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The effects of warm rolling reduction ratio ranging from 20% to 55% on microstructure evolution, the tensile deformation mechanism, and the associated mechanical properties of an Fe-30Mn-4Si-2Al TRIP/TWIP steel were studied. The warm rolling process resulted in the formation and proliferation of sub-structure, comprising dislocations, deformation twins as well as shear bands, and the densities of dislocation and twins were raised along with the increase in rolling reduction. The investigated steel, with a fully recrystallized state, exhibited a single ε-TRIP effect during the room temperature tensile deformation, on top of dislocation glide. However, the formation and growth of twin lamellae and ε-martensite were detected simultaneously during tensile deformation of the warm rolled specimen with rolling reduction of 35%, leading to a good balance between high yield strength of 785 MPa, good total ductility of 44%, and high work hardening rate. As the rolling reduction increased to 55%, the specimen revealed a relatively low work hardening rate, due to the high dislocation density, and dislocation glide was the main deformation mechanism. As a result, a tensile deformation mechanism that started from a single ε-martensitic transformation moved to a bi-mode of ε-martensitic transformation accompanied with deformation twinning, and finally to dislocation glide with the increasing warm rolling reduction was proposed.

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Soil heavy metal contamination caused by mining is a significant issue in China. The site of this study is located in Ganzhou of Jiangxi province in China. 102 soil samples were collected along the Yangmeijiang River. ICP-MS was used to obtain heavy metal concentrations in the soils. Significant contamination was found in the agriculture soils adjacent to the river and near mining industries. The heavy metal concentrations were high at depths of 20 cm and 40 cm. According to geo-accumulation index I geo , the soils were extremely polluted with Cd (I geo = 4-7), heavily polluted with As (I geo = 2-4), moderately to heavily polluted with Pb, Zn and Cu (I geo = 0-4) and virtually unpolluted with Ni, Cr and Hg (I geo = -3-1). These results may be a result of large amounts of As, Cd, Pb, Cu and Zn being produced by nearby copper heap leach facilities. Based on USEPA method for health risk assessment, with ingestion being the major pathway for health risks, heavy metals pose a non-carcinogenic risk to adults (HQ max = 2.87, CR max = 4.25 × 10 -4 ), but pose both non-carcinogenic and carcinogenic risk to children (HQ max = 20, CR max = 1.15×10 -3 ). Overall, As, Pb and Cr pose the primary health risks for the soils in the study area.