Cov tshuaj muaj pes tsawg leeg ntawm round steel txhais nws cov khoom tseem ceeb:
Carbon steel round bars (piv txwv li, ASTM A36): Muaj 0.25-0.29% carbon, 0.80-1.20% manganese, thiab cov lej ntawm phosphorus (<0.04%) and sulfur (<0.05%). This low-alloy composition prioritizes weldability and affordability, making them ideal for structural applications like construction rebar.
Stainless hlau puag ncig tuav (xws li, 304): suav nrog 18–20% chromium thiab 8–10.5% npib tsib xee, tsim cov txheej txheem oxide passive uas tiv thaiv corrosion. 316 qib ntxiv 2-3% molybdenum rau kev txhim kho kev tiv thaiv chloride ib puag ncig (xws li, siv dej hiav txwv).
Alloy steel round bars (piv txwv li, 4140): Ua ke 0.38–0.43% carbon nrog 0.80–1.10% chromium thiab 0.15–0.25% molybdenum los txhim kho hardenability thiab tensile lub zog, siv nyob rau hauv siab - kev nyuaj siab Cheebtsam xws li shafts.
Cov kev hloov hauv cheeb tsam muaj nyob: Tuam Tshoj Q235 carbon round bars muaj cov pa roj carbon tsawg dua (<0.22%) than ASTM A36, while Europe's EN 10088-3 1.4301 (304 equivalent) specifies stricter limits on sulfur (<0.015%) for better corrosion resistance.