Open AccessExpress evaluation of welded joints cool resistance
Author(s) -
V. M. Matyunin,
A. Yu. Marchenkov,
M. A. Karimbekov,
А. Н. Демидов,
П. В. Волков,
N. Abusaif,
E. I. Geraskin,
D. A. Zhgut
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/759/1/012016
Subject(s) - materials science , brittleness , welding , indentation , metallurgy , alloy , composite material
Low-temperature instrumented indentation tests of welded joints are carried out. The effect of metal cooling on indentation diagrams and metal hardness is investigated. Impact strength tests with a gradual decrease in temperature with the identification of the cold brittleness threshold and determination of the critical brittleness temperature for several structural steels are performed. For an express evaluation of a metal cold resistance, the parameter γ is proposed, which is equal to the ratio of hardness at a given low temperature to hardness at room temperature. The relation between the parameter γ and the temperature coefficient of hardness, which is included in the equation describing low-temperature dependence of hardness, is established. For several grades of carbon and alloy steels, the relation between the parameter γ and the critical brittleness temperature T 0.4 , determined by the criterion value of impact strength KCV = 0.4 MJ/m 2 , is established. For welded joints obtained by electron beam welding and arc welding, the values of T 0.4 are determined by the parameter γ in various local zones, including parent metal, heat-affected zone and weld metal. The possibility of establishing the acceptable operation temperature of welded joints using the obtained distributions of the critical brittleness temperature T 0.4 is shown.