Investigation of Stress Concentration and Casing Strength Degradation Caused by Corrosion Pits

Table 2

Double pits stress concentration factor of steel (calculated).

Category	Center distance ratio	Outer edges			Pits bottom			Junction
				Average			Average
Single pit	0	1.10	1.09	1.09			1.75		1.75
Double pits	1	1.56	1.49	1.52	2.04	2.04	2.04	2.17	2.17
	1.5	1.58	1.56	1.57	2.19	2.14	2.17	2.56	2.56
	2	1.40	1.37	1.39	2.01	2.02	2.02	2.52	2.52
	3	1.36	1.31	1.34	1.85	1.92	1.89	1.18	1.89