Behavior Of Non-metallic Inclusions Research Articles

Study on the Behaviour of Nonmetallic Inclusions in High Carbon Chromium Steel

Study on the Behaviour of Nonmetallic Inclusions in High Carbon Chromium Steel

鋼の引張試験における介在物の挙動と疲労性質

In order to investigate the effects of non-metallic inclusions on the strength of steels, the behavior of non-metallic inclusions under tensile stress was studied by microscopic observations and the fatigue properties of several 3%Ni-Mo-V steels made by different processes were tested. The results were as follows: (i) At a slight excess load over the yielding point, microcracks are found at the corners of non-metallic inclusions, especially on the transverse specimen; (ii) between the elongated type inclusions, silicate is more harmful than sulfide to transverse fatigue properties; and this is borne out by the higher strain concentration evident at the silicate during tensile test; (iii) the effect of sulfide on fatigue properties does not exceed 10%, even though the sulfide content is rather high and vacuum-poured electric-arc furnace steel has good cleanliness and good fatigue properties; and (iv) the notched fatigue strength shows little anisotropy.