Abstract. The temperature variations caused by additive tectonic stress has been studied to explain its relationship with the seismic fault sliding of the Abruzzo M = 6.3 Earthquake in April 2009. According to the periodic changes of the additive tectonic stress caused by the celestial tidegenerating force, the temperature variations before and after the earthquake have been analyzed based on the temperature data from National Centers for Environmental Prediction (NCEP). The figures of temperature variations clearly show that the abnormal increasing of the temperature has resulted from seismic fault sliding. Based on this method, it is possible to forewarn short-impending earthquakes.

In this paper, we studied the effect of decarburization layer thickness and carbon content on the ultimate cold bending angle of the hot stamping steels. The ultimate cold bending angle of hot stamping steel with 0.23 (wt. pct) carbon content and 0.35 (wt. pct) carbon content is compared. With the increase of carbon content, the ultimate cold bending angle decreases from 66.1°to 40.8°. The appearance of a completely decarburized layer in the microstructure will significantly increase the ultimate cold bending angle, from 66.1°to 77.4°. It can be found that carbon content is key factor affecting the ultimate cold bending angle of hot stamping steels, the thickness of the decarburized layer is another key factor affecting the ultimate cold bending angle of the hot stamping steels.