On December 14, 2020, with the 168 hour test run of Huaneng Ruijin Power Plant Unit 4 completed, Huaneng Ruijin Power Plant Phase II Project will be completed and put into operation.
The project is the first large-scale smart power plant in China to adopt the national production control and information system (DCS/DEH+SIS), which marks that a relatively complete infrastructure network security system has been formed in China's power generation field.
Huaneng Ruijin Power Plant Phase II Project is to build two 1 million kilowatt efficient ultra supercritical secondary reheat units, using nickel iron base HT700T superalloy.
For the first time, the project adopts the nickel iron base aging strengthening superalloy HT700T developed by CZSD Superalloy Material Technology Group, which has good high-temperature structure stability, excellent comprehensive performance and high cost performance.
The successful application of nickel iron base HT700T superalloy in Huaneng Ruijin Power Plant marks that the independent research, development and manufacturing of key high-temperature components of high parameter and large capacity units in China has achieved nationwide production.
Nickel iron base HT700T superalloy
CZSD systematically studied the microstructure and properties of a new nickel iron base HT700T superalloy for the final superheater of 700 ℃ advanced ultra supercritical (A-USC) units.
The results show that:
The Ni Fe based HT700T superalloy is a precipitation strengthening alloy, and its microstructure is stable at 750 ℃;
The yield strength of HT700T superalloy is 598 MPa at 750 ℃, and it is still about 400 MPa after 3000 h of heat exposure;
The rupture strength of HT700T superalloy at 750 ℃/105h is 103 MPa;
After thermal exposure at 750 ℃ for 104h, the impact energy at room temperature is 50 J · cm-2, which is slightly lower than that before thermal exposure;
The steam oxidation resistance of HT700T superalloy reaches the full oxidation resistance level at 750 ℃ × The metal corrosion depth is about 0.2 mm under 105h simulated soot/flue gas conditions;
The comprehensive performance of HT700T alloy basically meets the service performance requirements of the final superheater of 700 ℃ A-USC unit, and its industrial trial production boiler tubes have operated normally on the test platform for more than 15000 h.