First of all, this protection is invulnerable, some workpiece has long and thin bending holes, or narrow and thin blind holes, often oil is difficult to rust, if the vapor phase rust inhibitor can easily complete rust measures. In fact, the vapor phase antirust agent is a kind of active RP material, as long as the sealing environment permits, RP agent is still in, the RP effect can continue. Therefore, its RP protection period is very long, it is commonly used in military weapons , the longest RP period can be up to 12-20 years. Its use of protection and removal is very convenient, as long as the workpiece is put together with it, coupled with plastic bags and other sealing to complete the PRESERVATION, when removing the sealing bag, take out can be used. In recent years, like the export of mechanical and electrical products of European countries, the other party often requires the use of oil-free rust prevention, because rust prevention oil is eventually turned into sewage, which will cause pollution to the importing country. Therefore, the use and dosage of VAPOR phase antirust agent will be more and more large, it can be foreseen that in the near future, vapor phase RP agent will become one of the main RP materials of steel.