Metallurgical Analysis of a Plain Carbon-Steel Plate after Long-Term Service in a Coal Gasifier.

摘要

A steel inner liner which was directly exposed to a coal gasification reaction for 20years was examined. The microstructure was observed,the mechanical properties measured,and the chemical composition analyzed as functions of position in the vessel. Evidence of corrosion,embrittlement,and carburization was sought. Microstructural variations were rationalized and a correlation of microstructure and mechanical properties was attempted. The initial properties of the steel were estimated and compared to the final measured properties. Certain conclusions were reached concerning the operating conditions of the vessel and the suitability of the material for its design environment. Two materials samples from another high-pressure gasifier were obtained in 1974when the inner lined failed while in service. Details are presented in the Appendix to this report.