\n<p>This standard applies to acid etching inspection of steel macrostructure and defects. Other materials may be tested by reference to this standard.<\/p>\n<h2>Key Technical Requirements<\/h2>\n<h3>Sample Preparation<\/h3>\n<ul>\n<li><strong>Sample thickness:<\/strong> Generally 20-30 mm<\/li>\n<li><strong>Longitudinal sample length:<\/strong> Generally 1.5 times the side length or diameter<\/li>\n<li><strong>Minimum distance from cutting surface:<\/strong>\n<ul>\n<li>Hot saw cutting: \u226520 mm<\/li>\n<li>Cold saw cutting: \u226510 mm<\/li>\n<li>Flame cutting: \u226525 mm<\/li>\n<\/ul>\n<\/li>\n<li><strong>Surface roughness (Ra) requirements:<\/strong>\n<ul>\n<li>Hot acid etching: \u22641.6 \u03bcm<\/li>\n<li>Cold acid etching: \u22640.8 \u03bcm (dendrite etching: \u22640.025 \u03bcm after polishing)<\/li>\n<li>Electrolytic etching: \u22641.6 \u03bcm<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Hot Acid Etching Method (Recommended for Arbitration)<\/h3>\n<p>Recommended etching solutions vary by steel type:<\/p>\n<ul>\n<li><strong>Carbon\/Alloy structural steel, tool steel, stainless steel:<\/strong> 1:1 hydrochloric acid solution, 70-80\u00b0C, 5-40 min<\/li>\n<li><strong>Austenitic stainless steel\/heat-resistant steel:<\/strong> HCl 10 parts + HNO\u2083 1 part + water 10 parts, 70-80\u00b0C<\/li>\n<li><strong>High-speed tool steel:<\/strong> HCl 38 parts + H\u2082SO\u2084 12 parts + water 50 parts, 60-80\u00b0C<\/li>\n<\/ul>\n<h3>Cold Acid Etching Method<\/h3>\n<p>13 types of cold etching solutions are specified for different steel types including carbon steel, alloy steel, stainless steel, nickel-based alloys, and precision alloys.<\/p>\n<h3>Electrolytic Etching Method<\/h3>\n<ul>\n<li><strong>AC Electrolytic:<\/strong> 15-30% HCl solution, voltage \u226436V, current \u2264400A, 5-30 min<\/li>\n<li><strong>DC Electrolytic:<\/strong> Sample as anode, HCl solution with optional boric acid, current density varies by sample area<\/li>\n<\/ul>\n<h2>Result Documentation<\/h2>\n<ul>\n<li>Hot\/Cold\/Electrolytic etching results: Optical photography or digital imaging<\/li>\n<li>Dendrite etching results: Scanning imaging (resolution >1000 dpi)<\/li>\n<\/ul>\n<h2>Sample Preservation Methods<\/h2>\n<ul>\n<li><strong>Neutralization:<\/strong> Soak in 10% ammonia alcohol solution, rinse with hot water, dry<\/li>\n<li><strong>Passivation:<\/strong> Immerse in concentrated nitric acid (~5 seconds), rinse, dry<\/li>\n<li><strong>Coating protection:<\/strong> Apply varnish or plastic film<\/li>\n<\/ul>\n<h2>Environmental Safety<\/h2>\n<p>Waste acid must be treated according to GB 8978-1996 Class II pollutant discharge regulations.<\/p>\n<h2>Test Report Requirements<\/h2>\n<p>The inspection report shall include:<\/p>\n<ol>\n<li>Client unit<\/li>\n<li>Steel grade<\/li>\n<li>Melting (batch) number<\/li>\n<li>Sample number<\/li>\n<li>Sample cutting direction<\/li>\n<li>Test method<\/li>\n<li>Test results<\/li>\n<li>Inspector and report date<\/li>\n<\/ol>\n<h2>Download Original Standard<\/h2>\n<p><a href=\"https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/05\/GBT_226-2015_Steel_Macrostructure_Etching_Test.pdf\" target=\"_blank\" download>\ud83d\udcc4 Download Original PDF (GB\/T 226-2015 Chinese Standard)<\/a><\/p>\n<p><embed src=\"https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/05\/GBT_226-2015_Steel_Macrostructure_Etching_Test.pdf\" type=\"application\/pdf\" width=\"100%\" height=\"600px\" \/><\/p>\n<p><em>Note: This is an English translation summary of GB\/T 226-2015. For official purposes, please refer to the original Chinese standard document.<\/em><\/p>","protected":false},"excerpt":{"rendered":"<p>GB\/T 226-2015 Test Method for Macrostructure and Defect of Steel by Etching Standard Information Standard Number: GB\/T 226-2015 Replaces: GB\/T 226-1991 Release Date: September 11, 2015 Implementation Date: June 1, 2016 Proposed by: China Iron and Steel Association Managed by: National Steel Standardization Technical Committee (SAC\/TC 183) Scope This standard specifies three test methods for [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1169","post","type-post","status-publish","format-standard","hentry","category-blog"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/posts\/1169","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/comments?post=1169"}],"version-history":[{"count":1,"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/posts\/1169\/revisions"}],"predecessor-version":[{"id":1170,"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/posts\/1169\/revisions\/1170"}],"wp:attachment":[{"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/media?parent=1169"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/categories?post=1169"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.songhaiflange.com\/it\/wp-json\/wp\/v2\/tags?post=1169"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}