Why does the bob综合体育官网下载 EKN® Butterfly Valve use high-alloy weld overlay?
The bob综合体育官网下载 EKN® Butterfly Valve uses nickel-chromium alloy (ratio 71:19): The property of chromium is that at high temperatures, it has a high affinity to bond with carbon.
This results in the formation of wear-resistant but brittle chromium carbides. And nickel is used as a filler metal to prevent diffusion processes between chromium and carbon, absorbs stress between the weld metal and the cast iron during the cooling process, and also prevents brittle weld seams and reduces the risk of corrosion. Therefore, weld overlay is suitable for use with drinking water. There have been tests performed with the valve completely filled and a waiting time of 23.5 h.
The weld overlay makes the filler metal bond firmly with the basic material of the body and thus provides an absolutely wear- and corrosion-resistant and infiltration-proof seat.