What should I do about the damage to the stainless steel wire mesh surface?
Stainless steel wire mesh is used for screening and filtration under acid and alkali environmental conditions. The petroleum industry is used as a mud network, chemical chemical fiber industry, as a sieve mesh and electroplating. So what about stainless steel surface damage?
1. Floating iron powder or embedded iron
On any surface, free iron rusts and corrodes the stainless steel. Therefore, it must be cleared. Floating powder can generally be removed with dust. Some adhesion is very strong and must be treated as embedded iron.
In addition to dust, there are many sources of surface iron, including cleaning with ordinary carbon steel wire brushes and shot blasting with sand, glass beads or other abrasives previously used on plain carbon steel, low alloy steel or cast iron parts, or The aforementioned non-stainless steel products are ground near stainless steel parts and equipment. Wire ropes, spreaders and iron on the work surface can easily embed or smear the surface if the stainless steel is not protected during the blanking or lifting process.
2, dust
Production is often done in dusty areas, often with a lot of dust in the air, which constantly land on the surface of the equipment. They can be removed with water or an alkaline solution. However, adhering dust requires high pressure water or steam for cleaning.
3, rust spots
Stainless steel products or equipment are sometimes rusted before or during production, which indicates that the surface is heavily contaminated. The rust must be removed before the equipment is put into use. The thoroughly cleaned surface should be inspected by iron test and/or water test.
4, scratches
In order to prevent the accumulation of process lubricants or products and dirt, mechanical cleaning of scratches and other rough surfaces must be carried out with a special stainless steel polishing machine. Thermal tempering and other oxide layers if welding or grinding The medium-sized stainless steel is heated to a certain high temperature in the air, and the chrome oxide thermal tempering color appears on both sides of the weld, the lower surface of the weld, and the bottom.
The thermal tempering color is thinner than the oxidized protective film and is clearly visible. The color depends on the thickness and can be seen in rainbow, blue, purple to pale yellow and brown. Thicker oxides are generally black. It is due to staying at a high temperature or for a long time at a higher degree. When any such oxide layer is present, the chromium content of the metal surface is reduced, resulting in reduced corrosion resistance in these areas.
5, welding splash
Welding spatter has a lot to do with the welding process. For example: GTAM (gas shielded tungsten arc welding) or TIG (inert gas shielded tungsten soldering) does not splash. However, the use of GMAW (gas-shielded metal arc welding) and FCAW (arc welding with flux core) welding process can cause a lot of splash if the welding parameters are used improperly. When this happens, the parameters must be adjusted. If you want to solve the problem of welding spatter, apply anti-splash agent on each side of the joint before welding, which can eliminate the adhesion of spatter. This anti-splash agent and various spatters can be easily removed after soldering without damaging the surface or causing minor damage.
6, welding arc marks
When the welder ignites the arc on the metal surface, it will cause surface roughness defects. The protective film is damaged, leaving a potential source of corrosion. The welder shall ignite the arc on the welded bead or on the side of the weld joint. The arcing trace is then melted into the weld.
7, residual adhesive
When the tape and the protective paper are torn off, a part of the adhesive remains on the stainless steel surface. If the adhesive is not yet hard, it can be removed with an organic flux. However, when exposed to light and air, the binder becomes hard and forms a source of corrosion for crevice corrosion. Mechanical cleaning is then required with fine abrasives.
8, flux
The welding process using flux is manual welding, flux core arc welding and submerged arc welding. These welding processes leave fine flux particles on the surface, which cannot be removed by ordinary cleaning methods. This particle will be the source of corrosion for crevice corrosion and must be removed by mechanical cleaning.
PREVIOUS： Application of plain weave stainless steel wire mesh in flat screen printing
