{"id":8457,"date":"2019-01-10T21:03:49","date_gmt":"2019-01-10T21:03:49","guid":{"rendered":"https:\/\/staging.asminternational.org\/hts-new\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/"},"modified":"2023-02-07T04:48:52","modified_gmt":"2023-02-07T04:48:52","slug":"one-minute-mentor-processing-sequence-for-austempered-ductile-iron","status":"publish","type":"post","link":"https:\/\/www.asminternational.org\/hts\/one-minute-mentor-processing-sequence-for-austempered-ductile-iron\/","title":{"rendered":"One-Minute Mentor: Processing sequence for austempered ductile iron"},"content":{"rendered":"<p style=\"margin-bottom:.0001pt\"><span style=\"line-height:normal\"><span style=\"font-size:12.0pt\">The figure <span style=\"background:white\"><span style=\"color:black\">shows an isothermal transformation (IT) diagram for a ductile cast iron, together with a processing sequence depicting the production of ADI. In this process, austenitizing is followed by rapid quenching (usually in molten salt) to an intermediate temperature range for a time that allows the unique metastable carbon-rich (~2% C) austenitic matrix (?<sub>H<\/sub>) to evolve simultaneously with nucleation and growth of a platelike ferrite (?) or of ferrite plus carbide, depending on the austempering temperature and time at temperature. <\/span><\/span><\/span><\/span><\/p>\n<p style=\"margin-bottom:.0001pt\">&nbsp;<\/p>\n<p style=\"margin-bottom:.0001pt\"><span style=\"line-height:normal\"><span style=\"font-size:12.0pt\"><span style=\"background:white\"><span style=\"color:black\">This austempering reaction progresses to a point at which the entire matrix has been transformed to the metastable product (stage I in the figure). Then that product is \u201cfrozen in\u201d by cooling to room temperature <i>before<\/i> the true bainitic ferrite plus carbide phases can appear (stage II).<\/span><\/span><\/span><\/span><\/p>\n<p style=\"margin-bottom:.0001pt\">&nbsp;<\/p>\n<p style=\"margin-bottom:.0001pt\"><span style=\"line-height:normal\"><span style=\"font-size:12.0pt\"><span style=\"background:white\"><span style=\"color:black\">&nbsp;In ductile cast irons the presence of 2 to 3 wt% Si prevents the rapid formation of iron carbide (Fe<sub>3<\/sub>C). Hence the carbon rejected during ferrite formation in the first stage of the reaction (stage I) enters the matrix austenite, enriching it and stabilizing it thermally to prevent martensite formation upon subsequent cooling. <\/span><\/span><\/span><\/span><\/p>\n<p style=\"margin-bottom:.0001pt\">&nbsp;<\/p>\n<p style=\"margin-bottom:.0001pt\"><span style=\"line-height:normal\"><span style=\"font-size:12.0pt\"><span style=\"background:white\"><span style=\"color:black\">Thus the processing sequence shows that the austempering reaction is terminated before stage II begins, and illustrates the decrease in the martensite start (M<sub>s<\/sub>) and martensite finish (M<sub>f<\/sub>) temperatures as ?<sub>H<\/sub> forms in stage I. The kinetics of stages I and II have been described in detail in the literature. <\/span><\/span><\/span><\/span><\/p>\n<p style=\"margin-bottom:.0001pt\">&nbsp;<\/p>\n<p style=\"margin-bottom:.0001pt\"><span style=\"line-height:normal\"><span style=\"font-size:12.0pt\"><span style=\"background:white\"><span style=\"color:black\">Typical austempering times range from 1 to 4 hours. If the part is austempered too long, undesirable bainite will form. Unlike steel, bainite in cast iron microstructures exhibits lower toughness and ductility.<\/span><\/span><\/span><\/span><\/p>\n<p style=\"margin-bottom:.0001pt\">&nbsp;<\/p>\n<p><span style=\"font-family:&quot;Helvetica&quot;,sans-serif\"><span style=\"color:#0f5db9\"><a href=\"https:\/\/matdata-s.asminternational.org\/hbk\/do\/section\/content\/V04D\/D00\/A01\/index.htm\" target=\"page\" title=\"Volume 4D, Heat Treating of Irons and Steels\" rel=\"noopener\"><span style=\"color:#0f5db9\"><span style=\"text-decoration:none\"><span style=\"text-underline:none\">Volume 4D, Heat Treating of Irons and Steels<\/span><\/span><\/span><\/a><\/span><\/span><span style=\"font-family:&quot;Helvetica&quot;,sans-serif\"><span style=\"color:#323232\"> -&gt;<\/span><\/span><span style=\"font-family:&quot;Helvetica&quot;,sans-serif\"><span style=\"color:#0f5db9\"><a