This paper provides an overview on obtaining low-carbon ultra-fine grained dual-phase steels through rapid intercritical annealing of cold-rolled sheet as improved materials for automotive applications. A laboratory processing route was designed that involves cold-rolling of a tempered martensite structure followed by a second tempering step to produce a fine grained aggregate of ferrite and ca...

In the contribution the stress of die materials of thermal fatigue is defi ned and material life is derived theoretically and compared with the measured values. The important properties of the die materials as thermal conductivity, coeffi cient of thermal expansivity, modulus of elasticity and mechanical properties are described. Binding to it single die materials as carbon steels and chrome-tu...

Modern TRIP assisted steels contain retained austenite with carbon concentrations in excess of 1 wt-%. Some of their mechanical properties, in particular the toughness and ductility, rely on the diffusionless transformation of this austenite into high-carbon martensite, induced by stress and strain. The properties can be excellent in spite of the fact that freshly formed high-carbon martensite ...

Micro-alloyed High Strength Low Alloy steels (HSLA-steels) are widely used in civil construction, automobile and line pipe applications. They contain small quantities of alloying elements between 0,01 – 0,1 wt%, such as Niobium, Titanium, Vanadium, Aluminium and Nitrogen. These steels rely on thermo-mechanical rolling, a technique that simultaneously provides high strength, excellent toughness ...

Very often, in order to optimized welded constructions, some of their parts are made of heterogeneous steels. For example, microalloyed steels are in use for cars chassis making and high alloyed steels for different constructions making. From that reason, it’s not rare to find welded joints between ferrite microalloyed and austenitic highalloyed steels. As a rule, these joints are welded by usi...

Exposure tests were performed on low alloy steels in high Cl- and high SOx environment, and the structure of the rust were analyzed by TEM (Transmission Electron Microscopy) and Raman Spectroscopy. In the exposure test site, the concentrations of Cl- and SOx were found to be high, which caused the corrosion of the steels. The conventional weathering steel (SMA: 0.6% Cr-0.4% Cu-Fe) showed higher...

3 IMR KINKEN Research Highlights 2012 IMR KINKEN Research Highlights 2012 To reduce the fuel consumption by automobiles, medium carbon steels for forging parts, such as shafts and connecting rods, must be further strengthened. When carbide-forming elements such as Ti, Nb, and V, are alloyed with carbon steels, a fine dispersion of alloy carbides and large precipitation hardening can be achieved...

effect of small al additions, from 0.14% to 0.31% ai, on the hot deformation behavior of low carbon steels containing 1%cu-1.2%mn was investigated in the temperature range of 750-800•c over the strain rate range of 1o.3.1o.1s•1 by a hot compression testing machine. the flow curves obtained, exhibited typical characteristics of dynamic recovery type of softening mechanism, and the critical strai...

Austenitization is an inevitable occurrence during the heat treatment of steels. Despite this consideration, less attention has been paid so far to the study of the formation of austenite as compared with the vast amount of research on its decomposition. That is because the steel properties depend basically on the transformation processes following austenitization. However, the initial austenit...