Numerická analýza příčné trhliny v bramě

Numerical analysis of a transversal crack in a steel slab

článek ve sborníku ve WoS nebo Scopus

en

This paper deals with the causes of a transversal crack in a steel slab with a 1300x145 mm cross-section by means of two numerical models. Samples were taken from and around the crack in order to analyze the concentration, as well as the chemical heterogeneity of the constituent elements and impurities. Simultaneously, the concentration of elements at the surface of the crack was measured after the crack was opened. The heterogeneity of elements was analyzed by the JEOL JXA 8600/KEVEX device. The measurement results were processed using mathematical statistics. The chemical heterogeneity of elements in the steel matrix around the crack, and at the crack surface, had been evaluated with the help of heterogeneity parameters, i.e. the arithmetic mean of concentration, the standard deviation of concentration and the index of heterogeneity of the analyzed elements. The results proved that there was an internal crack initiating immediately below the solidus temperature and consecutively propagating.

Tento článek se zabývá příčinami příčné trhliny v bramě (příčný řez o rozměrech 1300x145 mm) pomocí dvou numerických modelů. Vzorky byly odebrány z trhliny a jejího okolí tak, abychom analyzovali koncentrace konstitutivních prvků a příměsí pro zjištění chemické heterogenity. Současně, byly měřeny koncentrace prvků na povrchu trhliny po jejím rozevření. Heterogenita prvků byla analyzována na měřícím komplexu JEOL JXA 8600/KEVEX. Výsledky byly podrobeny statistické analýze. Byly vypočteny různé parametry heterogenity např. indexy heterogenity, průměrné koncentrace, standardní odchylky pro vzorky odebrané z okolí trhliny, povrchu lomu apod. Výsledky prokázaly že vnitřní trhlina vznikla hned po překročení solidu při chladnutí a pak se dále šířila.

This paper deals with the causes of a transversal crack in a steel slab with a 1300x145 mm cross-section by means of two numerical models. Samples were taken from and around the crack in order to analyze the concentration, as well as the chemical heterogeneity of the constituent elements and impurities. Simultaneously, the concentration of elements at the surface of the crack was measured after the crack was opened. The heterogeneity of elements was analyzed by the JEOL JXA 8600/KEVEX device. The measurement results were processed using mathematical statistics. The chemical heterogeneity of elements in the steel matrix around the crack, and at the crack surface, had been evaluated with the help of heterogeneity parameters, i.e. the arithmetic mean of concentration, the standard deviation of concentration and the index of heterogeneity of the analyzed elements. The results proved that there was an internal crack initiating immediately below the solidus temperature and consecutively propagating.

analysis, crack, steel slab

2006

01.04.2006

Tanger Ostrava, VŠB TU Ostrava

Tanger Ostrava, VŠB TU Ostrava Keltičkova 62, 710 00 Ostrava

80-86840-15-8

Teorie a praxe výroby a zpracování oceli

1

18–24

7