搜索a片网站簧片视频免费看|偷拍视频一区二区三区免费观看|一级片三级片播放器|www.91av视频在线观看|导航aV福利毛片一区二区|亚洲av91成人毛片美国片|国产AV一站成人超碰|A片视频福利精品爱视频|亚洲无码丝袜在线无码86|91无码精品字幕网av

JINGHONG

Weathering board

Weathering Steel can be exposed to the atmosphere without painting. It begins to rust in the same way as ordinary steel. But soon the alloying elements in it cause a protective surface layer of fine-textured rust to form, thereby suppressing corrosion rate.

< 12 >