Effects Of Shot Peening On Hydrogen Resistance Of Metal Materials

In this paper,X80 pipeline steel and nickel-based 718 alloy are used as the research objects.Through slow tensile test,electrochemical hydrogen penetration test,combined with microscopic morphological characterization.The SP pressure,hydrogen charging conditions,strain rate were studied on the influence of the tensile properties of the X80 pipeline steel and nickel-based 718 alloy,and the electrochemical performance test was used to study the improvement of the material’s corrosion resistance by SP treatment.Both X80 pipeline steel and nickel-based 718 alloy showed significant performance degradation under hydrogen charging conditions.Under in-situ electrochemical hydrogen charging condition,the HE failure of the material is more serious.SP treatment suppresses the HE sensitivity of the material.With the increase of the SP pressure,the material’s HE sensitivity decreases first and then gradually increases.When the SP pressure is 0.3MPa,the material’s anti-brittle resistance performance the best.For the X80 sample,the elongation after fracture was increased by about 36.88%(in-situ electrochemical hydrogen charging)and 24.48%(pre-charged hydrogen),and for the nickel-based 718 alloy sample under pre-hydrogenation,the elongation after fracture was increased by about 15.12%.SP improves the corrosion resistance of X80 pipeline steel and nickel-based 718 alloy.With the increase of SP pressure,the corrosion resistance of the material shows a trend of increasing first and then decreasing.The pressure of 0.4 MPa works best.Nanostructure of the surface structure is the main factor to improve the corrosion resistance of the material,but as the pressure rises to 0.5 MPa,due to the large number of surface micro-cracks and defects,the corrosion resistance of the material is weakened.