It has made a detail description about the strain and stress distribution of the cast shell in hydrostatic pressure

which was tested by electric measurement.The results indicate that all pressurestress relationships exhibits linear correlation under the standard pressure

so the casting shell is in elastic deformation and in trace residual strain with absence of yield deformation.Tested results show that the three points with the bigger stress are located at the intersecting line of the shell

and the overall stress distribution of the shell is consistent with the theoretical analysis.The strength evaluation shows that the shell casting technology is reasonable and the shell strength meets completely the demands of safety design.Finally

the analyzed results of shell stress and the fracture structure reveal that the fracture mechanism is characterized by mixing of brittle fracture and plastic fracture

and the micro-porosity in metallurgical structure is still the resource of the fracture with the increase of the stress.