Dawtchiah, Hangao Tehc (Seko machinery) chuan welding process chhunga harsatna awm thei te hrethiam turin a hruai chhunzawm zel ang che a, chutiang harsatna awm thei tur ven leh chinfelna kawngah a pui ang che.
03 Welding Hot Cracks (WELD-a crystallization crack, heat-a nghawng zone-a liquefaction cracks)
Thermal cracking sensitivity hi a bik takin a thil siam chemical composition, organization leh a performance ah a innghat a ni. Ni hi low melting point compound emaw eutectic emaw siam awlsam a ni a, bawlhhlawh s leh P. Boron leh silicon te inthen darh hian thermal cracking a tichak ang.
Weld seam hi coarse columnar crystal structure siam a awlsam a, directionality chak tak a nei a, hei hi thil tha lo leh element hrang hrang hlauhawm tak tak thliar hranna atan a tha hle. Hei hian continuous intergranular liquid film siam a tichak a, thermal cracking sensitivity a ti tha bawk. Welding chu uniform taka tihlum a nih loh chuan tensile stress lian zawk siam a, welding hot crack siam chhuah a awlsam.
Invenna tur ruahmanna: 1.1.
ani. Thil bawlhhlawh hlauhawm tak tak awm zat chu khauh takin control rawh s leh p.
b. Weld metal buatsaih dan tur siamrem rawh. Dual-phase structure weld hian crack resistance tha tak a nei a. Weld-a delta phase hian grains te chu a tithianghlim thei a, single-phase austenite-a directionality a ti bo thei a, grain boundary-a bawlhhlawh hlauhawm tak takte thliar hranna a tihtlem thei a, delta phase chuan S leh P te chu a ti bo thei a, interfacial energy a tihtlem thei a, intergranular liquid film siamna a buatsaih thei bawk.
c. Weld metal alloy composition chu siam tha rawh. Single-phase austenitic steel-a Mn, C, leh N awm zat chu a remchan dan angin a tipung a, trace element tlemte cerium, pickaxe, leh tantalum (weld structure tithianghlim thei leh grain boundary tithianghlim thei) te pawh a dah tel bawk a, hei hian thermal cracking sensitivity a ti tlem thei a ni.
d. Process measures tih te a ni. Columnar crystal thick tak tak lo awm tur ven nan molten pool overheating tih tlem rawh. Heat input te tak te leh cross-section weld beads te hmang la. Chu Welding lai hian arc stabilizing device dah belh theih a ni a, chu chuan molten pool area a tihtlem bakah welding gun hnathawh dan a ti tha a, welding quality pawh a ti tha thei bawk.
Entirnan, 25-20 austenitic steel hian liquefaction crack a thlen awlsam hle. Base material-a impurity awm zat leh grain size khauh taka tihtlem te, high-energy density welding method hman te, heat input tlem te leh joint-te cooling rate tihsan te a theih a ni.
04 Welded joint te chu a hnial .
Heat-strength steel hian welded joint plasticity a enfiah tur a ni a, chu chuan high-temperature embrittlement a veng thei ang; Low-temperature steel te hi welded joint te low-temperature brittle fracture ven nan low-temperature toughness tha tak neih a ngai a ni.
05 Welding distortion lian tak .
Thermal conductivity hniam leh expansion coefficient lian tak avang hian welding deformation a lian hle a, clamp hmangin deformation a awm loh nan. Austenitic stainless steel hmanga welding dan leh welding material thlan dan:
Austenitic stainless steel chu argon tungsten arc welding (TIG), molten argon arc welding (MIG), plasma argon arc welding (paw) leh tui hnuaia awm Arc Welding (SAW) te hmangin weld theih a ni.
Austenitic stainless steel hian welding current hniam tak a nei a, a chhan chu a melting point a hniam a, thermal conductivity a hniam a, electrical resistivity a sang bawk. Lorrow welds leh beads te hi high-temperature residence time tihtlem nan te, carbide precipitation ven nan te, weld shrinkage stress tihziaawmna tur te, thermal crack sensitivity tihtlem nan te hman tur a ni.
Welding material composition, a bik takin CR leh Ni alloying elements te hi base material aiin a sang zawk a ni. Weld-a crack resistance tha tak (cold cracking, hot cracking, stress corrosion cracking) performance tha tak neih theih nan welding materials tlemte (4-12%) awmna welding material hmang ang che.
Weld-a ferrite phase phal loh emaw, tih theih loh emaw a nih chuan welding material chu welding material Mo, MN leh alloy element dangte awmna a ni tur a ni.
Welding material-a C, S, P, SI, leh NB te chu a hniam thei ang bera hniam tur a ni. NB hian pure austenitic weld-ah solidification crack a thlen ang a, mahse weld-a ferrite tlemte chu a tha zawngin a pumpelh theih.
Welding structures stabilized emaw welding hnua stress-relieved emaw ngai tan chuan NB-containing welding materials hman a ni tlangpui. Submerged arc welding hi middle plate weld nan hman a ni a, CR leh Ni kang lo chu welding wire-a flux leh alloy elements inthlak danglamna hmangin tihpun theih a ni a
Penetration depth lian tak avang hian weld lai takah hot cracks a awm loh nan leh heat-affected zone-a corrosion resistance a tlahniam loh nan fimkhur a ngai a ni. Thinner welding wire leh welding heat input te zawk thlan tur a ni. Welding wire hi SI, S, leh p-ah a hniam a ngai a ni.
Heat-resistant stainless steel weld-a ferrite awm zat chu 5% aia tam lo tur a ni. Austenitic stainless steel CR leh Ni content 20% aia tam tan chuan MN sang (6-8%) welding wire hman tur a ni a, alkaline emaw neutral flux chu weld-a SI dah loh nan leh a crack resistance tihchangtlun nan flux atan hman tur a ni.
Austenitic stainless steel atana special flux hian SI a tipung tlem hle a, chu chuan alloy chu weld-ah a transfer thei a, weld performance leh chemical composition mamawh phuhruk nan alloy elements kang chu a rul thei bawk.
