Alloy C-4 is an austenitic nickel-molybdenum-chromium alloy with a low carbon, silicon, and iron content. This alloy has a significantly lower tendency to form precipitation in the temperature range between 650 and 1,040 °C(1,202 - 1,904 °F), improving its resistance to inter-crystalline corrosion. When machined perfectly, no knife line attack occurs in the heat-affected zones of awelding edge. Alloy C-4 is characterized by: Very good resistance in a broad field of corrosive media, in particular under strongly oxidizing conditions. Excellent resistance to pitting, crevice and stress corrosion.
Socket welded pipe cap welded to the end of the pipe or mounted on the external thread of the pipe end to cover the pipe. It is used to seal pipelines and has the same function as pipe plugging. The form of the blind plate is similar, but the blind plate is a removable plug, and the welded tube cap is not removable.