ASTM B444 is a standard specification that covers nickel-chromium-molybdenum-columbium (Ni-Cr-Mo-Cb) alloys (UNS N06625 and UNS N06852) and nickel-chromium-molybdenum-silicon (Ni-Cr-Mo-Si) alloy (UNS N06219) in the form of seamless and welded tubes for general corrosion-resisting and heat-resisting applications.
The specification defines the chemical composition, mechanical properties, and other requirements for seamless and welded tubes made from these alloys. The tubes are available in various sizes and thicknesses, and are typically used in applications where high strength, corrosion resistance, and heat resistance are required, such as in chemical processing, aerospace, nuclear, and power generation industries.
The ASTM B444 specification provides guidelines for the manufacturing process, testing, and inspection of the tubes, including hydrostatic testing, non-destructive testing, and surface inspection. The specification also covers marking requirements and packaging for shipment of the tubes.
Overall, ASTM B444 is an important standard in the materials industry as it provides a clear set of guidelines for the manufacturing and testing of nickel alloy tubes, ensuring that they meet specific requirements for use in critical applications.