I would like to know which is the the EN standard of the material 1.4542 (known as 17-4-PH) in which appear its yield strength according to the rise in temperature.
Grade 1.4542 appears in the European standard EN 10088-3. This standard shows the yield strength requirements for 1.4542 in four different heat treated conditions (+800, +930, +960, +1070) at the following temperatures:
Note that the designation 1.4542 will be found in various EN standards depending on the product form. For example:
EN 10088-3 covers semi-finished products, bars, rods, etc.
EN 10088-2 covers sheet, plate and strip.
EN 10028-7 covers sheet, plate and strip.
There may be others.