History To an incredible big degree stainless welded steel pipes are utilized simply because of the corrosion resistance of their surfaces. This great corrosion resistance can only be accomplished if correct washing and finish procedures are carried out soon after any fabrication procedure which has weakened the surface problem.
Passivation This procedure is suggested exactly where the surface should be free of cost of Steel. The presence of any steel, cast steel, mild steel, carbon steel or reduced alloy steel particles on the surface of stainless steel will advertise pitting corrosion at the cells arranged up among the "free of cost" steel and stainless steel. This potentially incredible real serious (and definitely invisible) Issue most generally takes spot anticipated to contamination by scraping with carbon steel resources or fixtures, or from grinding swarf. Passivation also assists in the quick progress of the passive surface layer on the steel.
Be aware: 1. We should carry out a trial surface treatment in advance if no dulling of the steel surface can be tolerated. 2. All passivation treatment should be done after rinsing it completely. 3. Observe all precautions for managing acids - nitric acid is extremely corrosive and hazardous to subjected dermis.
Pickling Pickling is an acid remedy to eliminate large temperatures scale enveloped in welding, heat remedy or warm functioning. It also eliminates red-colored rust from corrosion of the steel or from corrosion of contaminant steel or steel particles. Be aware that passivation is not sufficiently aggressive to eliminate this corrosion Item soon after the free of cost steel has begun to rust. High temperatures dim scale is not only undesirable for aesthetic causes - it also leads to a reduced corrosion resistance of the underlying steel surface layer.