SA-179 seamless steel tubes, tseem hu ua cua kub exchanger raj raws li ASME SA-179M tus qauv, yog seamless steel raj khoom raws li ASME (American Society of Mechanical Engineers) cov qauv.
SA-178A yog ib hom seamless carbon steel raj raws li tus qauv ASME, tshwj xeeb tshaj yog rau kev tiv thaiv-welded carbon steel thiab carbon-manganese steel boiler thiab superheater raj.
Chemical Composition Table Comparison Table (Unit: Cov Feem Xyuam, %)
| Element | ASTM A178 (SA178) | ASTM A179 (SA179) | Sau ntawv |
|---|---|---|---|
| Cov pa roj carbon (C) | Tsawg dua lossis sib npaug rau 0.18 (Qib A) Tsawg dua lossis sib npaug rau 0.23 (Qib C) Tsawg dua lossis sib npaug rau 0.30 (Qib D) |
Tsawg dua lossis sib npaug li 0.06 | SA178, raws li kev tiv thaiv- welded raj, muaj ntau cov pa roj carbon ntau; SA179, raws li qhov txias txias - kos seamless raj, nruj me ntsis txwv cov pa roj carbon monoxide los txhim kho weldability thiab toughness |
| Manganese (Mn) | Tsawg dua lossis sib npaug rau 0.90 (Qib A) Tsawg dua lossis sib npaug li 1.00 (Qib C) Tsawg dua lossis sib npaug rau 1.20 (Qib D) |
0.27–0.63 | SA179 tswj nruj dua manganese tswj kom ntseeg tau tias microstructure tsis sib xws tom qab kos duab txias |
| Silicon (Si) | Tsawg dua los yog sib npaug li 0.30 | Tsawg dua lossis sib npaug li 0.25 | Ob leeg txwv silicon kom txo qis qhov cuam tshuam tsis zoo ntawm weldability |
| Phosphorus (P) | Tsawg dua lossis sib npaug li 0.035 | Tsawg dua lossis sib npaug li 0.035 | Kev tswj nruj nruj kom tsis txhob txias brittleness |
| Sulfur (S) | Tsawg dua lossis sib npaug li 0.035 | Tsawg dua lossis sib npaug li 0.035 | Ob leeg xav tau cov ntsiab lus tsis tshua muaj sulfur los tswj cov ductility |
Mechanical Properties Comparison Table (Tus nqi tsawg kawg nkaus rau ASTM Standard)
| Khoom | ASTM A178 (SA178) | ASTM A179 (SA179) | Txoj Kev Xeem |
|---|---|---|---|
| Tensile zog | Qib A: Ntau dua lossis sib npaug rau 310 MPa Qib C: Ntau dua lossis sib npaug li 380 MPa Qib D: Ntau dua lossis sib npaug li 450 MPa |
Ntau dua lossis sib npaug li 325 MPa | ASTM E8/E8M |
| Yield zog | Qib A: Ntau dua lossis sib npaug ntawm 195 MPa Qib C: Ntau dua lossis sib npaug li 240 MPa Qib D: Ntau dua lossis sib npaug li 310 MPa |
Ntau dua lossis sib npaug li 180 MPa | ASTM E8/E8M |
| Elongation hauv 50mm | Qib A: Ntau dua lossis sib npaug li 25% Qib C: Ntau dua lossis sib npaug li 20% Qib D: Ntau dua lossis sib npaug li 18% |
Ntau dua lossis sib npaug li 35% | ASTM E8/E8M |
| Hardness (Rockwell B) | Tsis tau teev tseg | Tsawg dua lossis sib npaug rau 72 HRB | ASTM E18 |
Mechanical Performance Comparison Table
| Khoom | ASTM A178 (SA178) | ASTM A179 (SA179) | Sau ntawv |
|---|---|---|---|
| Elastic Modulus | ~ 200 GPa (ib txwm rau carbon steel) | ~ 200 GPa (ib txwm rau carbon steel) | Tsis muaj qhov sib txawv tseem ceeb; ob leeg yog tsawg- carbon steels |
| Impact Toughness (Charpy V-Notch) | Tsis tau teev nyob rau hauv tus qauv | Tsis tau teev nyob rau hauv tus qauv | Tsis yog tus txheej txheem tswj hwm cuam tshuam txog kev xav tau ntawm lub zog; yuav tsum tau kuaj ntxiv rau cov kev pabcuam hnyav |
| Kev qaug zog | Tsis tau teev nyob rau hauv tus qauv | Tsis tau teev nyob rau hauv tus qauv | Tsis yog tus qauv muab kev txwv qaug zog. Hauv kev tsim qauv engineering, 40% ntawm lub zog tensile feem ntau yog siv los ua kev kwv yees (~ 130 MPa) |
| Kev kho cua sov yuav tsum tau | Tshaj tawm -weld stress relief annealing | Bright annealing (Ntau dua lossis sib npaug rau 650 degree) | SA179 yuav tsum tau ci ntsa iab los txo qhov txias - ua hauj lwm kev ntxhov siab thiab txhim kho corrosion kuj thiab qhov ntev stability |