protectiveadj.保护的；防卫的protective diet保护饮食,防卫性饮食protective wall防风墙protective form防护形式protective coat保护敷层,保护层protective ring护环protective film保护膜protective drug[放射]防护药, [放射]保护药protective zone安全区,防护区protective fuse保护熔线protective cowl保护性罩

1. The PQR shall include the composition and flow rate of the shielding and inert gas backing, when used.
   焊接工艺评定记录单上应包括封底焊时所用的惰性保护气体组成成分和流率。