GB/T699-2015《优质碳素结构钢》是中国国家标准，规定了优质碳素结构钢的分类、技术要求、试验方法、检验规则、包装、标志和质量证明书等内容。该标准适用于制造机械零件和工程结构用优质碳素结构钢的热轧和锻制钢材。标准中详细列出了不同牌号钢材的化学成分、力学性能、工艺性能等技术指标，确保钢材的质量和性能满足工业应用需求。TheGB/T699-2015"QualityCarbonStructuralSteels"isaChinesenationalstandardthatspecifiestheclassification,technicalrequirements,testmethods,inspectionrules,packaging,marking,andqualitycertificatesforqualitycarbonstructuralsteels.Thisstandardappliestohot-rolledandforgedqualitycarbonstructuralsteelsusedinthemanufactureofmechanicalpartsandengineeringstructures.Itprovidesdetailedtechnicalrequirements,includingchemicalcomposition,mechanicalproperties,andprocessperformancefordifferentsteelgrades,ensuringthequalityandperformanceofthesteelmeetindustrialapplicationdemands.该标准的中英文版便于国内外企业和技术人员参考使用，促进国际贸易和技术交流。TheChinese-Englishversionofthisstandardfacilitatesreferencefordomesticandinternationalenterprisesandtechnicalpersonnel,promotinginternationaltradeandtechnicalexchange.
