[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-665635-105":59,"doc-detail-665635-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","the-calculation-of-ttt-and-cct-diagrams-for-general-steels","The Calculation of TTT and CCT diagrams for General Steels","","Knowledge of TTT and CCT diagrams is critical for thermomechanical processing of steels, yet wide alloy ranges, sensitivity to composition, and dependence on grain size make comprehensive experimental diagram sets impractical. Prior models typically apply mainly to carbon and low alloy steels, limiting coverage for more highly alloyed compositions. This work develops and validates a model for accurate TTT and CCT diagrams for general steels, including medium to high alloy and tool steels, for integration in JMatPro.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/the-calculation-of-ttt-and-cct-diagrams-for-general-steels/665635/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/the-calculation-of-ttt-and-cct-diagrams-for-general-steels/665635.png","ImageObject",300,407,{"name":92,"@type":93},"\tJames","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-10-29",true,{"@type":102,"interactionType":103,"userInteractionCount":19},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"Why are TTT and CCT diagrams important in steel processing?","Question",{"text":112,"@type":113},"They guide thermomechanical processing by describing how phase transformations evolve with time and temperature during steel heat treatment.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"What limitation affects existing calculation models for TTT and CCT diagrams?",{"text":117,"@type":113},"Models are usually limited in applicability, often performing best for carbon and low alloy steels but struggling with more highly alloyed types.",{"name":119,"@type":110,"acceptedAnswer":120},"What is the goal of the present work and how is success validated?",{"text":121,"@type":113},"The work aims to create a model that calculates accurate TTT and CCT diagrams for general steels, including medium to high alloy and tool steels, and then validates it extensively against experiments before inclusion in JMatPro.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},665635,1793305347,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":19,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":139,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":129,"read_time":41},2336474466412,"https://ap-avatar.wpscdn.com/davatar_155a257f0dc6eb9ab79c44ca47cae57d","The Calculation ofTTT and CCT diagrams for General Steels  \nN. Saunders1, Z. Guo2, X. Li2, A.P. Miodownik1 and J.-P. Schillé2  \n1Thermotech Ltd., Surrey Technology Centre, The Surrey Research Park  \nGuildford GU2 7YG, U.K.  \n2 Sente Software Ltd., Surrey Technology Centre, The Surrey Research Park  \nGuildford GU2 7YG, U.K.  \nAbstract  \nKnowledge of the TTT or CCT diagrams of steels is an important factor in the thermomechanical processing of steels. Much experimental work has been undertaken to determine such diagrams. However, the combination of wide alloy specification ranges, coupled with sharp sensitivity to composition changes plus a dependency on grain size, means that it is impossible to produce enough diagrams for generalised use. To this end significant work has been undertaken over recent decades to develop models that can calculate TTT and CCT diagrams for steels. Almost without exception, these models have been shown to be limited in applicability to carbon and low alloy steels. The aim of the present work is to develop a model that can provide accurate TTT and CCT diagrams for general steels, including medium to high alloy types, tool steels, 13%Cr steels etc., for inclusion in the software programme JMatPro. This aim has been achieved and the present paper provides a background to the calculation method and present results of an extensive validation of the model against experiment.  \nIntroduction  \nAs part of the development of the software programme JMatPro, phase transformation models have been included for a variety of alloy types [1,2,3,4] e.g. Al-alloys, Ni-based superalloys, Ti-alloys and for TCP phases such as σ and χ in stainless steels. JMatPro also incorporated a capability to calculate transformations involving ferrite, pearlite and bainite in HSLA steels closely based on the model of Kirkaldy [2] . To bring this calculation capability in-line with JMatPro's capability for other alloys, where high alloy contents can be routinely handled, work has been undertaken to extend this model capability to steels of high alloy content.  \nThere is a hugely extensive published literature concerned with the transformations in steels but, of this, only a small part is given over to the calculation ofTTT and CCT diagrams. The pioneering work of Kirkaldy and co-workers [5,6] showed that it was possible to calculate quite accurate TTT and CCT diagrams as well as the Jominy hardenability for low alloy steels. Later work by Bhadeshia [7,8] used a different methodology to determine start curves for ferrite and bainite transformations and tested the model against experiment. The model of Bhadeshia has been extended by Lee [9, 10] to cover slightly higher concentrations. However, although successful for low alloy steels these models are limited when it comes to more highly alloyed types.  \nOne of the drawbacks of both models has been the use of dilute solution thermodynamics in calculating transformation temperatures. This can now be overcome using thermodynamic models [11] that provide high quality results for steels in general, ranging from stainless steels, to tool steels as well as the low to medium alloy range types.  \nThe aim of the present work is to combine the more extensive thermodynamic models with a kinetic model to see if the composition range of applicability could be extended to cover a wider range of steels, including the highly alloyed types. The model of Kirkaldy was chosen as the basis for the new calculations as there is a clearly identifiable set of input parameters that are required and which can be readily calculated. It is also has empirical parameters that can be adjusted easily and controllably.  \nTransformation model  \nThe model of Kirkaldy and co-workers  \nA model for the calculation of ferrite and pearlite was first presented by Kirkaldy et al. [5], following equations developed by Zener and Hillert [12, 13] . In the initial model no attempt was made to differentiate between the diffusive and di","cbCaifuS1qu88rqX","https://ap.wps.com/l/cbCaifuS1qu88rqX","pdf",161984,12,"English","# Abstract\n# Introduction\n# Transformation model\n## The model of Kirkaldy and co-workers","[{\"question\":\"Why are TTT and CCT diagrams important in steel processing?\",\"answer\":\"They guide thermomechanical processing by describing how phase transformations evolve with time and temperature during steel heat treatment.\"},{\"question\":\"What limitation affects existing calculation models for TTT and CCT diagrams?\",\"answer\":\"Models are usually limited in applicability, often performing best for carbon and low alloy steels but struggling with more highly alloyed types.\"},{\"question\":\"What is the goal of the present work and how is success validated?\",\"answer\":\"The work aims to create a model that calculates accurate TTT and CCT diagrams for general steels, including medium to high alloy and tool steels, and then validates it extensively against experiments before inclusion in JMatPro.\"}]","The Calculation of TTT and CCT diagrams for General Steels | PDF"]