Black iron and white iron literally mean black iron and iron. Jinan black and white iron processing is a small workshop, mainly processing ordinary iron and galvanized iron plate and other things. They call ordinary iron "black iron" and galvanized iron (commonly known as snowflake iron), "white iron".
Black iron, also known as stainless steel, is a kind of black and white iron in Jinan. The primary color of stainless steel is black. We can see that silver stainless steel is polished by processing. For stainless steel, we call it black iron. The corrosion resistance of stainless steel decreases with the increase of carbon content. Therefore, the carbon content of most stainless steels is low, up to 1.2%, while Wc (carbon content) of some steels is lower than 0.03% (for example, 00Cr12). The main alloying element in stainless steel is chromium (chromium). As long as the chromium content reaches a certain value, the steel has the function of corrosion resistance. Therefore, the common chromium content of stainless steel is at least 10.5%. Processing of Black and White Cast Iron in Jinan
Galvanized iron sheet is commonly known as galvanized iron sheet. Clean iron sheets are dipped in concentrated liquid zinc. In contrast, zinc is indeed active, but in the humid air rich in CO2, a layer of alkaline zinc carbonate can be formed: 4Zn+2O2+3H2O+CO2_ZnCO3. The alkaline zinc carbonate film 3Zn (OH) 2 is compact and can be used as a maintenance film to avoid the internal oxidation of zinc.
Assuming that once the galvanized layer is destroyed in the future, attack electrochemical corrosion, because zinc is more vivid than iron, it will passively attack oxidation reaction and suffer losses of galvanized primary batteries. Iron is maintained and, contrary to tinplate, tinplate attacks electrochemical corrosion, because iron is more vivid than tin, and iron is maintained inside. But assuming that the tin layer is fixed together, because it is the anode of the primary battery, tin will cause iron to corrode faster.
Characteristics of galvanized iron: The surface of galvanized iron is not easy to rust. Commonly known as lead iron, tin iron. Why is it so difficult to rust? This is the iron on the surface of the repair effect layer, which is related to the assumption that the coating is damaged, and can also form an iron-zinc galvanic cell as the cathode maintenance principle of the special anode maintained by the anode, iron and iron.