{"title":"Cavitation during creep-fatigue loading","authors":"R. Sandström","doi":"10.1080/09603409.2023.2188356","DOIUrl":"https://doi.org/10.1080/09603409.2023.2188356","url":null,"abstract":"ABSTRACT Cavitation is expected to be of equal importance for assessing creep damage during cyclic as during static loading conditions. However, the amount of cavitation data is much more limited in the former case. In particular, two features have been missing: basic models for hysteresis loops and for the formation of cavities during cyclic loading. In this paper, such models are presented and compared with published data for LCF of 1Cr0.5Mo steel. To study the role of the creep–fatigue interaction, the influence of pre-creep as well as LCF cycles with and without hold times were included. Hysteresis loops under these conditions could be well reproduced. A model for nucleation of cavities during creep is adapted to cyclic loading. The total creep strain determined with the help of the loop model could be used to predict the number of cavities during the different LCF loops in an acceptable way.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77855879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Introduction to MIMA-2 conference special issue","authors":"S. Holdsworth","doi":"10.1080/09603409.2023.2188679","DOIUrl":"https://doi.org/10.1080/09603409.2023.2188679","url":null,"abstract":"In addition, four additional presentations were made in a final Plenary Session (Session 6). Following a Rapporteur overview summary of the MIMA-2 conference proceedings, the MHT MIMA-2 Special Issue contains 7 papers based on presentations made during the course of this conference. Importantly, papers originating from four of the main sessions are included [an eighth paper based on a third session presentation was published in Materials at High Temperatures, 2023, 40(1), 88-98]. For example, the first session, which was concerned with High Temperature Materials Issues, mainly (but not exclusively) covered developments associated with 9Cr-3W3Co-VNbBN (alternatively referred to as MARBN). The MARBN steel was originally developed in Japan by a group headed by Fujio Abe, who has continued to be active in studying the metallurgy of this alloy, and a number of other associated advanced martensitic steels. It was therefore appropriate that the first presentation in the first session of the conference was by Dr Abe, and that the 9Cr-3W-3CoVNbBN alloy played an integral part in the first paper in this Special Issue. In fact, Dr Abe’s paper is more generally concerned with The role of inclusions on the degradation in creep life and rupture ductility of ferritic power plant steels and, more specifically, considers the role of BN, AlN and MnS particles on degradation of the creep properties of 9 to 12%Cr martensitic steels and a 1%Cr bainitic steel at temperatures in the range 550 to 700°C. A second paper from the first session concerns Experience of P93 manifold welding under fabrication conditions, and was by de-Smet, Tang & Bok (of Siemens Energy Heat Transfer Technology). While MARBN is an ASME Code Case variant of P93 (or 9Cr-3W-3Co), the presented evidence indicates that further optimisation of the heat treatment and welding procedures are required in order to attain the required impact toughness properties for weldments of the more generic grade of this steel. The second session was concerned with Plant Life Assessment, with the contribution of Professor Nonaka (of Tohoku University) from the Plenary Session representing the Japanese perspective on this topic. Entitled Activities to advance residual life evaluation techniques for highly aged power plant, Professor Nonaka’s paper concerns the wide ranging activities of a Japanese Materials Sciences Society Working Group and recent developments in techniques being adopted for the life assessment of very old power generation units. Two papers based on presentations from the third session (Plant Inspection and Maintenance) are included. The first by Pascal Decoussemaeker (of GE Power, Switzerland) is concerned with Risk-based life management for steam turbines and generators, and considers the necessary important details of an asset management program to ensure reliable operation over the commercial life of, in particular, steam power plant. The third session presentation of Adam Wojcik (Matelect, UK) et","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85697038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dj Allen, K. Asvergren, S. Holdsworth, S. Huysmans, S. Lockyer, D. Robertson, A. Shibli, R. Skelton, A. Tonti, R. Vanstone, K. Yagi
