Sherardized Buckles versus Phosphated Buckles
Sherardizing is a method used to provide steel objects with a high-quality corrosion resistant, roughened zinc layer through diffusion.
The metal uncoated steel buckles are heated in a sealed rotating drum to which sand and zinc powder are added.
Next, the drum is heated while turning up to a temperature between 320°C and 500°C. The above will start a diffusion process and a uniform, heat-resistant, hard and long-wearing zinc/iron alloying layer is formed with excellent corrosion-resistant properties.
The sherardization process meets the EN standard (European Standard) 13811, class 15.
Aim of sherardizing buckles:
- High-quality and long-lasting corrosion protection.
- Rougher surface, which increases the tensile strength of the buckle considerably
without the strapping or lashing being weakened or damaged due to it.
Sherardizing
- High-quality corrosion resistance
- Surface roughness = RA value = 6.3
- Uniform zinc/sand layer, thickness approx. 20µ
- Hardness up to 450 HV (41 HRC) = impact-
resistant/long-wearing
- Complies with EN (European Standard) 13811
- Will not become detached when tensioning
strapping
- The buckle will not fracture due to hydrogen
brittleness
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Phosphating
- Nearly no to no corrosion resistance
- Surface roughness = RA value = 0.8
- Irregular zinc layer, thickness 0 - 1µ
- Impact-resistant/long-wearing = non-
existent
- Does not meet any standard
- Wears away when tensioning
strapping
- The buckle may fracture due to
hydrogen brittleness
|
Environmental issues
Sherardizing is a closed process where no environmentally hazardous acids or gasses are released.
Chemical waste flows are not created. The process water is fully recycled as cooling and rinsing water.
Sherardizing is, therefore, regarded as having nearly no environmental negative effects and offering a high-quality corrosion protection and surface roughening.
