内焰    internal flame

层间温度    interpass temperature

胡须    intrusion

逆变式电阻焊机    inverter type resistance welding machine

逆变式焊接电源    inverter welding power source

氧化铁型焊条    iron oxide type electrode/ high iron oxide type electrode

铁粉焊条    iron powder electrode

烙铁钎焊    iron soldering