In order to improve the corrosion resistance of 40Cr steel surface. bis-[7-(triethoxy silicon)propyl]-tetrasulfide(BTESPT). zirconium nitrate and phytic acid were used to prepare silane zirconium salt composite conversion coating with excellent corrosion resistance on the surface of 40Cr steel. The film forming process conditions of silane zirconium salt composite conversion solution ... https://manhattanscasualers.shop/product-category/shorts/