Cov tshuaj muaj pes tsawg leeg ntawm Q355B yog nruj me ntsis txwv nyob rau hauv GB/T 1591-2018 los xyuas kom meej nws weldability, lub zog, thiab toughness. Nws yog ib qho qis- alloy steel qhov twg cov ntsiab lus xws li Manganese (Mn) thiab Silicon (Si) yog thawj cov neeg ua kom muaj zog, nrog rau micro-ntxiv ntxiv ntawm Niobium (Nb), Vanadium (V), thiab titanium (Ti) rau cov nplej ua kom zoo thiab nag lossis daus. Cov kev txwv tsis pub muaj sib txawv me ntsis nrog cov khoom tuab los lav cov khoom sib xws. Cov ntsiab lus tseem ceeb thiab lawv lub luag haujlwm / txwv yog: Carbon (C): Feem ntau ≤ 0.20-0.24% max (nyob ntawm thickness). Carbon nce lub zog tab sis ua mob weldability thiab toughness. Silicon (Si): ≤ 0.50-0.55%. Nws yog ib qho deoxidizer thiab cov kua nplaum uas muaj zog. Manganese (Mn): ≤ 1.60%. Ib qho tseem ceeb ntxiv dag zog thiab toughness enhancer. Phosphorus (P) thiab Sulfur (S): Ob qho tib si raug tswj kom qis (P≤0.030%, S≤0.030% rau Qib B) vim tias lawv yog cov impurities uas ua rau brittleness. Qib "B" qhia txog qhov siab tshaj plaws Carbon Equivalent (CEV) kom ntseeg tau zoo weldability; CEV yog xam los ntawm IIW formula: CEV=C + Mn/{21}} (Cr+Mo+V)/5 + (Ni+Cu)/15. Rau Q355B, CEV feem ntau yuav tsum yog ≤ tus nqi teev (piv txwv li, 0.43-0.45 nyob ntawm thickness) rau preheating xam hauv vuam. Piv rau Q355A, Qib B muaj kev tswj nruj dua ntawm Phosphorus thiab Sulfur thiab yuav tsum tau kuaj qhov cuam tshuam.
* Cov lus: Cov tshuaj lom neeg muaj pes tsawg leeg rau Q355B (GB / T 1591-2018, thickness ≤ 40mm piv txwv) *
| Lub ntsiab | C (max) | Si (max) | Mn (max) | P (max) | S (max) | Nb (max) | V (max) | Ti (max) | Cu (max) | CEV (max, approx.) |
|---|---|---|---|---|---|---|---|---|---|---|
| Q355B | 0.24% | 0.55% | 1.60% | 0.030% | 0.030% | 0.05% | 0.15% | 0.20% | 0.40% | 0.43-0.45 |