焊缝看不见摸不着，却是整个结构的安全底线。一级、二级焊缝到底差在哪？Welds are invisible once painted, yet they are the safety baseline of the whole structure. What really separates Class 1 from Class 2 welds?
钢构质检中，焊缝是技术含量最高、也最容易被低价竞标牺牲的环节。
按 GB 50205 规范，焊缝分三个等级：一级焊缝 100% 超声波探伤，用于吊车梁受拉翼缘等关键部位；二级焊缝 20% 探伤，用于一般受力构件；三级焊缝做外观检查即可。出口项目按 ISO 17635 或 AWS D1.1 执行时分级逻辑类似。
客户最实用的验证方式：要求工厂提供焊工资质证书（关键岗位必须持证）与焊缝探伤报告，并在第三方验货时把探伤抽检列入检查清单。雄岚所有出口项目默认提供全套焊接质量文件。
In steel QC, welding is the most skill-intensive process — and the first one sacrificed in low bids.
Under GB 50205, welds are classified in three grades: Class 1 gets 100% ultrasonic testing (critical parts such as crane girder tension flanges); Class 2 gets 20% UT for standard members; Class 3 requires visual inspection only. Export projects under ISO 17635 or AWS D1.1 follow similar logic.
The most practical verification for buyers: ask the factory for welder qualification certificates (key positions must be certified) and UT reports, and include weld sampling in any third-party inspection checklist. All Xionglan export projects ship with complete welding quality documentation.
上海雄岚钢结构 · 出口 60+ 国家 · EN 1090 CE 认证 · 24 小时内工程师回复
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