带有彩色照片的层压板，显示奥氏体不锈钢管内部的着色程度，以及背衬保护气体中氧气含量的增加。适合作为指定工具和目视检查指南。

Laminated sheet with color photograph showing degrees of coloration on the inside of an austenitic stainless steel tube with increasing amount of oxygen in the backing shielding gas. Suitable as a specifying tool and visual examination guide.