Study on the materials of coal liquefaction pilot plant (The 2nd report) - coal liquefaction reactors

摘要

The results of the material inspections of equipment (except for coal liquefaction reactors) and pipes of liquefaction unit in 150t/d Bituminous coal liquefaction pilot plant (PP) were reported in the previous paper. The liquefaction reactors have been operated under the severe conditions such as high temperature (450-460℃), high pressure (17.0-19.0 MPa) and hydrogen service. It is necessary to be lower sensitivity for brittle fracture and toughness degradation. The materials having resistance properties for methane bubble and intergranular cracking etc. and having a good weldability are required for this liquefaction reactors. The further materials compared with the 2-1/4Cr-1Mo steel being widely used in the petrochemical plants are required for the liquefaction reactors. 3Cr-1Mo-1/4V-Ti-B steel was developed for that reason and used in the liquefaction reactors and high temp. separator. It was confirmed that this new developed steel is useful, for the damage caused by hydrogen and metallurgical degradation (brittle fracture, decrease in the strengh etc. ), as a result of the material inspections. TP347 over lay was also useful for corrosion and stress corrosion cracking.