{"title":"Rapporteur overview summary of the 2nd on-line MIMA international conference concerning high temperature plant: materials, inspection, monitoring & assessment","authors":"Dj Allen, K. Asvergren, S. Holdsworth, S. Huysmans, S. Lockyer, D. Robertson, A. Shibli, R. Skelton, A. Tonti, R. Vanstone, K. Yagi","doi":"10.1080/09603409.2023.2188681","DOIUrl":"https://doi.org/10.1080/09603409.2023.2188681","url":null,"abstract":"Anodamine-based","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75970776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Dawson, F. Duarte-Martinez, S. Gray, J. Nicholls, G. Gibson, J. Leggett, G. Tatlock
{"title":"Environmentally assisted cracking of a single crystal nickel-based superalloy","authors":"K. Dawson, F. Duarte-Martinez, S. Gray, J. Nicholls, G. Gibson, J. Leggett, G. Tatlock","doi":"10.1080/09603409.2023.2182587","DOIUrl":"https://doi.org/10.1080/09603409.2023.2182587","url":null,"abstract":"ABSTRACT Single crystal material, of CMSX-4® alloy composition, was cast and secondary orientation was controlled at the machining stage, to produce c-ring cross-section tubes with known crystallographic orientations. The c-ring tubes were coated with NaCl before being subject to loading up to 700MPa and heated for durations of up to 2 hrs at 550°C in flowing environments containing air and SO2. No cracking was observed in short term tests that were run in the absence of either NaCl, or SO2, indicating a symbiotic interaction is required to initiate cracking. Experiments confirm the presence of oxygen, chlorine and sulphur at the crack tips, formed along {001} crystallographic planes, however, they were distributed discretely, with several oxide and sulphide phases observed. In this work, we image, analyse and identify the phases formed during the cracking and corrosion of CMSX-4® superalloy and hypothesise on the complex chemical interactions that take place during crack initiation.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74450159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Oxidation of SS304 and SS316 and the formation of diffusionally isolated regions leading to localised premature breakaway oxidation","authors":"M. Taylor, J. Husband","doi":"10.1080/09603409.2023.2177938","DOIUrl":"https://doi.org/10.1080/09603409.2023.2177938","url":null,"abstract":"ABSTRACT The results are presented on the oxidation behaviour of two chromia-forming steels, over the temperature range 800°C to 900°C, regions of premature localised breakaway oxidation were observed. SiO2 formation along emergent grain boundaries encapsulated smaller grains, acting as diffusion barriers to the replenishment of chromium from deeper in the alloy. Rapid depletion of chromium from these isolated grains continued with increasing time until the concentration was insufficient to maintain a protective Cr2O3 resulting in the localised chemical failure and formation of breakaway oxides. A finite difference model was used to demonstrate the effect of SiO2 formation. It was also found that the low concentration of silicon restricted the encapsulation process to only the smaller grains at the surface and protective oxidation was re-established underneath at the alloy surface. The predicted lifetime of components with wall thicknesses of 2 mm was calculated to be in excess of 30 years.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77567436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adam Wojcik, Matthew Waitt, Alberto S. Santos, A. Shibli
{"title":"A review of factors affecting the use of Electrical Potential Drop (EPD) for creep life monitoring","authors":"Adam Wojcik, Matthew Waitt, Alberto S. Santos, A. Shibli","doi":"10.1080/09603409.2023.2175563","DOIUrl":"https://doi.org/10.1080/09603409.2023.2175563","url":null,"abstract":"ABSTRACT To help determine remaining lifetime of pressure vessels suffering creep, the authors have previously developed a method and presented promising results using a combination of AC and DC electrical potential drop (EPD) on-line monitoring, detecting both final cracking as well as incipient creep damage. The latter was tentatively ascribed to the development of cavitation damage, but recent modelling and separate off-line measurements have shown that cavitation is unlikely to provide enough of a change in electrical properties to explain all of the variations previously observed. Here we gather the results obtained to date, and review their likely relationships in an attempt to obtain a greater insight into the mechanisms at play. Whilst changes in both on-line and off-line EPD are largely in accord, the belief now is that the changes seen cannot be fully explained by cavitation development and that EPD is responding to other creep induced phenomena as well.