Toughness of old mild steels

Abstract

For the rehabilitation of steel structures from the 19th and the early 20th century the brittle fracture behaviour is essential for the structural safety. The methods of the assessment used in EN 1993-1-10 were predominantly developed for welded structures made of current steel grades with more or less high toughness. The check by limitation of the plate thickness (Table 2.1 in [1]) is not suitable for old mild steel structures with riveted and bolted connections. Notch effects and residual stresses are quite different to those ones of welded structures. The material properties of old mild steels are characterised by larger scatters, particularly due to the inhomogeneous distribution of tramp elements and higher contents of non-metallic inclusions. In this paper, experimental and analytical studies of the brittle fracture behaviour of mild steels as well as aging effects of structural elements with holes for riveted and bolted connections are presented (see also [2][3][4], [20]).

Economic and environmental assessment of high‐strength steel grades

“…Indeed, the relative ratios are inherently dependent on the base price. For sake of comparison, S235J2 is chosen as the reference steel because the latter was defined as reference by Stroetmann [15]. As can be seen in Figure 2, the established relative price relationships are validated by values reported by Stroetmann [15] and the other collected values.…”

“…For sake of comparison, S235J2 is chosen as the reference steel because the latter was defined as reference by Stroetmann [15]. As can be seen in Figure 2, the established relative price relationships are validated by values reported by Stroetmann [15] and the other collected values. Referring to a presentation by Stroetmann [29], it appears that the base price at the publication period (October 2010) was equal to 700€/t; it explains why the "Medium base price" curve corresponding to a base price of 750€/t is closer to the Stroetmann's relative prices.…”

“…Figure 2 reports both literature values respectively proposed by Johansson [14] and Stroetmann [15] for plates, some values from Ruukki [28] and a Belgian supplier for thermomechanical hot-rolled coils, and three evolutions computed through the cost estimation proposed in the present paper by considering three significantly different base price levels for hot-rolled coils: low level (500€/t), intermediary level (750€/t) and high-level (1000€/t). Indeed, the relative ratios are inherently dependent on the base price.…”

“…In this paper, investigations were focused on thermomechanically produced steels as this production process is more widely used to reach high-strength properties as it requires less carbon and alloy contents for better weldability than QT steels. The relative values established are compared with the literature, i.e., Johansson [14] and Stroetmann [15].…”

“…Concerning the relative prices as a function of yield strength, Johansson in 2005 [14] and Stroetmann in 2011 [15] gave relative values with reference to S235J2 material based on average market prices. Besides, Johansson derived an analytical function to predict these prices, which follows the square root of the yield strength.…”