I. Visual Inspection: Look for obvious rust features
The most obvious signs of rust are changes in color and surface condition. Pay close attention to the following:
* Reddish-brown or orange-yellow spots on the work surface: This is a typical characteristic of iron oxides (Fe₂O₃), commonly found at the edges of holes, T-slots, or low-lying areas of the workbench.
* Surface darkening, discoloration, or loss of metallic luster: A workbench that has been milled or blackened should be a uniform grayish-black or dark gray. Localized darkening or grayish-white discoloration may indicate early oxidation.
* Powdery rust inside holes: Illuminate the positioning holes with a strong light. If reddish-brown dust or clumps are found inside, it indicates deep oxidation.
* Peeling off the anti-spatter coating accompanied by discoloration: Exposed metal areas after coating damage are susceptible to corrosion, often showing edge peeling and central rust.
✅ Special Reminder: In high humidity environments, cast iron platforms may develop a "water film" or "sweat droplets" on their surface. If not removed promptly, visible rust can form within 48 hours.
II. Tactile Judgment: Identifying Potential Problems by Touch
Even if no obvious rust is visible to the naked eye, abnormalities can be detected by touch:
Rough or Grainy Feel: A normal platform should be smooth and flat. If there is resistance when sliding your finger, it may be due to micro-rust or an oxide layer.
Yellowish-Brown Stains Left on the Cloth After Wiping: Gently wipe the platform with a clean cotton cloth. If the cloth is stained, it indicates an active oxidation reaction.
Resistance or Jamming When Inserting Positioning Pins: Micro-rust on the hole walls can cause poor fit, affecting repeatability and positioning accuracy.
It is recommended to incorporate a simple "look, touch, wipe" process into daily inspections to improve early detection capabilities.
III. Environmental Factors and Usage to Auxiliary Judgment
The following situations, even without visible rust, should raise a high suspicion of corrosion risk:
The relative humidity of the working environment is consistently above 60%, and ventilation is poor;
Equipment is shut down at night or on weekends, leading to condensation due to diurnal temperature variations;
Welding slag or oil stains are not promptly cleaned after use, leaving residues that absorb moisture and create a localized corrosive environment;
The equipment has not been used for more than 7 consecutive days without protective covering.
If you are located in Wuxi during the rainy season (usually June-July), when air humidity often exceeds 80%, even if the surface appears normal, you should still check monthly for latent corrosion.
