1. Dab tsi txawv ntawm lub taub hau- cov hlua tawv tawv los ntawm cov qauv tsheb ciav hlau?
Lub taub hau- cov hlua tawv tawv tau txais kev kho cua sov tshwj xeeb ua tiav: 1) Nto hardness ntawm 340-380HB (vs 260HB rau tus qauv), 2) 50% kev pab cuam lub neej ntev dua nyob rau hauv nkhaus, 3) Txhim khu kev tiv thaiv rau kev sib tsoo thiab tawg. Cov txheej txheem cuam tshuam nrog dej quenching lub taub hau tsheb ciav hlau tom qab kub dov, tsim kom muaj martensitic microstructure mus rau 15mm qhov tob. Cov tsheb ciav hlau no raug nqi 25-30% ntau dua tab sis raug nqi zoo rau txoj kev taug kev hnyav.
2. Yuav ua li cas engineers xaiv rails hnyav -haul vs high{2}} kab ceev?
Hnyav-haul railways (40-ton axle loads) xav tau: 1) Hardness siab dua (R350HT qib), 2) Hla hla ntau dua -sections (70kg/m+), 3) Lub taub hau- kho hardened. Siab - kab ceev (300km / h +) ua ntej: 1) Precise geometry tolerances (± 0.3mm), 2) Fatigue-resistant steel, 3) Nruam welded rail (CWR) nrog kev tswj kev ntxhov siab. Ob daim ntawv thov thov ultrasonic soj ntsuam zaus txhua 50 MGT.
3. Dab tsi ua rau rail corrugation thiab yuav txo tau li cas?
Corrugation (wavelength 30-300mm) tau los ntawm: 1) Stick{13}}slip vibration ntawm lub log / tsheb ciav hlau, 2) Cov khoom siv sib txawv, 3) Resonance cuam tshuam. Countermeasures muaj xws li: 1) Optimized log profiles (1:40 conicity), 2) Friction modifiers, 3) Kev sib tsoo tsis tu ncua ua ntej corrugation tshaj 0.1mm qhov tob. Cov kev daws teeb meem tshiab suav nrog laser cladding hnav-tiv taus alloys hauv thaj chaw teeb meem.
4. Sib piv UIC60 thiab AREMA 115RE rail profiles
Qhov sib txawv tseem ceeb: 1) UIC60 muaj 60kg / m linear hnyav vs 115RE's 56.9kg / m, 2) Lub taub hau dav txawv (72mm vs 66mm), 3) Web thickness txawv (16.5mm vs 15.1mm). 115RE profile haum rau North American kev sib koom ua ke kev coj noj coj ua, thaum UIC60 yog tsim los rau kev sib txuas txuas txuas ntxiv. Ob leeg ua tau raws li qhov yuav tsum tau ua ntawm kev xeem sib txawv (UIC: -20 degree, AREMA: -40 degree).
5. Yuav ua li cas cov thermite-welded rail joints kuaj?
Tom qab-weld verification suav nrog: 1) Ultrasonic kuaj rau qhov tsis muaj - ntawm- fusion defects, 2) Hardness mapping (yuav tsum phim niam txiv rail nyob rau hauv 20HB), 3) Tensile testing mus rau 900MPa yam tsawg kawg nkaus, 4) Macro-etching los tshuaj xyuas microstructure. Cov kev coj ua niaj hnub no ntxiv cov theem-array UT txhawm rau txheeb xyuas cov sub{12}} millimeter flaws. Welds yuav tsum ua siab ntev 2 lab lub voj voog hauv kev sim qaug zog.