{"title":"Tracking research on the performance changes of S31042 steel under long term service","authors":"","doi":"10.1016/j.ijpvp.2024.105344","DOIUrl":null,"url":null,"abstract":"<div><div>S31042 is widely used in ultra-supercritical units due to its excellent comprehensive performance at high temperatures. Tracking and monitoring research was conducted on as-received S31042 tubes and tubes in service for 13 k hours, 31 k hours, and 52 k hours at 650 °C. The results show that as the service time increased, a large quantity of M<sub>23</sub>C<sub>6</sub> phase precipitated along the grain boundaries, gathered and grew up into the bulk. This weakened of the grain boundaries, which facilitated crack propagation and significantly reduced the plasticity and toughness of the S31042 heat-resistant steel. After 13 k hours of operation, the dispersion strengthening of the precipitated phase inside the grain and grain boundary led to a substantial increase in hardness, while there was no obvious change in strength. However, after 52 k hours of operation, the dispersed precipitated phase within the grain slowly aggregated and grew, decreasing the effectiveness of dispersion strengthening. Consequently, both the high-temperature strength and hardness of the S31042 steel gradually decreased. As the service time increased, the continuously distributed and similarly sized M<sub>23</sub>C<sub>6</sub> phases on the grain boundaries of S31042 developed into an inhomogeneous coarsening chain structure. Additionally, the appearance of nanoscale secondary NbCrN and M<sub>23</sub>C<sub>6</sub> phases within the grain and their resulting precipitation strengthening effects were the main reasons for the significant change in S31042 hardness values. Based on these findings, the residual life of S31042 heat-resistant steel in service was predicted using an extrapolation method based on high-temperature creep rupture tests and the relationship model between hardness and the P function. A comparison of the L-M parametric life prediction results with the strength extrapolation life prediction results based on the standard creep rupture test shows that the creep rupture strength extrapolation method is slightly conservative. Therefore, the prediction results based on the hardness L-M parameter method, which is simple and easy to perform, can be used for preliminary life prediction.</div></div>","PeriodicalId":54946,"journal":{"name":"International Journal of Pressure Vessels and Piping","volume":null,"pages":null},"PeriodicalIF":3.0000,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Pressure Vessels and Piping","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0308016124002217","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
S31042 is widely used in ultra-supercritical units due to its excellent comprehensive performance at high temperatures. Tracking and monitoring research was conducted on as-received S31042 tubes and tubes in service for 13 k hours, 31 k hours, and 52 k hours at 650 °C. The results show that as the service time increased, a large quantity of M23C6 phase precipitated along the grain boundaries, gathered and grew up into the bulk. This weakened of the grain boundaries, which facilitated crack propagation and significantly reduced the plasticity and toughness of the S31042 heat-resistant steel. After 13 k hours of operation, the dispersion strengthening of the precipitated phase inside the grain and grain boundary led to a substantial increase in hardness, while there was no obvious change in strength. However, after 52 k hours of operation, the dispersed precipitated phase within the grain slowly aggregated and grew, decreasing the effectiveness of dispersion strengthening. Consequently, both the high-temperature strength and hardness of the S31042 steel gradually decreased. As the service time increased, the continuously distributed and similarly sized M23C6 phases on the grain boundaries of S31042 developed into an inhomogeneous coarsening chain structure. Additionally, the appearance of nanoscale secondary NbCrN and M23C6 phases within the grain and their resulting precipitation strengthening effects were the main reasons for the significant change in S31042 hardness values. Based on these findings, the residual life of S31042 heat-resistant steel in service was predicted using an extrapolation method based on high-temperature creep rupture tests and the relationship model between hardness and the P function. A comparison of the L-M parametric life prediction results with the strength extrapolation life prediction results based on the standard creep rupture test shows that the creep rupture strength extrapolation method is slightly conservative. Therefore, the prediction results based on the hardness L-M parameter method, which is simple and easy to perform, can be used for preliminary life prediction.
期刊介绍:
Pressure vessel engineering technology is of importance in many branches of industry. This journal publishes the latest research results and related information on all its associated aspects, with particular emphasis on the structural integrity assessment, maintenance and life extension of pressurised process engineering plants.
The anticipated coverage of the International Journal of Pressure Vessels and Piping ranges from simple mass-produced pressure vessels to large custom-built vessels and tanks. Pressure vessels technology is a developing field, and contributions on the following topics will therefore be welcome:
• Pressure vessel engineering
• Structural integrity assessment
• Design methods
• Codes and standards
• Fabrication and welding
• Materials properties requirements
• Inspection and quality management
• Maintenance and life extension
• Ageing and environmental effects
• Life management
Of particular importance are papers covering aspects of significant practical application which could lead to major improvements in economy, reliability and useful life. While most accepted papers represent the results of original applied research, critical reviews of topical interest by world-leading experts will also appear from time to time.
International Journal of Pressure Vessels and Piping is indispensable reading for engineering professionals involved in the energy, petrochemicals, process plant, transport, aerospace and related industries; for manufacturers of pressure vessels and ancillary equipment; and for academics pursuing research in these areas.