GB 8182-87 specifies the general requirements for the seamless pipes and tubes of tantalum and tantalum alloys. The tantalum and tantalum alloys referred to in this standard include the alloys of tantalum, niobium and other elements. The alloys may have different amounts of composition and form different phases. They are characterized by large mechanical and chemical properties.
The standard includes the chemical composition, mechanical properties, size, shape, physical properties and their tolerance values.
The mechanical properties detailed in the standard include tensile strength, yield strength and elongation, while the chemical composition includes niobium, tantalum, oxygen, nitrogen, carbon and hydrogen. The standard also defines the allowable variation of the dimensions, angles and weights of the pipes mentioned in the standard.
To determine the mechanical properties, tantalum and alloys mentioned in the standard, tests such as tension tests, flattening tests, hardness tests, wedge cut tests and impact tests are performed. The chemical properties are specified in terms of the typical chemical composition and limits of constituent elements.
The environment in which these pipes and tubes are to be used is equally important, since they need to be exposed to extremely high temperatures and corrosives, and hence the mechanical properties should be able to withstand such conditions. To fulfill this requirement, a number of tests are performed on the material to understand the behavior of the material when exposed to specific environment. The tests performed include salt spray tests, natural gas test, vacuum test and oxidation tests.
The application of these pipes and tubes is mainly in chemical, electrical and nuclear industries. The products are used for containing corrosive or heat-sensitive materials, as well as for certain radiation monitoring systems. This standard also details the procedure for packing and shipping the finished goods and for certifying the material composition and mechanical properties.
