Physicochemical and Vibration Analysis of Christmas Tree Four-Way Flange Failure under Fracturing Process

Table 4

Testing results of bolt tensile properties.

		Yield strength (YS0.2) (MPa)	Tensile strength (MPa)	Percentage reduction of area (%)	Elongation (%)
Bolt type HD L7	Measurement no. 1	937	1044	63	21.5
	Measurement no. 2	954	1050	64	21.0
	Standard requirement	≥725	≥860	≥50	≥16
Bolt type LL B7	Measurement no. 1	1059	1119	61	19.5
	Measurement no. 2	1021	1093	61	18.5
	Standard requirement	≥720	≥860	≥50	≥16
Bolt type B7	Measurement no. 1	907	995	63	22.5
	Measurement no. 2	876	969	62	20.5
	Measurement no. 3	908	994	63	20.5
	Standard requirement	≥720	≥860	≥50	≥16