Conditions for Obtaining a Good Set of Properties for Low-Carbon Microalloyed High-Strength Steels Clad with Corrosion-Resistant Austenitic Steels

Resumo

Conditions are studied for preparation with temperature and deformation treatment of a good set of mechanical properties and high quality rolled product characteristics for low-carbon Ti–Nb–V- and Mo–Timicroalloyed high-strength steels, clad with austenitic class corrosion-resistant chromium-nickel steels. It is established that an increase in uniformity of deformation for layers of a two-layer workpiece for steels of these types is facilitated by an increase in heating temperature and for the end of rolling to 1250 and 900°C, respectively. In order to provide good process ductility of corrosion-resistant austenitic steels in this temperature range, their chemical composition should satisfy a condition Cr_equ/Ni_equ not more than 1.5–1.6. On the basis of modeling results of hot rolling in a Gleeble 3500 unit and a laboratory duo 300 rolling mill, it is shown that with the use of a high temperature for workpiece heating and for the end of rolling it is possible to achieve good strength properties (ultimate strength more than 850 MPa) for lowcarbon Ti–Nb–V- and Mo–Ti-microalloyed steels. Test results for clad rolled product prepared from four two-layer workpieces with a different combination of steels in layers points to the achievement not only of high strength for low-carbon microalloyed steels of one layer, but also other mechanical properties, and also high quality layer joint properties.