In some areas, the soil is getting more and more acidic due to acids deposition. It is imperative to investigate the soil corrosion performance of underground structures. As soil is very complex, the corrosion investigation and understanding of soil buried structures are quite difficult. In this study, the corrosion performance of Q235 steel in simulated Yingtan soil solutions with pH 3.0, 4.0, 5.5, and 7.0 was investigated by weight loss test and electrochemical test including potentiodynamic polarization curves and electrochemical impedance spectroscopy, as well as corrosion process was discussed. All the tests indicated that the corrosion rate of Q235 steel in simulated soil solution was closely related to its pH value. The corrosion rate decreased with increasing pH from 3.0 to 7.0.

In the present paper, the effects of precompression along extrusion direction (ED) on subsequent compression perpendicular to ED were investigated in an extruded magnesium alloy AZ31. The results showed that the yield stress under compression perpendicular to ED increased if there was precompression along ED. The evolution of deformation mechanism was responsible for increase in yield stress because plastic deformation was dominated by both basal slip and {10–12} twinning under compression perpendicular to ED in samples without prestrain, but basal slip was difficult to be activated and {10–12} twinning dominated deformation in samples with precompression. However, because basal slip had no obvious contribution to plastic deformation, the ductility decreased if there was precompression along ED.

For extruded magnesium alloy, prior compression along extrusion direction has great influences in the flow stress during subsequent tension. Detwinning plays an important role for these influences. In the present study, the effects of different prestrains on strain hardening behaviour during subsequent tension were examined in an extruded magnesium alloy AZ31. The results showed that the existence of detwinning decreased the tensile yield stress. Samples with different prestrains exhibited different strain hardening behaviour during subsequent tension. The reorientation due to detwinning had a great effect on strain hardening during tension. In addition, the effect of detwinning on ultimate elongation was investigated. The results showed that the sample with higher prestrain always has higher ultimate elongation due to the contribution of detwinning on macroscopic strain.