热力发电
熱力髮電
열력발전
THERMAL POWER GENERATION
2014年
9期
129-132
,共4页
史志刚%马红%崔雄华%王飞%王碧磊
史誌剛%馬紅%崔雄華%王飛%王碧磊
사지강%마홍%최웅화%왕비%왕벽뢰
T2 3%T9 1%高温过热器%短时超温%爆管%微观组织%组织性能
T2 3%T9 1%高溫過熱器%短時超溫%爆管%微觀組織%組織性能
T2 3%T9 1%고온과열기%단시초온%폭관%미관조직%조직성능
T23%T91%high temperature%superheater%shot-time over heating%tube buest%microstructure%mechanical properties
某亚临界700 MW机组锅炉T23和T91高温过热器服役近105 h时，发生短时超温爆管。为此，对其组织性能进行了试验。发现：T23微观组织明显异常，为铁素体＋无位向碳化物，抗拉强度和硬度略有升高，而规定塑性延伸强度(Rp )却显著降低；T 91微观组织略有变化，为细碎马氏体＋微量碳化物，抗拉强度和硬度显著升高。研究表明，铁素体耐热钢制高温过热器短时超温爆管后，决定其相变后组织形态的主要因素是其随炉冷却速率，并非爆管后所喷射出的工质冷却速率。
某亞臨界700 MW機組鍋爐T23和T91高溫過熱器服役近105 h時，髮生短時超溫爆管。為此，對其組織性能進行瞭試驗。髮現：T23微觀組織明顯異常，為鐵素體＋無位嚮碳化物，抗拉彊度和硬度略有升高，而規定塑性延伸彊度(Rp )卻顯著降低；T 91微觀組織略有變化，為細碎馬氏體＋微量碳化物，抗拉彊度和硬度顯著升高。研究錶明，鐵素體耐熱鋼製高溫過熱器短時超溫爆管後，決定其相變後組織形態的主要因素是其隨爐冷卻速率，併非爆管後所噴射齣的工質冷卻速率。
모아림계700 MW궤조과로T23화T91고온과열기복역근105 h시，발생단시초온폭관。위차，대기조직성능진행료시험。발현：T23미관조직명현이상，위철소체＋무위향탄화물，항랍강도화경도략유승고，이규정소성연신강도(Rp )각현저강저；T 91미관조직략유변화，위세쇄마씨체＋미량탄화물，항랍강도화경도현저승고。연구표명，철소체내열강제고온과열기단시초온폭관후，결정기상변후조직형태적주요인소시기수로냉각속솔，병비폭관후소분사출적공질냉각속솔。
Several T23 and T91 steel superheater tubes in a subcritical pressure 700 MW unit boiler had failed for short-term overheating after serving for 105 h.The mechanical properties and microstructure of the failed tubes were studied.The results show that there was an obvious change of microstructure for the failed T23 steel,whose microstructure was made of ferrite and no-orientation carbide.Its tensile strength and hardness increased weakly,while its proof strength of non-proportional elongation(Rp )decreased dra-matically.The results for T9 1 went the opposite way,with a slight change of microstructure and a signifi-cant rise of tensile strength and hardness.It indicates that the factor determining the microstructure of failed superheater tubes made by ferrite high temperature-resistance steel is the cooling rate of furtance,but not the cooling rate of ej ected fluid.
