Microstructural evolution of delta ferrite in SAVE12 steel under heat treatment and short-term creep

Microstructure evolution and mechanical properties of multiple-layer laser cladding coating of 308L stainless steel

“…Kim et al [13] have investigated that when the weld metal of 316L stainless steel heat treatment is at 650 °C~950 °C, the δ ferrite content increases significantly with the increasing time and the temperature of heat treatment. Li et al [14] have analyzed that when SAVE12 steel anneals at 1050 °C~1100 °C, δ ferrite will be re-dissolved in the single-phase austenite. Lima et al [15] have studied the microstructure and mechanical behavior of laser additive manufactured AISI 316 stainless steel stringers.…”

Precipitates change of ferritic‐martensitic 11 % chromium steel under short‐term creep

“…The coarsening of M 6 C phase in ferrite steels is much faster than that of M 23 C 6 phase [32]. Owing to the poor dimensional stability of M 6 C carbides, the coarsening of the carbides could promote the formation of creep cavities [18,33]. In addition, solid-solution strengthening from tungsten atoms is an important strengthening mechanism for ferritic-martensitic 9 %-12 % chromium heat resistant steels [34].…”

“…And small amounts of M 6 C precipitates were detected in ferritic-martensitic 12 % chromium steels after creep exposures at 475 8C and 550 8C for 39287 h and 24024 h, respectively [17]. The dimensional stability of some precipitate phases, like M 6 X phase and Laves phase, is generally bad and they can coarsen quickly during creep exposures [18]. In addition, the precipitation of M 6 X phase can lead to a consumption of fine MX and M 2 X precipitates previously existing in ferritic-martensitic high chromium steels and a degradation in the long-term creep strength of the steels [19][20][21].…”

Tensile and creep deformation of a newly developed Ni-Fe-based superalloy for 700 °C advanced ultra-supercritical boiler applications

“…In coal-fired power plants, increasing steam temperature and pressure is an effective method for improving thermal efficiency and for reducing coal consumption as well as CO 2 and NO x emissions. The current 600°C ultra-supercritical power plants typically have a steam pressure of 25-28 MPa, and the net thermal efficiency is approximately 43-45%.…”

“…These components require a rupture life of 10 5 h while maintaining a rupture strength of greater than 100 MPa operating at 750 °C (the metal temperature is set to be 50 °C higher than steam temperature, according to the design standard of power plants in China). The temperature capability of the most advanced ferritic and austenitic heat resistant steels is around 650°C and 700°C, respectively [2,3]. Thus, they cannot meet the requirements of super-heater and reheater in 700°C A-USC boilers.…”