Papers by Author: Fang Yi Sun

Abstract: The effect of different annealing temperature on microstructure and properties of the hot-stamping boron steel were studied.The results show that the yield strength of the test steel is reduced with increasing annealing temperature, only at 790°C,the specimen yield strength increased slightly, and showed a significant downward trend after 790°C.The specimen tensile strength and hardness with the change of the same trend when annealing temperature changes.And through the test we can see,at 760°C ,the test steel has entered a two-phase region,the test steel gain ferrite and pearlite when it is annealed below the temperature,it is easy to appear martensite microstructure when it is annealed in the higher temperature,and lead to the strength and hardness of the rise.

Abstract: The relationship between texture and secondary work embrittlement of interstitial-free steels was studied by X-ray analysis technique and scanning electron microscopy analysis technique. The results indicated that the stronger the γ fiber texture was, the higher the plastic strain ratio (r-value) was, and Secondary work embrittlement temperature rose as r-value increased or γ fiber texture intensified. The mode of secondary work embrittlement fracture was a blend of cleavage fracture and intergranular fracture, and the fraction of cleavage fractures decreased gradually as secondary work embrittlement temperature rose.