Computers OverClocked Forums Computers OverClocked
"Not just another computer help website."

FAQ Search Upgrade Register
Favorite Threads Private Messaging Login

Menu
Forums
RegisterRegister
Over Clocking Guide
Over Clocking Help
Computer Building Help
Virus/Security Alerts
Broadband Tweaks
Computing Guides
Featured Hot Deals
Reviews
Tools


Top 25 reasons to register!

Advertise your link here for $19.99/month!

 
 Computers OverClocked Welcomes You!
 Date/Time is Thu Jul 19, 2018 5:39 am
 Computer Photo Gallery
Computing News Headlines:
New HTC Android Phones Tweaked to Evade Apple Patents
Ivy Bridge Temperatures – It’s Gettin’ Hot in Here
Adobe CS6 on sale today, Creative Cloud coming May 11th

Stress corrosion on the surface of stainless steel pipe
Post new topic Reply to topic Computers OverClocked Forums - The General Store All times are GMT - 5 Hours - EDT
Author Message
yaangcom
Member



User is offline 
Send private message
Joined: Apr 26 2016
Posts: 395

PostPost subject: Stress corrosion on the surface of stainless steel pipe
Posted: Sat Jul 07, 2018 7:32 pm
Reply with quote

When the stainless steel pipe is used for a long time, some oxidation phenomena will appear on the surface of the pipe. Good maintenance is only the extension of the oxidation. So why does the surface of the stainless steel pipe appear to be oxidizing?
In fact, these surface oxidation is caused by corrosion of stainless steel pipes. The causes of corrosion on the surface of stainless steel pipe are mainly in the following aspects.
One is that when the stainless steel pipe is in chlorine containing medium, the passivation film on the surface of the material is particularly vulnerable to destruction, which is due to the high potential energy of chlorine oxidation. Most of the time, the surface passivation layer of stainless steel pipe will be destroyed only in some areas, which is manifested by corrosion, forming tiny holes or pits, and this corrosion is often referred to as point corrosion. The rate of point corrosion increases with the increase of temperature, and increases with the increase of medium concentration.
The corresponding solution is to use stainless steel passivation solution at room temperature for half an hour, which can significantly increase the corrosion resistance of stainless steel pipes about 5 to 20 times. The stainless steel passivation solution can be used circularly, and it is also easy to operate, which can greatly reduce the production cost.
The second aspect is that the passivation layer on the surface of the stainless steel pipe is also easily damaged when the stainless steel pipe is produced and welded. When the heating temperature and time of welding in the production of stainless steel sensitization temperature (about 425-815 DEG C) area, chemical composition of stainless steel in the supersaturated carbon will first precipitated at the grain boundaries, and combined to produce the chromium carbide and chromium, and this time of carbon in austenite in the diffusion speed in chromium diffusion rate, leading to not because of formation of chromium carbide and loss of chromium in the chromium content of grain, grain boundary precipitation of chromium carbide with results continuously decreases rapidly, produce the chromium depleted zone, thereby reducing the corrosion resistance of the passivation layer. When the medium chlorine and other corrosive medium contact, it will cause the micro battery corrosion. Although corrosion occurs only on the surface of grain, it will rapidly penetrate into the intergranular corrosion of the organization, and the stainless steel pipe will be particularly prominent in the welding area.
The third aspect is the stress corrosion crack. In a simple way, the stress in the stainless steel pipe is influenced by the joint effect of the crack embrittlement. But the environment that causes this situation is generally very complex. Not only light is tensile stress, but also the resultant force of residual stress produced in the production, welding, or processing of the stainless steel.
Source: China Stainless Steel Pipes Manufacturer - Yaang Pipe Industry Co., Limited (www.yaang.com)
Back to top
 Rate Post
View previous topic :: View next topic  
Post new topic Reply to topic Computers OverClocked Forums - The General Store Page 1 of 1


Similar Topics
Topic Author Forum Replies Posted
No new posts characteristics of stainless steel se... yaangcom The General Store 0 Tue Jul 17, 2018 10:00 am View latest post
No new posts Two forms and application examples of... yaangcom The General Store 0 Mon Jul 16, 2018 10:34 am View latest post
No new posts surface treatment process for stainle... yaangcom The General Store 0 Sun Jul 15, 2018 10:09 am View latest post
No new posts Strength difference of various kinds ... yaangcom The General Store 0 Wed Jul 11, 2018 7:50 pm View latest post
No new posts magnetic properties of austenitic sta... yaangcom The General Store 0 Wed Jul 11, 2018 5:46 am View latest post