Tests on Low Temperature Characteristic of a 9% Nickel Steel

Abstract

This paper presents the test results which were carried out to examine suitability of a 9% nickel steel (quenched and tempered) for the materials of L.M.G. vessels. V-notch Charpy tests and ESSO tests were employed to investigate the fracture toughness at low temperature. Welded joints of the plates using Inconel type electrodes and austenitic stainless type ones were also tested. The results were obtained as follows : Brittle fracture did not initiate at a temperature of -190℃ or above, and also did not propagate at a temperature of -180℃ or above in the virgin plates of the steel. The critical temperatures of brittle fracture, however, were raised by annealing or other heat treatment. V-notch Charpy tests showed the lowest values at fusion zone of a weld, but no brittle fracture was produced by ESSO tests at a temperatures of -180℃ or above. V-notch Charpy values at low temperature were slightly decreased by plastic prestraining.