ボルト, リベツト, パイプおよび熔接部の腐蝕試驗

抄録

Before galvanized, bolts and pipes are usually steeped in 10% H_2SO_4 for cleaning. In Fig's 1 and 2 are shown examples of bolts and pipes cracked by corrosion during the cleaning process. In this paper are given the explanations on the results of their corrosion tests in 10% H_2SO_4. The results obatained are as follows; (1) There exist many bolts which contain much sulphur segregation as shown in Fig.5. This fact explaines why bolts are apt to be corroded as shown in Fig.6. (2) Rivet-material seldom contains sulphur segregation except only in a few examples as shown in Fig.10. Therefrom we can infer that the rivet head corrosion often found in ships would be due to some other causes. (3) Pipe-materials, which contain more sulphur than other steels, are apt to be corroded and the corrosion degree is accelerated by plastic bending. (4) In their experiments, the authors could not detect any corrosion on welded parts even under stress condition.