The basic requirements of steel for boiler and pressure vessel mainly include the following three aspects:

(1) with good mechanical properties. First of all, the materials used to manufacture boilers and pressure vessels should have appropriate strength (mainly referring to yield strength and tensile strength) to prevent plastic deformation or even fracture when subjected to pressure. For boilers and medium and high temperature pressure vessels, the creep resistance of the material should also be considered, and the high temperature performance index of the material, that is, the creep limit and lasting strength, should be determined.

(2) The materials used for manufacturing boilers and pressure vessels must have good plasticity to prevent damage caused by accidental overload during the use of boilers and pressure vessels.

(3) The materials used for manufacturing boilers and pressure vessels should have high toughness, so that the boilers and pressure vessels can withstand the impact loads that may be encountered during operation. In particular, for pressure vessels with low operating temperature or ambient temperature, the impact toughness value of the material should be considered, and the impact test at the operating temperature should be carried out on the material to prevent the brittleness of the container during operation.