Effect of 0 ~0. 072% La on inclusion

structure and elevated temperature tensile properties of 0. 20C stee

]

melted by a 10 kg medium frequency vacuum induction furnace has been studied by scanning electron microscope

energy dispersive X-ray spectrometer and Gleeble-1500 simulating test machine. Results showed that with rare earth metal La modified treated on inclusions in steel such as MnS and Al

2

O

3

the ellipsoidal and spherical RE inclusions RE

2

O

3

RE

2

O

2

S and RES with size ≤2 μm formed in steel

the hot ductility of 0. 20C steel at 850 〜1 050 °C obviously increased and the lath martensite structure in steel water-quenched after high temperature tensile test was finer than that non-adding La.