Development of High Strength and Plasticity TRIP Seamless Steel Tube and Investigation of Its Hydroformability

The proved manufacturing technique of the TRIP steel is employed for steel tube production,and thus,a type of light-wall seamless tube in this steel and with a microstrucuture of ferrite,bainite,retained austenite as well as minor martensite is successfully developed.And its mechanical properties and hyrauformability are investigated via conventional tensile test,pipe-end flaring test,ring tensile test and hydraulic free bulge test.As a result,it is identified that the TRIP steel-made seamless tube as developed exhibits excellent axial and circum-ferential mechanical properties as well as good hydroformability,being worth using in the hydroforming field.