Following the 1st report, we have performed the ring-shaped tube impact tensile test of cold drawn, seamless steel tubes, in order to study some characteristics on the impact strength of tangential direction of small-diametral and thin-walled steel tubes.
As the cold drawn tubes have many fiber structures in the direction of drawing, it generally seems that the resistance to impact load in the logitudinal direction differs from that in the tangential direction of tube. But the results obtained through this test have a similar tendency to the case of notched tube impact bending test, mentioned in the 1st report.
The different point from the results of impact bending test is that the impact tensile strength gets a little larger as test temperatures become lower than 100°C and has a maximum value at the temperature of -60°C or -100°C.