PSI - Issue 60

B Shashank Dutt et al. / Procedia Structural Integrity 60 (2024) 471–483 Author name / StructuralIntegrity Procedia 00 (2019) 000 – 000

476

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3.2 Estimation of fracture resistance

An attempt was made to estimate K 1c from tensile properties of SS 316 LN welds. Estimation of K 1c was carried using equation 3 and based on previous model by Baskes (1975). Modulus of toughness (I) was estimated using equation 4. Equation 4 was previously used for various types of steels (Oh 2022)

2

EI

K



(3)

2

(1

)

1

c

 

Where E = Youngs Modulus, I= modulus of toughness determined from area under stress- strain curve, ν = Poissons ratio (0.3)

) ( YS UTS 

(

 )

I



(4)

2

Where I = Modulus of toughness, YS = yield strength, UTS = ultimate tensile strength, ϵ = total elongation (%)

440

400

as weld aged 370 aged 475 aged 550

Tested at RT

a

as weld aged 370 aged 475 aged 550

b

J Tested at 380 C 1c

280 Fracture toughness, kJ.m -2 320 360 400

150 Fracture toughness, kJ.m -2 200 250 300 350

J 1c

240

100

Aging duration, h

Aging duration, h

300

as weld aged 370 aged 475 aged 550

c

J 1c

Tested at 550 C

150 Fracture toughness, kJ.m -2 200 250

100

Aging duration, h

Fig.5. Fracture toughness of SS 316 LN welds tested at (a) RT; (b) 380 °C; (c) 550 °C.