High temperature Stainless Steel Pipes maintain their mechanical properties when exposed to elevated temperatures on either a short- or long-term basis.All materials selection must be determined by the application and operating conditions in each individual case.
With their increased concentration of chrome, silicon and aluminium they are especially resistant under the influence of hot gases as well as in salt and metal melting. However, the individual corrosion resistance is always dependent on the surrounding conditions, and can therefore not be precisely determined in a single testing.
Besides the common Austenitic High Temperature Alloys above (i.e., 1.4948, 1.4878,1.4828, 1.4833, and 1.4845), there are three proprietary Stainless steel alloys: 153 MA, 253 MA, and 353 MA. These three Stainless steel alloys are based on the same concept. Improved oxidation resistance by an increased silicon content and addition of very small quantities of rare earth metals (micro-alloying => MA). Enhanced creep strength due to increased contents of nitrogen (and carbon for 253 MA). In many cases, theproperties of these steels have proved to be equivalent or even superior to those of grades with higher contents of alloying elements. 153 MA is normally intended for use at somewhat lower service temperature than the other two grades.
Depending on the area of application these temperatures can rise e.g. to
– 500°C (932°F) in chemical processes
– 700°C (1,292°F) in power plant applications
– 1,000°C (1,832°F) for furnace engineering
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)