PSI - Issue 14

Manojakumar Chimmat et al. / Procedia Structural Integrity 14 (2019) 746–757

755

Author name / Structural Integrity Procedia 00 (2018) 000 – 000

10

Distorted

Fig. 13. Image showing distorted CoCrMo Coupon

3.3 Residual stress on as printed and heat treated SS316L Cube

Figure 14 shows the variation of residual stress on as printed and heat treated SS316L Cube. All the surface stresses are tensile in the as printed condition, with the top most surface showing a maximum tensile stress of 127 MPa. The maximum value of the residual stress built up in the part is much below that of the yield strength. All the sides of the SS316L Cube measured nearly ~60-85 MPa in the as printed condition and bottom surface shows little higher stress because it was an EDM cut face. Upon heat treatment, residual stresses in the Cube are relieved and resulted in the almost zero stress on all surfaces.

100 150 200 250

0 50

Top Bottom XZ YZ

Residual stress (MPa)

As printed Heat treated 650°C

Fig. 14 Residual stress on, as printed and heat treated SS316L Cube

Table 4 Comparison of residual stress of CoCrMo and SS316L in the as printed and heat treated condition with the yield strength

Residual stress (MPa) Top Side

Yield strength (MPa)

Heat treated temperature

Alloys

Condition As printed Grit blasted

1100 (Bawane et al. 2018)

265

130

-300

CoCrMo

950°C 1050°C 1150°C

600 (Bawane et al. 2018)

246

120

Heat treated

-250

-140

600 (Kumar et al. 2018) 420 (Sudarshan et al. 2018)) 340 (Sudarshan et al. 2018)

10

7

As printed Heat treated

127

70 45

SS316L

650°C

93