The properties and serviceability of candidate water wall materials for 600 MW ultra supercritical (USC)unit boilers with main steam temperature of 700 ℃ were investigated,such as T12,12Cr1MoVG, T23,T24,T91,T92,T122(HCM12A),VM12 SHC and 617 mod.According to analysis on these materials'performances,including the rupture strength,thermal fatigue,creep fatigue,steam-corrosion resistance, gas-corrosion resistance,thermal mechanical properties and weldabilities,it suggests the high-strength mar-tensite steel T92 and nickel alloy 617 mod should be selected as the water wall material for 700 ℃ USC boilers.During installation,post weld heat treatment should be carried out for the T92 welded joints using electric heating panel.%针对超超临界600 MW 机组主蒸汽温度为700℃的锅炉(700℃锅炉)水冷壁选材问题,分析比较了 T12,12Cr1MoVG,T23,T24,T91,T92,T122(HCM12A),VM12 SHC 和617mod 等备选管材的适用性,包括母材和焊接接头的持久强度、热疲劳和蠕变疲劳,母材和焊接接头的抗蒸汽腐蚀和抗烟气腐蚀性能,热成型性能及可焊性。同时,提出超超临界700℃锅炉水冷壁应选用 T92高强度马氏体钢管和617mod 镍基合金管,应采用电加热板对 T92水冷壁管对接焊接接头进行焊后热处理。
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