Productive Trial Research About The Hot Rolling Strip Steel HP295

The works of this paper were carried out integrating with Jigang Steel production innovation project "Development of at 2006. Pre-production and systematic analysis were proceeded, By the thermal simulation experiments and the laboratory rolling experiments, the rule of the effects of different cooling styles on yield ratio were studied and on this basic, suitable temperature and cooling style were determined. The main works of this paper involved as follows:(1) Small-lot HP295 was produced on ASP 1700 hot rolling strip production line. It was found that the component of C:0.13%-0.19%, Si≤0.05%, Mn:0.7%-0.9% were suitable, the design of low carbon, low silicon and suitable manganese could satisfy the request of the strength and the plastic property., The percent of pass of the component was 100%, the steel was pure and the control of smelting and continuous metal cast processes were suitable; the yield ratio was a little higher though it satisfied the request. The yield ratio could be decreased and the plastic property could be improved by the optimization of the finish rolling temperature, the coiling temperature and the process of anterior stage cooling.(2) The rolling temperature and the cooling style were studied by thermal simulation experiments. CCT curve of HP295 was constructed through thermal expansion method.The strength and the plastic property of the steel could satisfy the request when finish rolling temperature was about 860℃;the content of ferrite increased and the grains refined when coiling temperature was 660℃, the distribution of the pearlite was more dispersive. Compared with anterior cooling stage style, posterior stage cooling style and two stage cooling style could obtain the microstructure with more ferrite and more refined grains.(3) The hot rolling experiments with different coiling temperature and cooling style were studied when the finish rolling temperature was 860℃.The results show that proper...