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80234102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Activities to advance residual life evaluation techniques for highly aged power boiler materials","authors":"I. Nonaka","doi":"10.1080/09603409.2023.2181569","DOIUrl":"https://doi.org/10.1080/09603409.2023.2181569","url":null,"abstract":"ABSTRACT In Japan, national guidelines of residual life evaluation for aged thermal power equipment were formulated in 1999. Several issues had recently come to light with the increase in ageing systems, including the emergence of unexpected mode of creep damage, the verification of practical applicability of the damage calibration curve generated in the laboratory, how to deal with creep-fatigue damage due to increased numbers of plant starts and stops, occurrence of plastic deformation in the accelerated creep test and the need for the creep damage monitoring method during plant operation. The Working Group to Advance Residual Life Evaluation Techniques was established in 2011 within the Society of Materials Science, Japan, to identify issues and discuss improvement measures. This paper provides an overview of the results of the working group activities.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78933867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Risk-based asset life management for steam turbines and generators","authors":"P. Decoussemaeker, S. Vittal, Shayan I Ahmed","doi":"10.1080/09603409.2023.2175154","DOIUrl":"https://doi.org/10.1080/09603409.2023.2175154","url":null,"abstract":"ABSTRACT To ensure a good return on investment, it is important for power plant operators to set up an asset management program that will ensure reliable operation over the commercial life of the plant. General Electric (GE) has been applying a variety of asset management technologies to improve power plant life and performance for our customers. These methods consider various inputs including equipment design knowledge; asset condition assessed from real-time monitoring and inspection data; and lessons learned from repairing, operating and maintaining thousands of assets globally. In this paper, a subset of that information is applied to develop a methodology to perform risk-based health and life assessments for steam turbines and generators. The method has been used on several steam power plants around the world, to help operators of ageing steam plants make the right decisions related to end-of-life management or life extension.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84894104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Role of inclusions on degradation in creep life and rupture ductility of ferritic power plant steels","authors":"F. Abe","doi":"10.1080/09603409.2023.2175562","DOIUrl":"https://doi.org/10.1080/09603409.2023.2175562","url":null,"abstract":"ABSTRACT The role of BN, AlN and MnS particles on the degradation in creep life and rupture ductility has been investigated for 9 to 12Cr martensitic steels and 1Cr bainitic steel mainly at 550 to 650 oC. The BN particles form in Gr.92 and Gr.122 during normalising at around 1100 oC. The BN particles have nothing to do with the degradation in creep life. The AlN particles precipitate in the high-Al heats of 12Cr-1Mo-1 W-0.3 V steel during creep, reducing dissolved nitrogen and fine nitrides beneficial for the creep strength and degrading the creep life. The MnS particles have nothing to do with the degradation in creep life of 1Cr-1Mo-0.25 V steel. The BN, AlN and MnS particles are responsible for the degradation in reduction of area of the steels by accelerating the formation of creep voids at interfaces between the particles and alloy matrix.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72528482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of Cr on the oxidation behaviour of polycrystalline nickel based superalloys","authors":"Caixia Xia, Xiangyu Liu, Zaiwang Huang","doi":"10.1080/09603409.2023.2177939","DOIUrl":"https://doi.org/10.1080/09603409.2023.2177939","url":null,"abstract":"ABSTRACT Isothermal oxidation behaviour of two nickel base superalloys with different Cr contents was investigated in the temperature range of 700–800 °C. Weight–change curves show that weight loss increases with increasing temperature and a relatively lower Cr ratio corresponds to slow weight gain rate. Microscopic observations uncover that oxidation penetration attacks the alloys primarily along grain boundary especially for the lower-Cr alloy, and the penetration depth is strongly dependent on the oxidation temperature. The underlying oxidation mechanisms of the two alloys are explained using energy-dispersive x-ray spectroscopy and X-ray photoelectron spectroscopy.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76831103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}