{"id":4997,"date":"2025-06-23T10:33:58","date_gmt":"2025-06-23T05:03:58","guid":{"rendered":"https:\/\/study.madeeasy.in\/?p=4997"},"modified":"2025-07-19T11:40:37","modified_gmt":"2025-07-19T06:10:37","slug":"flame-hardening","status":"publish","type":"post","link":"https:\/\/www.madeeasy.in\/study\/me\/engineering-materials\/flame-hardening","title":{"rendered":"Flame Hardening"},"content":{"rendered":"<h2>Flame Hardening<\/h2>\n<ul>\n<li style=\"text-align: justify;\">The process consists of heating the surface of medium carbon steel by high temperature gas flame at 2400\u00b0C &#8211; 3300\u00b0C and immediately cooling in air or water. Heat may be supplied by oxyacetylene torch. The fuel caused by the flame may be oxyacetylene, natural gas or kerosene. The flame rapidly imparts large amounts of heat to the surface. The heat supply so quickly to the surface and for a short time, the core remains unaffected.<\/li>\n<li style=\"text-align: justify;\">As soon as the desire temperature is achieved water immediately sprayed which cools the surface.<\/li>\n<li style=\"text-align: justify;\">By proper control and cooling temperature. The core is not affected by treatment.<\/li>\n<li style=\"text-align: justify;\">The thickness of hardened layer is 2 &#8211; 4 mm and its surface structure is martensite.<\/li>\n<\/ul>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_79_1 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.madeeasy.in\/study\/me\/engineering-materials\/flame-hardening\/#Advantages\" >Advantages :<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.madeeasy.in\/study\/me\/engineering-materials\/flame-hardening\/#Disadvantages\" >Disadvantages :<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.madeeasy.in\/study\/me\/engineering-materials\/flame-hardening\/#Uses\" >Uses<\/a><\/li><\/ul><\/nav><\/div>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Advantages\"><\/span><strong> Advantages :<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li>There is practically no distortion of the work piece because only small sections of the work piece are heated.<\/li>\n<li>As heating rate is high the work surface remains clean.<\/li>\n<li>The process rate can be automated<\/li>\n<li>The process is more efficient for large work as compared to induction heating . It is very economical for large work.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Disadvantages\"><\/span><strong>Disadvantages :<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul style=\"text-align: justify;\">\n<li>Very thin section may get distorted extensively.<\/li>\n<li>Over heating may cause crack.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Uses\"><\/span><strong>Uses<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li style=\"text-align: justify;\">It is used to increase wear resistance and surface hardness Eg: piston pins, large gears, hand tools, shaft, mill rolls etc.<\/li>\n<li style=\"text-align: justify;\">As it can be seen from the TTT diagram of high carbon steel that martensite finish line appears approximately at 25\u00b0C. Hardenability of hypo and hyper enteroid steel is lower than eutectoid steel. So upon quenching the material into bath maintained at room temperature, martensite, pro-eutectic, cementite and retained eutectic will be present in the sample.<\/li>\n<li style=\"text-align: justify;\">To convert the sample into 100% martensite, steel sample is quenched into a bath of liquid nitrogen. The process is called cryogenic treatment of material.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Flame Hardening The process consists of heating the surface of medium carbon steel by high temperature gas flame at 2400\u00b0C<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1578,10],"tags":[1610,1609],"class_list":["post-4997","post","type-post","status-publish","format-standard","hentry","category-engineering-materials","category-me","tag-flame-hardening","tag-oxyacetylene-torch"],"_links":{"self":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/4997","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/comments?post=4997"}],"version-history":[{"count":0,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/4997\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/media?parent=4997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/categories?post=4997"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/tags?post=4997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}