href=\"https:\/\/matdata-s.asminternational.org\/hbk\/do\/section\/content\/V04D\/D00\/A01\/index.htm\" target=\"page\" title=\"Volume 4D, Heat Treating of Irons and Steels\" rel=\"noopener\"><span style=\"color:#0f5db9\"><span style=\"text-decoration:none\"><span style=\"text-underline:none\"> Heat Treatiment of Cast Irons -&gt; <\/span><\/span><\/span><\/a><\/span><\/span><span style=\"font-family:&quot;Helvetica&quot;,sans-serif\"><span style=\"color:#323232\">-&gt; <\/span><\/span><span style=\"font-family:&quot;Helvetica&quot;,sans-serif\"><span style=\"color:#0f5db9\"><a href=\"https:\/\/matdata-s.asminternational.org\/hbk\/do\/section\/content\/V04D\/D05\/A03\/index.htm\" target=\"page\" title=\"Heat Treating and Properties of Ductile Iron\" rel=\"noopener\"><span style=\"color:#0f5db9\"><span style=\"text-decoration:none\"><span style=\"text-underline:none\">Heat Treating and Properties of Ductile Iron<\/span><\/span><\/span><\/a><\/span><\/span><span style=\"font-family:&quot;Helvetica&quot;,sans-serif\"><span style=\"color:#323232\"> -&gt; General Characteristics<\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The figure shows an isothermal transformation (IT) diagram for a ductile cast iron, together with a processing sequence depicting the production of ADI.<\/p>\n","protected":false},"author":63082,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[440,441,1],"tags":[],"class_list":["post-8457","post","type-post","status-publish","format-standard","hentry","category-news","category-news-articles","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>One-Minute Mentor: Processing sequence for austempered ductile iron - Heat Treating Society<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"One-Minute Mentor: Processing sequence for austempered ductile iron - Heat Treating Society\" \/>\n<meta property=\"og:description\" content=\"The figure shows an isothermal transformation (IT) diagram for a ductile cast iron, together with a processing sequence depicting the production of ADI.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/\" \/>\n<meta property=\"og:site_name\" content=\"Heat Treating Society\" \/>\n<meta property=\"article:published_time\" content=\"2019-01-10T21:03:49+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-02-07T04:48:52+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/results\\\/-\\\/journal_content\\\/56\\\/10192\\\/36238856\\\/NEWS\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/results\\\/-\\\/journal_content\\\/56\\\/10192\\\/36238856\\\/NEWS\\\/\"},\"author\":{\"name\":\"\",\"@id\":\"\"},\"headline\":\"One-Minute Mentor: Processing sequence for austempered ductile iron\",\"datePublished\":\"2019-01-10T21:03:49+00:00\",\"dateModified\":\"2023-02-07T04:48:52+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/results\\\/-\\\/journal_content\\\/56\\\/10192\\\/36238856\\\/NEWS\\\/\"},\"wordCount\":302,\"publisher\":{\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/#organization\"},\"articleSection\":[\"news\",\"News Articles\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/results\\\/-\\\/journal_content\\\/56\\\/10192\\\/36238856\\\/NEWS\\\/\",\"url\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/results\\\/-\\\/journal_content\\\/56\\\/10192\\\/36238856\\\/NEWS\\\/\",\"name\":\"One-Minute Mentor: Processing sequence for austempered ductile iron - Heat Treating Society\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/#website\"},\"datePublished\":\"2019-01-10T21:03:49+00:00\",\"dateModified\":\"2023-02-07T04:48:52+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/results\\\/-\\\/journal_content\\\/56\\\/10192\\\/36238856\\\/NEWS\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/results\\\/-\\\/journal_content\\\/56\\\/10192\\\/36238856\\\/NEWS\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/results\\\/-\\\/journal_content\\\/56\\\/10192\\\/36238856\\\/NEWS\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"One-Minute Mentor: Processing sequence for austempered ductile iron\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/#website\",\"url\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/\",\"name\":\"Heat Treating Society\",\"description\":\"Heat Treating Society ASM International\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/#organization\",\"name\":\"Heat