What characteristics should the boiler steel tube have

Due to long-term operation of the boiler steel tube under high temperature and high pressure conditions, the material will creep, its plasticity and toughness will decrease, the original structure will change, and corrosion will occur. The boiler steel tube shall have below characteristics:

(1) Sufficient endurance strength;
(2) Sufficient plastic deformation capacity;
(3) Minimum ageing tendency and hot brittleness;
(4) High oxidation resistance, coal ash resistance, natural gas corrosion resistance at high temperature, steam and stress corrosion resistance;

(5) Good organizational stability and good process performance. The steel types of high-pressure boiler steel tubes are carbon steel and pearlite, ferrite and austenitic stainless heat-resistant steel. In order to improve the thermal efficiency of thermal power generating units and reduce fuel consumption, all countries in the world focus on the development of large-capacity, high-parameter (high-temperature, high-pressure) thermal power units (above 1000MW). The steam pressure is increased to 31.5 ～ 34.3MPa, the superheated steam temperature is 595 ～ 650 ℃, and it is developing towards the ultra-high pressure critical pressure, which puts forward higher requirements on the high-pressure boiler steel tube. To this end, new steel grades have been developed to meet the needs of high-parameter power station boilers.