Effect of Cerium on the Microstructure and Inclusion Evolution of C-Mn Cryogenic Vessel Steels

The effects of Cerium (Ce) were studied on the casting slab quality, microstructure, and inclusion evolution of cryogenic vessel steel. An optical metallographic microscope, scanning electron microscope, energy dispersive spectrometer, and Thermo-calc thermodynamic software were used for characterization and analysis. The results indicated that the central segregation was significantly improved after adding Ce and reached the lowest level when the content of Ce was 0.0009 wt.%. Meanwhile, the presence of Ce reduces the size of ferrite and improves pearlite morphology. Ce also enables the modification of Al2O3 and MnS + Ti4C2S2 inclusions into ellipsoid CeAlO3 and spherical Ce2O2S + Ti4C2S2 composite inclusions, respectively, which are easier to remove. The formed Ce2O2S inclusions are fine and can work as heterogeneous nucleation points to refine the microstructure of steel.

Research on Cryogenic Property Inspection Technology of Cryogenic Vessels with Valve

According to the current development situation of valve used in domestic cryogenic vessel and the level of product quality, through comparison and analysis similarities and differences of cryogenic vessels with the technical standards in cryogenic property inspection technology at home and abroad, then put forward to the basic requirements and key technical indicators for cryogenic property test aspects of cryogenic vessels with valve, provide suggestions for the establishment of national standard for cryogenic vessels with valves in China.