IMPROVEMENT on DEGREASING PROPERTY of AUTOMOTIVE OUTER-PANEL in a PRETREATMENT PROCESS for AUTOMOTIVE BODY

摘要

In the study the following results were obtained. 1. Small amount of Boron in steel can diffuses to the steel surface and forms BN thin film by the reaction with nitrogen of the annealing atmosphere, which can cause no good degreased surface in the degreasing process of the carmaker. 2. By the proper control of the dew point of the annealing atmosphere, this phenomenon can be prevented.