Proper storage and handling of stainless steel are crucial to maintaining its bright, durable finish. Care must begin at delivery and continue through fabrication, transport to the end customer and beyond.
Potential issues:
PHYSICAL DAMAGE
- Scratches or burrs: Can occur due to unprotected metallic rack supports, rough handling, inadequate packing, or contact with forklift tines. Use protective materials like wood, plastic, or carpet to minimise damage.
- Distortion or dents: Thin sheets and small-diameter tubes need adequate external support (e.g. boxes) to prevent kinking, flattening, or deformation.
- Improper storage: Poor support in pigeonhole or rack storage can lead to physical damage.
CONTAMINATION AND CORROSION
Stainless steel is vulnerable to contamination from carbon steel and chlorides, which can lead to corrosion.
- Carbon steel contamination: Grinding or polishing carbon steel will produce fine particles that spread unless there is proper local extraction. Avoid processing carbon steel and stainless steel in the same workspace.
- Shared tools and equipment: Presses and guillotines used for both materials must be cleaned thoroughly between uses or else lines of steel (and subsequent rust) can occur. Beds should be covered and wiped down immediately before handling stainless steel. Tools used for carbon steel should not be used on stainless steel.
- Tie-down straps: Avoid carbon steel tie-downs, as fretting and deposits can cause staining and pitting. Galvanised straps are also problematic due to zinc deposits, which can lead to corrosion and, in welding, liquid metal embrittlement.
- Surface contaminants: Dust, dirt, or marks from carbon-based materials (e.g. pencils, sooty flames, boots) can cause sensitisation during welding, reducing corrosion resistance. If residual dust poses a risk in tubes or pipes, end caps may be necessary.
- Chloride exposure: Common sources include seawater, sweat, hydrochloric acid fumes from brick cleaning, and food and drink residues. When the relative humidity exceeds 55%, chlorides can absorb moisture, breaking down the stainless steel’s passive film and causing rust spotting. Best practice is to shield stainless steel from chlorides, but if contamination occurs, prompt washing with low-chloride water followed by thorough drying can mitigate the risk.
- Hydrotesting considerations: Use low-chloride water free from suspended solids. Ensure the design allows for complete drainage and drying after testing to avoid long-term corrosion risks.
STORAGE BEST PRACTICES
Store stainless steel separately from carbon steel or thoroughly wrap it if shared storage is unavoidable. Clean surfaces thoroughly after unwrapping.
Indoor storage is ideal, but for outdoor storage, ensure periodic cleaning based on environmental exposure. Long-term outdoor storage of materials and fabricated goods (including after delivery to site) requires careful consideration of environmental factors, as exposure to moisture, chlorides, and pollutants can lead to corrosion, staining, and other surface damage.
Use tie-on tags or non-aggressive markers for labelling offcuts. Avoid sticky labels, as they can degrade and promote crevice corrosion in aggressive environments.
Minimise extended exposure to sunlight for plastic-wrapped items to prevent polymer and adhesive degradation.
By following these guidelines, you can preserve the quality and durability of stainless steel throughout its lifecycle.
This article was featured in Australian Stainless Magazine Issue 81.