Papers by Author: Yu Chen

Abstract: Effects of continuous annealing process on microstructure and properties of Si based cold-rolled TRIP Steel were studied. The results show that the TRIP effect is more obvious on the condition of 800°C with 120s annealing process and 400°C with 520s aging treatment than others progress. The yield strength of the tested steel is 405MPa, tensile strength is 670MPa, elongation is 32% and strain hardening exponent is 0.230. The microstructures are ferrite, bainite and retained austenite and the volume fraction of retained austenite for the tested steel is 9.20%.

Abstract: By analysis of TWIP Steels with different manganese content, the results showed that the microstructures and properties had been changed with different Mn content. The elongation of the tested steel with 22.5% Mn was high for 55.5 % and n value of that reached to 0.360. When Mn content of the tested steel was 17.9%, the yield and tensile strength were higher and its elongation was lower for the tested steel than that of the tested steel with 22.5% Mn. The microstructures of the tested steel with high Mn content were austenite before and after being stretched at room temperature. Mn content was decreased and the microstructure of the tested steel after being stretched had a small amount of martensite transformation at room temperature. That is to say, double effect with TWIP and TRIP had occurred, but TWIP effect was dominant. TWIP effect increased plasticity and strain hardening capacity to improve formability. TRIP effect was mainly to improve strength so as to further attain the strength of the tested steel.