Effect of controlled-rolling parameters on the ageing response of HSLA-80 steel

Abstract

Microalloyed steels containing copper in order to promote precipitation hardening are one of the approaches adopted to develop new materials with high mechanical strength but minimized carbon content to assure good weldability. Besides that, the thermomechanical processing of such alloys can eliminate the subsequent quench and tempering heat treatments required by conventional steels. The effects of controlled rolling parameters over the ageing response of an HSLA-80 microalloyed steel with 1.10% copper were studied in this work. The relatively weak influence over the ageing response verified when the reheating temperature was elevated from 1100°C to 1200°C indicated that copper precipitation is the main mechanism behind the hardening promoted by the ageing treatment; niobium had a secondary role. The strain degree applied during the roughing phase increased the ageing response of the alloy, but a increase in the strain degree applied during the finishing phase had no effect over this aspect. Also a finishing temperature variation did not affect significantly the ageing response of the HSLA-80 steel.

Microstructure and Mechanical Properties of X80 Induction Heating Bends

“…Results in this paper indicate that when the cooling speed is higher (20℃/s～ 30℃/s), the comprehensive properties such as strength and toughness of X80 induction heating bends are excellent. Hence under field conditions, the cooling speed is controlled by changing the cooling medium and its pressure or flow and cooling device, or by cooling at the same time both inside and outside the pipes when necessary, to make sure that there is enough granular bainite at the surface and the center of the bends, thus producing X80 induction heating bends with excellent strength and toughness [9,10]. (1) By using physical thermal simulation technology, effects of heating temperature on microstructure and mechanical properties of X80 induction heating bends were investigated.…”

Characterisation of strain-induced precipitation behaviour in microalloyed steels during thermomechanical controlled processing

“…Finally, the full recrystallisation time expressed as a function of the recrystallized volume fraction (X) was calculated using the Johnson et al model [17][18][19] and is given by Eq. (4).…”

Oxidation-Induced Cu Coating on Steel Surface

“…Copper can cause hot shortness problem in steels. On the other hand, copper is widely used in weathering steels, antibacterial stainless steels [1][2][3], biological steel materials [4] and some other steels such as HSLA [5][6][7], super 304H austenitic heat-resistant steel [8][9][10] and stainless steels [11][12][13] for its strengthening, corrosion resistance and antibacterial properties.…”