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Martensitic transformation can be induced by plastic deformation in metastable iron-based alloys, such as stainless steels containing limited amounts of C, Ni and Cr. This transformation takes place at the temperature range from M s and M d , usually at relatively lower temperature values. The transformed martensite has been associated with maximum ultimate strength and relatively high ductility. In the present work, the tensile fracture characteristics of a metastable AISI type 302 stainless steel was investigated in the range of temperatures from -196°C to 25°C. Mechanical properties were compared to those of a stable AISI type 310 austenitic stainless steel. It was found that in 302 steel, its high degree of metastability and dilute dispersion of inclusions result in higher strength and complex modes of fracture, one of which consisting of martensite surrounding globular inclusions.

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The present work compares the tensile properties of polyester and epoxy matrix composites reinforced with hemp fibers. Polyester and epoxy reinforced with different volume fractions of hemp fibers up to 30% were prepared according to ASTM D-638-14 and tensile tested. The epoxy matrix composites reinforced with 30% of fibers presented tensile strength of 53 MPa, while those of polyester matrix, 25 MPa. The elastic modulus of the epoxy matrix composites was 1.75 GPa and that of the polyester matrix 4.05 GPa. The tests showed that the resistance of the epoxy composites reinforced with hemp fiber is superior to those of polyester matrix. However, the stiffness of the polyester/hemp fiber composites is higher than the epoxy/hemp fiber ones.