Shot Peening: ZrO 2 Ceramic beads (Ø=300 μm, 700 HV) Almen intensity: 10A Coverage: 100% ↑ Resistance to: Fatigue SSC Fretting Erosion 0 200 400 600 800 1000 1200 1400 1600 0 100 200 300 400 500 Temperature [°C] Soaking time [s/mm] Thermal Treatment CD A36 A72 A210 A360 S1300 S1400 Solubilization Temperature Recrystallization Steps γ 2 Precipitation 0,25 0,5 0,75 1 1,25 1,5 1,75 CD A36 A72 A210 A360 S1300 S1400 Partition Coefficient Chemical Distribution Cr Mo Ni Mn 220 230 240 250 260 270 280 290 300 310 320 CD A36 A72 A210 A360 S1300 S1400 HV100 Phases MicroHV Ferrite Austenite ENERGY DISSIPATION MODES: 1D: Point defects Density – X-Ray Diffraction FWHM (↓S1400) 2D: N° of Twins / Area (↓S1400) 3D: Stress-Induced Martensite %Vol (↑S1400) SDSSs γ-Austenite α-Ferrite MAX HOMOGENEITY BEST TT: S1400 -700 -600 -500 -400 -300 -200 -100 0 10 20 30 40 50 MPa μm Residual Stresses Depth Profile CD - Ferrite S1300 - Ferrite S1400 - Ferrite A72 - Ferrite A360 - Ferrite 0,0 5,0 10,0 15,0 20,0 25,0 30,0 35,0 CD A36 A72 A210 A360 S1300 S1400 μm Surface Roughness Rmax Ra -1,25 -1 -0,75 -0,5 -0,25 0 0,25 CD A36 A72 A210 A360 S1300 S1400 [g/(mm^2*week)] Salt Spray Fog Test Thermal Treated - Δ Weight Shot Peened - Δ Weight 250 300 350 400 450 500 550 CD A36 A72 A210 A360 S1300 S1400 HV200 Surface HV Thermal Treatment Shot Peening Effect of preparatory thermal treatments on S32760 SDSSs properties after shot peening A.F. Ciuffini , A. Gruttadauria, S. Barella, C. Mapelli, I.F. Pariente C Cr Cu Fe Mo Mn N Ni W Min - 24 0,5 Bal. 3 - 0,2 6 0,5 Max 0,03 26 1 4 1 0,3 8 1 CD S1300 S1400 A36 A72 A210 A360