The effects of solution temperature on the microstructure and mechanical properties of 16-5 martensitic stainless steel were investigated by optical microscope（OM）

scanning electron microscope（SEM）

ThermoCalc

X-ray diffraction（XRD）

Rockwell hardness tester

universal material tensile tester

pendulum impact tester.The results reveal that the microstructure of the 16-5 martensitic stainless steel is composed of martensite and ferrite.With the solution temperature increasing

the amount of ferrite is increased

and tensile strength and elongation of the 16-5 martensitic stainless steel are increased firstly and then decreased

menahwile

impact energy of the stainless steel is decreased firstly and then increased.The tensile strength

elongation and impact energy reach the maximum values at 1 050℃

1 100℃

and 1 170℃

respectively.Ferrite can coordinate deformation and absorb shock load in martensitic stainless steel

however the increase of ferrite would play the role of seperating the matrix.