In the last three decades new stronger modified 9%Cr steels have been introduced in new power plants with steam parameters up to 300 bar(1 bar =10~5 Pa) and 600℃. In order to further increase the steam parameters of ...In the last three decades new stronger modified 9%Cr steels have been introduced in new power plants with steam parameters up to 300 bar(1 bar =10~5 Pa) and 600℃. In order to further increase the steam parameters of steel based power plants up to a target value of 650℃/ 325 bar it is necessary to double the creep strength compared with todays strongest 9%Cr steels,and at the same time the resistance against steam oxidation must be improved by adding 12%Cr to the steel. However,so far all attempts to make stronger 12%Cr steels have been unsuccessful because the high chromium content introduced severe microstructure instabilities in the tested steels.Recently,it was found that the microstructure instabilities in 11%- 12%Cr steels can be explained by the precipitation of coarse Cr(V,Nb)N Z-phases, which dissolve fine(V,Nb)N nitrides. A new possibility to use the Z-phase for strengthening of 12%Cr steels has been identified,and the development of stable strong martensitic 12%Cr steels based on this concept is expected to allow the construction of 325 bar/ 650℃steam power plants all based on steel.展开更多
Accurate position measurements are extremely valuable in the shipping industry for various reasons such as safety(collision avoidance),security(situational awareness),fuel-saving(weather identification),punctuality(ro...Accurate position measurements are extremely valuable in the shipping industry for various reasons such as safety(collision avoidance),security(situational awareness),fuel-saving(weather identification),punctuality(route prediction),etc.Although GNSS(Global Navigation Satellite System)receivers installed on-board the ships are proven to be highly accurate,the data logging process may occasionally be problematic,mainly due to the complexity of the measurements and the decimal precision that is required.Data were collected from 3 years of operations of 228 Maersk Line container vessels and an analysis reveals that there is a substantial amount (≈20%) of historical position measurements sent to shore that does not reflect reality.In the study,the sources of the faulty logged position measurements are categorized and an interpolation methodology is proposed to validate and correct them by using AIS(Automatic Identification System)data.展开更多
文摘In the last three decades new stronger modified 9%Cr steels have been introduced in new power plants with steam parameters up to 300 bar(1 bar =10~5 Pa) and 600℃. In order to further increase the steam parameters of steel based power plants up to a target value of 650℃/ 325 bar it is necessary to double the creep strength compared with todays strongest 9%Cr steels,and at the same time the resistance against steam oxidation must be improved by adding 12%Cr to the steel. However,so far all attempts to make stronger 12%Cr steels have been unsuccessful because the high chromium content introduced severe microstructure instabilities in the tested steels.Recently,it was found that the microstructure instabilities in 11%- 12%Cr steels can be explained by the precipitation of coarse Cr(V,Nb)N Z-phases, which dissolve fine(V,Nb)N nitrides. A new possibility to use the Z-phase for strengthening of 12%Cr steels has been identified,and the development of stable strong martensitic 12%Cr steels based on this concept is expected to allow the construction of 325 bar/ 650℃steam power plants all based on steel.
基金supported by“InnovationsFonden Danmark”with case number 8053-00231B and“Den Danske Maritime Fond”with case number 2018-060.
文摘Accurate position measurements are extremely valuable in the shipping industry for various reasons such as safety(collision avoidance),security(situational awareness),fuel-saving(weather identification),punctuality(route prediction),etc.Although GNSS(Global Navigation Satellite System)receivers installed on-board the ships are proven to be highly accurate,the data logging process may occasionally be problematic,mainly due to the complexity of the measurements and the decimal precision that is required.Data were collected from 3 years of operations of 228 Maersk Line container vessels and an analysis reveals that there is a substantial amount (≈20%) of historical position measurements sent to shore that does not reflect reality.In the study,the sources of the faulty logged position measurements are categorized and an interpolation methodology is proposed to validate and correct them by using AIS(Automatic Identification System)data.
