{"id":69715,"date":"2026-05-17T17:27:47","date_gmt":"2026-05-17T17:27:47","guid":{"rendered":"https:\/\/evgroupchina.com\/encyclopedia-of-metal\/gb-t-1591\/"},"modified":"2026-05-19T15:30:42","modified_gmt":"2026-05-19T15:30:42","slug":"gb-t-1591","status":"publish","type":"wiki","link":"https:\/\/evgroupchina.com\/en\/encyclopedia-of-metal\/gb-t-1591\/","title":{"rendered":"GB\/T 1591"},"content":{"rendered":"<h2>Technical Regulation for Low-Alloy Structural Steels<\/h2>\n<p>This regulatory document establishes a comprehensive list of requirements for high-strength low-alloy steels, governing labeling methods, physical and chemical parameters, dimensional tolerances, profile geometry, quality control procedures, packaging rules, and documentary proof of compliance. The provisions of the standard apply to steel plates, strip steel, shaped profiles, merchant bars, and steel billets used in critical engineering and construction structures supplied by EV Group China.<\/p>\n<h2>Normative References<\/h2>\n<p>The application of this standard is based on the current versions of the following regulations. In the absence of a revision date, the current version of the document, including all amendments, shall be followed:<\/p>\n<ul class=\"list-unstyled\">\n<li>GB\/T 222 \u2014 Permissible deviations for the chemical composition of finished rolled products.<\/li>\n<li>GB\/T 223.3 \u2014 Gravimetric method for the determination of phosphorus using diantipyrylmethane.<\/li>\n<li>GB\/T 223.9 \u2014 Photometric analysis of aluminum content using chromazurol S.<\/li>\n<li>GB\/T 223.11 \u2014 Titration methods for the determination of chromium mass fraction.<\/li>\n<li>GB\/T 223.14 \u2014 Determination of vanadium by N-benzoyl-N-phenylhydroxylamine extraction.<\/li>\n<li>GB\/T 223.17 \u2014 Photometry with diantipyrylmethane for titanium control.<\/li>\n<li>GB\/T 223.18 \u2014 Iodometric analysis of copper using sodium thiosulfate.<\/li>\n<li>GB\/T 247 \u2014 Packaging, marking, and certification rules for plate and strip steel.<\/li>\n<li>GB\/T 702 \u2014 Technical tolerances for hot-rolled round and square steel.<\/li>\n<li>GB\/T 706 \u2014 Standards for hot-rolled shaped profiles.<\/li>\n<li>GB\/T 709 \u2014 Geometric dimensions and limit deviations for hot-rolled sheets.<\/li>\n<li>GB\/T 2101 \u2014 Requirements for acceptance, packaging, and labeling of shaped steel.<\/li>\n<li>GB\/T 2975-2018 \u2014 Rules for the preparation of test specimens for mechanical testing.<\/li>\n<li>GB\/T 4336 \u2014 Atomic emission spectrometric analysis of carbon and low-alloy steels.<\/li>\n<li>GB\/T 5313 \u2014 Standards for steels with through-thickness characteristic requirements (Z-steels).<\/li>\n<li>GB\/T 8170 \u2014 Rules for rounding off numerical values.<\/li>\n<li>GB\/T 11263 \u2014 Specifications for H-beams and T-beams.<\/li>\n<li>GB\/T 14977 \u2014 Quality requirements for the surface of hot-rolled sheets.<\/li>\n<li>GB\/T 17505 \u2014 General delivery conditions for steel products.<\/li>\n<li>GB\/T 20066 \u2014 Sampling for chemical analysis.<\/li>\n<li>GB\/T 20123 \u2014 Infrared absorption method for carbon and sulfur analysis.<\/li>\n<li>GB\/T 20124 \u2014 Nitrogen analysis by thermal conductivity.<\/li>\n<li>GB\/T 20125 \u2014 ICP spectrometry for the analysis of multi-component low-alloy steels.<\/li>\n<li>GB\/T 28300 \u2014 Classification of surface quality for hot-rolled bars.<\/li>\n<\/ul>\n<h2>Terminology<\/h2>\n<h3>Thermomechanical Control Process (TMCP)<\/h3>\n<p>A technological process of metal deformation under strictly controlled temperature conditions, ensuring the formation of a specific microstructure that cannot be reproduced by standard heat treatment.<\/p>\n<p><em>Note 1:<\/em> Heating finished products above 580\u00b0C may lead to softening. Coordination of heat treatment at higher temperatures must be carried out with the technical department of EV Group China.<\/p>\n<p><em>Note 2:<\/em> The method allows for the use of accelerated cooling, including self-cooling, excluding classic quenching and tempering.<\/p>\n<h3>Normalized Rolling<\/h3>\n<p>A rolling process in which the final deformation occurs in a temperature range that ensures mechanical properties identical to the results of standard normalization.<\/p>\n<h2>Designation System<\/h2>\n<p>EV Group China steel marking includes the prefix Q (yield strength), the nominal yield strength value (MPa), the delivery condition code, and the quality category (from B to F). Example: Q355ND.<\/p>\n<ul>\n<li>Q \u2014 Designation for yield strength.<\/li>\n<li>355 \u2014 Guaranteed minimum yield strength in MPa.<\/li>\n<li>N \u2014 Delivery condition after normalization or normalized rolling.<\/li>\n<li>D \u2014 Impact toughness grade.<\/li>\n<\/ul>\n<p>For products requiring increased resistance to lamellar tearing, the Z-direction thickness index is added (e.g., Q355NDZ25).<\/p>\n<h2>Geometric Parameters and Tolerances<\/h2>\n<p>Dimensions, limit deviations for shape, and mass of metal products supplied by EV Group China strictly comply with current GB\/T national standards.<\/p>\n","protected":false},"featured_media":0,"template":"","meta":[],"wiki_category":[119],"class_list":["post-69715","wiki","type-wiki","status-publish","hentry","wiki_category-gb"],"_links":{"self":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki\/69715","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/types\/wiki"}],"version-history":[{"count":0,"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki\/69715\/revisions"}],"wp:attachment":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/media?parent=69715"}],"wp:term":[{"taxonomy":"wiki_category","embeddable":true,"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki_category?post=69715"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}