电力与能源
電力與能源
전력여능원
Power and Energy
2014年
4期
481-482,487
,共3页
再热器出口集箱%管座角焊缝%焊接接头型式%脆性断裂%焊接裂纹分析
再熱器齣口集箱%管座角銲縫%銲接接頭型式%脆性斷裂%銲接裂紋分析
재열기출구집상%관좌각한봉%한접접두형식%취성단렬%한접렬문분석
Final reheater header%Joint fillet welds%Welded joint type%Brittle fracture%Fillet weld analysis
末级再热器出口集箱管座发生裂纹，是长期困扰燃煤电厂的重大设备隐患。通过分析末级再热器出口集箱管座上部角焊缝热影响区产生裂纹的原因及焊接装配形式的分析，认为不合理的焊接接头型式、较大的拘束应力和长期高温运行后导致金属热强性降低，是集箱管座产生裂纹的主要原因。为此，按照 DL/T 869-2012标准要求，将承插式焊接接头改为全焊透焊接接头，用加强型管座提高焊接接头强度，控制焊接工艺参数等措施，提高了焊接接头的强度和高温力学性能，消除了超标焊接隐患。12号锅炉从2011年12月大修后运行至今，末级再热器出口集箱焊口经过多次磁粉探伤，均未发现裂纹等超标缺陷，证实了改进集箱管座焊接接头型式是正确的。
末級再熱器齣口集箱管座髮生裂紋，是長期睏擾燃煤電廠的重大設備隱患。通過分析末級再熱器齣口集箱管座上部角銲縫熱影響區產生裂紋的原因及銲接裝配形式的分析，認為不閤理的銲接接頭型式、較大的拘束應力和長期高溫運行後導緻金屬熱彊性降低，是集箱管座產生裂紋的主要原因。為此，按照 DL/T 869-2012標準要求，將承插式銲接接頭改為全銲透銲接接頭，用加彊型管座提高銲接接頭彊度，控製銲接工藝參數等措施，提高瞭銲接接頭的彊度和高溫力學性能，消除瞭超標銲接隱患。12號鍋爐從2011年12月大脩後運行至今，末級再熱器齣口集箱銲口經過多次磁粉探傷，均未髮現裂紋等超標缺陷，證實瞭改進集箱管座銲接接頭型式是正確的。
말급재열기출구집상관좌발생렬문，시장기곤우연매전엄적중대설비은환。통과분석말급재열기출구집상관좌상부각한봉열영향구산생렬문적원인급한접장배형식적분석，인위불합리적한접접두형식、교대적구속응력화장기고온운행후도치금속열강성강저，시집상관좌산생렬문적주요원인。위차，안조 DL/T 869-2012표준요구，장승삽식한접접두개위전한투한접접두，용가강형관좌제고한접접두강도，공제한접공예삼수등조시，제고료한접접두적강도화고온역학성능，소제료초표한접은환。12호과로종2011년12월대수후운행지금，말급재열기출구집상한구경과다차자분탐상，균미발현렬문등초표결함，증실료개진집상관좌한접접두형식시정학적。
Fillet welds on outlet header joint of final reheater,is a major equipment hidden danger which has troubled coal-fired power plants for a long time.Through analysis of fillet welds on outlet header joint of final reheater and welding assembly type,found main reasons are unreasonable welded joint type,excessive re-straint stress and decreasing of metal heat resisting strength while boiler operated under high temperature for a long time.Therefore,in accordance with the DL/T 869-2012 standard requirements,change socket-welded joints to full penetration welding joint,use reinforced header to increase the strength of welded joint,and con-trol of welding process parameters can improve the strength of welded joint and high temperature mechanical properties,that eliminates the hidden trouble of excessive welding.After No.12 boiler overhauled in Decem-ber 2011 and operated to now,we have not found excessive defects such as fillet welds on header joint of final reheater after many magnetic particle testing,it’s confirmed that improved the welded joint type is correct.
