Research on Fabrication of TRIP Steel with High Durability

Many weapons and mechanical parts such as bullet shells, jet engine covers, bulletproof armor shells operated in harsh conditions require durability when used and good flexibility when forming. Many countries have used steel with phase transition effects due to plastic deformation - TRIP effect (Transformation Induced Plasticity) to replace low carbon steel, high-strength low-alloy steel fabricating them. The paper presents research on the technology of metallurgy of a CMnSiAl steel grade from sponge iron materials and application of mechanical-thermal technology to create small particles and organize three phases: Ferrite, Bainite, residual Austenite to stabilize and increase plasticity. The results show that the impurity content is low, S% is less than 0.025%; magnitude of small ferrite particles below 20μm, ratio of residual austenitic fγ = 6.39%. Mechanical properties: durable limit σb on 590 MPa, yield limit σc over 390 MPa, ratio σb/σc> 1.5 and relative elongation δ50 over 28%. Research results for the prospect of applying this steel grade in the manufacture of some defense products, instead imported materials.