Stainless teelRound Bar is an alloy steel with smooth surface, high weldability, corrosion resistance, polishability, heat
resistance, corrosion resistance and other characteristics.
I. Exceptional Corrosion Resistance (Core Advantage of High Quality)
The corrosion resistance of high quality stainless steel bars is significantly higher than that of ordinary grades, thanks to two key factors: strict alloy composition control and stable surface passivation :
High-purity alloy elements : The content of core elements such as chromium (Cr ≥10.5%), nickel (Ni, for austenitic grades), and molybdenum (Mo, for corrosion-resistant grades) strictly complies with or exceeds standard requirements. For example:
High-quality 304 stainless steel bars ensure Cr content of 18.0-20.0% and Ni content of 8.0-10.5% (no "low-nickel" cutting corners), which can resist mild acids (vinegar, citric acid), household detergents, and humid environments without rusting for a long time.
High-quality 316L stainless steel bars (low carbon type) add 2.0-3.0% Mo, and the carbon content is controlled below 0.03% , which not only improves resistance to strong corrosive media such as seawater, sulfuric acid, and chlorine-containing solutions but also avoids intergranular corrosion caused by carbon precipitation during welding/heat treatment (critical for chemical and marine engineering).
Uniform passive film : After professional surface treatment (e.g., pickling, passivation), a dense and uniform chromium oxide (Cr₂O₃) film is formed on the surface. The film has no defects (such as pinholes or gaps) and can quickly self-repair if slightly damaged (e.g., scratches), preventing internal steel from being eroded.
II. Outstanding Mechanical Properties (Stability & Reliability)
High quality stainless steel bars undergo strict heat treatment (e.g., solution annealing, quenching and tempering) and mechanical processing, ensuring stable and excellent strength, toughness, and wear resistance—critical for load-bearing and precision applications:
High and stable strength :
Tensile strength: High-quality 304 stainless steel bars have a tensile strength of 515-795 MPa (ordinary bars may fluctuate by ±50 MPa), and 316L bars reach 485-760 MPa; for martensitic grades (e.g., 410), the tensile strength can exceed 800 MPa after quenching, suitable for high-load components such as shafts and fasteners.
Yield strength: ≥205 MPa for 304 (ordinary bars may be as low as 180 MPa), ensuring no permanent deformation under long-term static loads (e.g., mechanical supports).
Excellent toughness and ductility :
Austenitic grades (304, 316L) have an elongation rate of ≥40% (ordinary bars may be ≤35%), which can withstand bending, stamping, and even low-temperature impacts (-196°C for 304) without cracking—ideal for precision parts that require shaping (e.g., medical instrument components).
No brittle transition at low temperatures: Unlike carbon steel, high-quality stainless steel bars retain good toughness in cold environments (e.g., polar engineering, refrigeration equipment), avoiding sudden fracture risks.
Wear resistance (grade-dependent) : Martensitic stainless steel bars (e.g., 420, 440C) undergo precise quenching and tempering, with a hardness of up to HRC 58-62. They are wear-resistant and suitable for high-speed rotating parts (e.g., bearings, cutting tools) or components that are frequently rubbed (e.g., valve cores).
