6、fold脚手架 scaffolding脚手架工程词汇质量合格证书 certificationoffitness原材料 raw material底板bottomplate垫层cushion侧壁sidewall中心线centerline条形基础stripfooting附件accessories型钢profilesteel钢板steelplate熔渣slag飞溅weldingspatter定位焊tacking引弧generatingofarc熄弧quenchingofarc焊道weldingbead坡口beve