Treating Society\",\"url\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/cdn-prd-main.asm-media.cloud\\\/uploads\\\/sites\\\/85\\\/2022\\\/06\\\/layout_set_logo.png\",\"contentUrl\":\"https:\\\/\\\/cdn-prd-main.asm-media.cloud\\\/uploads\\\/sites\\\/85\\\/2022\\\/06\\\/layout_set_logo.png\",\"width\":286,\"height\":95,\"caption\":\"Heat Treating Society\"},\"image\":{\"@id\":\"https:\\\/\\\/www.asminternational.org\\\/hts\\\/#\\\/schema\\\/logo\\\/image\\\/\"}},{\"@type\":\"Person\",\"@id\":\"\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"One-Minute Mentor: Processing sequence for austempered ductile iron - Heat Treating Society","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/","og_locale":"en_US","og_type":"article","og_title":"One-Minute Mentor: Processing sequence for austempered ductile iron - Heat Treating Society","og_description":"The figure shows an isothermal transformation (IT) diagram for a ductile cast iron, together with a processing sequence depicting the production of ADI.","og_url":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/","og_site_name":"Heat Treating Society","article_published_time":"2019-01-10T21:03:49+00:00","article_modified_time":"2023-02-07T04:48:52+00:00","twitter_card":"summary_large_image","twitter_misc":{"Written by":"","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/#article","isPartOf":{"@id":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/"},"author":{"name":"","@id":""},"headline":"One-Minute Mentor: Processing sequence for austempered ductile iron","datePublished":"2019-01-10T21:03:49+00:00","dateModified":"2023-02-07T04:48:52+00:00","mainEntityOfPage":{"@id":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/"},"wordCount":302,"publisher":{"@id":"https:\/\/www.asminternational.org\/hts\/#organization"},"articleSection":["news","News Articles"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/","url":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/","name":"One-Minute Mentor: Processing sequence for austempered ductile iron - Heat Treating Society","isPartOf":{"@id":"https:\/\/www.asminternational.org\/hts\/#website"},"datePublished":"2019-01-10T21:03:49+00:00","dateModified":"2023-02-07T04:48:52+00:00","breadcrumb":{"@id":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.asminternational.org\/hts\/results\/-\/journal_content\/56\/10192\/36238856\/NEWS\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.asminternational.org\/hts\/"},{"@type":"ListItem","position":2,"name":"One-Minute Mentor: Processing sequence for austempered ductile iron"}]},{"@type":"WebSite","@id":"https:\/\/www.asminternational.org\/hts\/#website","url":"https:\/\/www.asminternational.org\/hts\/","name":"Heat Treating Society","description":"Heat Treating Society ASM International","publisher":{"@id":"https:\/\/www.asminternational.org\/hts\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.asminternational.org\/hts\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.asminternational.org\/hts\/#organization","name":"Heat Treating Society","url":"https:\/\/www.asminternational.org\/hts\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.asminternational.org\/hts\/#\/schema\/logo\/image\/","url":"https:\/\/cdn-prd-main.asm-media.cloud\/uploads\/sites\/85\/2022\/06\/layout_set_logo.png","contentUrl":"https:\/\/cdn-prd-main.asm-media.cloud\/uploads\/sites\/85\/2022\/06\/layout_set_logo.png","width":286,"height":95,"caption":"Heat Treating Society"},"image":{"@id":"https:\/\/www.asminternational.org\/hts\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":""}]}},"acf":[],"_links":{"self":[{"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/posts\/8457","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/users\/63082"}],"replies":[{"embeddable":true,"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/comments?post=8457"}],"version-history":[{"count":0,"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/posts\/8457\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/media?parent=8457"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/categories?post=8457"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.asminternational.org\/hts\/wp-json\/wp\/v2\/tags?post=8457"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}