1. Cov kav hlau S275JR puas tuaj yeem welded, thiab yuav tsum tau ceev faj dab tsi?
Teb: Yog, S275JR yog welding heev siv cov txheej txheem (MIG, TIG, arc vuam). Kev ceev faj tseem ceeb:
Tsis txhob tso cua sov ntau dhau (kom tiv thaiv cov nplej coarsening thiab txo cov tawv nqaij);
Preheat only for thick sections (>25mm) lossis qhov chaw txias (tsawg dua lossis sib npaug li 5 degree) los tiv thaiv hydrogen-induced cracking;
Siv tsawg-hydrogen electrodes/fillers (E7018 rau arc vuam) yog vuam tuab;
Cia txias txias rau cov welds loj kom tswj tau qhov ductility.
2. Dab tsi yog qhov kub thiab txias rau S275JR yeeb nkab kev pab?
Teb: S275JR performs reliably in -20°C to +300°C for most structural applications. Below -20°C, its impact toughness may decline (opt for S275JO/J2 grades for lower temperatures, with impact tests at 0°C/-20°C). Above 300°C, yield strength decreases gradually; for high-temperature service (>350 degree), xav txog alloy steels (piv txwv li, P235GH).
3. S275JR piv rau lwm cov qauv hlau zoo li A36 lossis S355JR li cas?
Teb:
vs. A36 (American standard): Zoo sib xws yield zog (A36=250 MPa; S275JR=275 MPa) thiab daim ntaub ntawv, tab sis S275JR muaj stricter tej yam yuav tsum tau thiab European zoo tswj.
vs. S355JR (siab dua- qib European steel): S355JR muaj lub zog tawm los ntau dua (355 MPa) rau qhov hnyav dua, tab sis S275JR yog tus nqi ntau dua- siv tau rau cov khoom tsis yog- tseem ceeb. S275JR yog qhov nyiam thaum lub zog xav tau nruab nrab thiab tus nqi yog qhov tseem ceeb.
4. Cov kev kho saum npoo dab tsi muaj rau cov kav dej S275JR txhawm rau txhim kho corrosion?
Teb: S275JR yog unalloyed thiab nquag xeb nyob rau hauv ib puag ncig ntub / txhoj puab heev. Kev kho mob:
Kub-dip galvanizing (zinc txheej, muab ntev- tiv thaiv corrosion rau sab nraum zoov);
Painting (primer + topcoat, nqi{1}}zoo rau sab hauv tsev / nruab nrab raug);
Epoxy txheej (rau cov raj xa dej lossis cov ntawv thov dej hiav txwv, tiv thaiv cov tshuaj lom neeg / dej tsis zoo);
Dub oxide txheej (rau kev zoo nkauj lossis me me corrosion kuj nyob rau hauv ib puag ncig qhuav).
5. Qhov kev ntsuam xyuas zoo li cas feem ntau ua rau ntawm S275JR steel kav?
Teb: Yuav kom ua tau raws li EN cov qauv, cov tuam txhab ua haujlwm:
Tshuaj ntsuam xyuas muaj pes tsawg leeg (spectrometry);
Mechanical tests (tensile, yield, elongation, impact testing);
Dimensional checks (sab nraud txoj kab uas hla, phab ntsa thickness, ncaj);
Tsis yog-kev kuaj kev puas tsuaj (NDT): Kev kuaj ultrasonic (rau cov kav dej seamless) lossis kuaj hluav taws xob / sib nqus particle (rau welds, txhawm rau kuaj cov kab nrib pleb);
Kev tshuaj xyuas saum npoo (kev kuaj pom lossis eddy tam sim no los kuaj xyuas qhov tsis xws li khawb lossis xeb).
