Numerical data on creep-resistant steels. Part I

The steels required to resist creep are not defined by a specific standard. They appear in various standards such as :

• NF EN 10028; flat steel products for pressure vessels (parts 1, 2, 7);

• NF EN 10273, hot-rolled bars of weldable steels for pressure vessels; with specified high-temperature properties;

• NF EN 10222; forgings for pressure vessels ;

• NF EN 10216; seamless steel tubes for pressure service ;

• NF EN 10269; steels and nickel alloys for fasteners used at high and/or low temperatures;

• NF EN 10095; refractory steels and nickel alloys.

It goes without saying, therefore, that the user should refer to the standard defining the grade to find out all its specific features for the use in question, as the same grade may meet different requirements from one standard to another.

The following files and will therefore essentially be a compilation of the numerical data available in these standards, presented in the form of tables, each corresponding to a well-defined grade (and sometimes product). Each table recalls the basic characteristics (chemical analysis, tensile properties), the guaranteed values for hot yield strength (insofar as these are imposed) and the creep resistance characteristics, all of which have been compiled to materialize the field of use of the steel in question. At different temperatures, the most common examples are :

• unit loads causing 1% creep elongation in 100,000 hours, considered to be the lower limits of the working range;

• unit loads causing creep failure in 10,000 hours, considered as the upper limits of the working range.

In the absence of some of these data, reference was made to unit loads causing creep failure in 200,000 hours, considered as another lower limit of the working range.

Additional data, consisting of extracts from Japanese works, are provided in the file. .

The presentation of the different shades takes into account some of their particularities, which lead us to classify them into five categories:

— unalloyed steels: steels for which none of the limits specified in the table below is exceeded. ;