316 & 316L 1

[azizur447]

Anybody tell me why ASME II-D recommended for 316 Stainless Steel maximum temperature 1500F whereas for 316L 850F although 316L is superior quality. Only difference of these two type of steel are carbon content (.08 & .03 Max).

 

[SJones]

http://www.eng-tips.com/viewthread.cfm?qid=127107

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[gtaw]

Carbon is added to steels to make it stronger. Carbon steel, high strength low alloy steel, stainless steel, see the drift?

Best regards - Al

 

[jwhit]

The increased C content improves high temperature creep resistance.

 

[pandithan]

For high temperature service, creep strength is very important, to achieve creep strength carbon is require more to form carbides. L is having max carbon .03 and conventional with .08max

 

[Mechanimal]

You could use code case 2577 for section VIII division 1 which allows 316L up to 1200F.

 

[GenB]

You called it superior but it is superior to corrosion and not for strength.

 

[moltenmetal]

Most material is dual grade now- meeting both the bulk strength of 316 grade and the low carbon content of 316L grade, i.e. the alloy does not rely on the bulk strength afforded by the carbon content. Where the minimum carbon content comes into play is for creep resistance at high temperatures, as mentioned by other posters. In high temperature services, the chromium depletion due to chrome carbide formation in the 316 and 316H grades is not an issue for corrosion resistance- but it IS an issue if the material is brought down in temperature and exposed to aqueous corrosion conditions. However, at high temperatures, there is little if any benefit in using 316H versus using 304H, so the latter is the more common alloy.