Coal-based thermal power generation dominates China's power production. At present, the steam temperature of thermal power boilers is about 600 °C (ultra-supercritical), and the materials used for superheaters and reheaters are mainly Super304 and HR3C. When the vapor temperature rises to 700 °C (advanced super-supercritical), austenitic heat-resistant steel can no longer meet the requirements of use, and needs to be replaced by nickel-based superalloy. Developed countries have experienced the development of such new nickel-based superalloy materials for more than ten years, accumulated a large number of experimental and test data, and launched corresponding research plans (such as the US AD760 plan, the European AD700 plan, etc.). Among them, the 617B nickel-based superalloy, which is mainly promoted in Europe, is used as the main candidate material for the new generation of advanced ultra-supercritical superheaters, reheaters and main steam pipes due to its excellent comprehensive performance.
There are many research work on 617 B alloy in foreign countries, but there is little research on this alloy in China, and domestic and foreign research work is focused on the mechanical properties, high temperature corrosion performance, microstructure stability, creep properties, etc. of the finished product. There are few studies on thermal deformation and cold deformation. This paper mainly studies the thermal deformation and cold deformation behavior of 617B alloy, and provides a certain data and theoretical basis for better understanding of the nature of materials.
(1) Under the same deformation temperature condition, the peak strain of dynamic recrystallization of 617 B alloy increases with the increase of strain rate;
(2) In the 617 B alloy, the dynamic recrystallized grain size decreases first and then increases with the increase of strain rate in the range of strain rate 0.1-20 s-1;
(3) After cold deformation, when the annealing temperature is increased from 1080 °C to 1160 °C, the tensile strength and yield strength of 617B alloy pipe decrease with increasing temperature, plasticity increases, temperature continues to increase, and alloy strength and plasticity change Big. A suitable cold deformation annealing system for 617B is 1200 ° C / 30-60 min.