1, dust

Production is often in dusty venues, often with a lot of air dust, they continue to fall on equipment surfaces. They can be removed with water or an alkaline solution. However, there is adhesion of dirt requires high pressure water or steam to clean up.

2, iron or embedded floating iron

On any surface free iron will rust and corrode the stainless steel. Therefore, it must be removed. IRES can generally be removed together with the dust. Some strong adhesion, must be embedded in the iron handle. In addition to dust, many sources of iron surface, including the use of ordinary carbon steel wire brush cleaning and shot peening with previously used on carbon steel, low alloy steel or cast iron through sand, glass beads or other abrasive, or near the stainless steel parts and equipment for non-stainless steel products mentioned were grinding. Hanging over the next material or process if we do not take measures to protect stainless steel wire rope, spreader and work surface iron easily embedded or stain the surface.

If rust test solution can not be fully cleaned, the surface is not recommended in the process of equipment that is used to produce direct contact with the surface of human consumption using this test method. Relatively simple test method is exposed for 12 to 24 hours in the water, check for rust. This test is poor sensitivity and time-consuming. These are testing, not the clean-up methods. If you find the presence of iron, it must be cleaned with a later introduction of chemical and electrochemical methods.

3, scratches

To prevent the process lubricant or product and / or dirt accumulates, the need for scratches and other rough surfaces are generally removed by mechanical cleaning of stainless steel for polishing machine. Hot temper color, and other oxide if the welding or repair stainless steel mill during the air is heated to a certain temperature, on both sides of the weld, the weld and the lower surface of the bottom will appear chromium oxide hot temper color. Hot temper color than the thin protective oxide film, and clearly visible. Color depends on thickness, may be in rainbow colors, blue, purple and brown to yellowish. Thicker oxide is black. It is due to due to high temperatures or long stay in the more highly. When any one of such oxide layer occurs, the metal surface of the chromium content will be reduced, resulting in reduced corrosion resistance of these regions. In this case, not only to eliminate hot temper color, and other oxide layers, they also deal with the following lean chromium metal layer to clean up.

4, rust

Pre-production or production process sometimes see rust on stainless steel products or equipment, indicating that the surface is seriously contaminated. The rust must be removed before the equipment off and put into use, the surface should be cleaned thoroughly checked by the iron test and / or water test.

5, coarse grinding and machining

Grinding and machining will result in a rough surface, leaving grooves, overlapping and burrs. Each defect may also damage the metal surface to a certain depth, so that the damaged metal surface can not be cleaned up by pickling, electro-polishing or shot (such as dry sandblasting, abrasive glass beads used) or the like. Rough surfaces can become corrosion and deposition product birthplace, before re-welding trimming or removing excess weld defects Strengthening do not use coarse grinding polished.

The effects of these pollutants affect similar oils and fats. We recommend washing with a clean brush and clean water or alkaline cleaning agents and can also be used high-pressure water or steam rinse. In the case of using the state to ferrite-based stainless steel. Chromium content of 11% to 30%, with a body-centered cubic crystal structure. Such steel is generally not contain nickel, it may also contain minor amounts of Mo, Ti, Nb until the element type of steel with a thermal coefficient of expansion coefficient, good oxidation resistance, excellent resistance to stress corrosion, are used for the manufacture Weathering , steam, water and oxidizing acid corrosion of components.

The existence of such steel plastic poor ductility and corrosion resistance after welding and other shortcomings significantly reduced, thus limiting its application.