The difference between carbon steel flange and stainless steel flange
The difference between carbon steel flange and stainless steel flange
corrosion resistance
Carbon steel flange:
Without passivation film protection, it is prone to rusting in humid environments and acidic or alkaline media, especially when exposed to salt spray and sulfides, which accelerates corrosion. For example, carbon steel flanges exposed to seawater may show significant rust within six months.
Stainless steel flange:
Chromium reacts with oxygen to form a dense Cr ₂ O Ⅲ passivation film, which is resistant to atmospheric, water, and weak acid alkali corrosion. 316 stainless steel has significantly better corrosion resistance to chloride ions (such as seawater and hydrochloric acid) than 304 due to its molybdenum content.
2. Strength and high temperature resistance
Carbon steel flange:
High strength at room temperature (such as Q235 yield strength ≥ 235MPa), but the strength decreases significantly at high temperatures, and the applicable temperature is usually ≤ 350 ℃. For example, the strength of 20 # steel decreases by about 30% at 400 ℃.
Stainless steel flange:
The strength at room temperature is slightly lower than that of carbon steel (such as 304 yield strength ≥ 205MPa), but it has good high-temperature stability. 310S stainless steel can withstand high temperatures of 1200 ℃ and has excellent creep resistance.
3. Processing and weldability
Carbon steel flange:
Good machinability, welding does not require special processes (such as ordinary welding rods), but after welding, attention should be paid to rust prevention treatment (such as painting with anti-corrosion paint).
Stainless steel flange:
Easy to stick to the tool during processing (high hardness, strong toughness), requiring specialized cutting tools; Welding requires temperature control (to avoid intergranular corrosion), commonly using argon arc welding or specialized stainless steel welding rods (such as A102, A132).
4. Appearance and maintenance
Carbon steel flange:
The surface is silver gray and prone to oxidation and blackening, requiring regular painting (such as galvanizing or brushing anti rust paint), which incurs high maintenance costs.
Stainless steel flange:
The surface is shiny and turns silver white after passivation. It does not require daily maintenance and remains smooth even after long-term use (only requires wiping to remove stains).
