|
Comparison Dimension |
304 Stainless Steel |
316L Stainless Steel |
|
Chromium (Cr) |
18%–20% |
16%–18% |
|
Nickel (Ni) |
8%–10.5% |
10%–14% |
|
Molybdenum (Mo) |
None |
2%–3% (the key differentiating element) |
|
Maximum Carbon (C) Content |
0.08% |
0.03% (L stands for low carbon) |
|
Market Price |
Base reference price |
30%–50% higher |
Molybdenum is the critical element for resisting chloride ion corrosion. In environments involving seawater, brine, disinfectant and chlorine-containing chemical media, 304 stainless steel is highly prone to rust spots, while 316L delivers stable and long-lasting service performance. Its low-carbon formulation prevents intergranular corrosion after welding, making it the preferred material for large welded equipment.
II. Targeted Material Selection Standards by Industry
Prefer 304 Stainless Steel (Cost-Effective Applications)
1. Indoor construction: stair handrails, curtain walls, decorative mouldings, stainless steel doors and windows
2. Civil kitchen & bathroom products: vacuum flasks, water sinks, kitchen utensils, indoor water supply pipelines
3. General machinery: equipment casings for dry workshops, storage racks, standard fasteners
4. Inland municipal facilities, conventional cold storage tanks
Mandatory Selection of 316L Stainless Steel (Severe High-Corrosion Environments)
1. Coastal outdoor facilities: seaside railings, photovoltaic supports, coastal guardrails (rich in salt spray and chloride ions)
2. Marine engineering: ship piping, seawater desalination equipment, swimming pool water circulation systems
3. High-end pharmaceutical & food production lines: pharmaceutical reactors, sterile transfer pipelines, food fermentation equipment
4. Chemical industry: acid & alkali storage tanks, heat exchange pipes for desulfurization and denitrification, high-pressure welded vessels
5. Medical devices, high-temperature hydrogenation and energy storage equipment
III. Procurement Cost Optimization Recommendations
Choose 304 for long-term indoor inland projects to control upfront costs. For long-term coastal, chemical and outdoor engineering projects, directly adopt 316L to cut later expenses on corrosion-related maintenance and replacement, resulting in a lower overall life-cycle cost. 304 may be adopted as needed for short-term temporary projects.
