{"id":1220,"date":"2025-02-26T15:00:24","date_gmt":"2025-02-26T15:00:24","guid":{"rendered":"https:\/\/expanite.com?p=1220"},"modified":"2025-04-11T09:47:16","modified_gmt":"2025-04-11T09:47:16","slug":"galling-and-corrosion-resistance-on-fittings","status":"publish","type":"post","link":"https:\/\/expanite.com\/fr\/amelioree-grippage\/","title":{"rendered":"R\u00e9sistance am\u00e9lior\u00e9e au grippage et \u00e0 la corrosion sur les raccords "},"content":{"rendered":"\r\n

(Article en anglais)\r\n\r\nThe processes for surface hardening of stainless steel from the Danish pioneer Expanite, has in recent years been used more and more frequently when it comes to improving galling and corrosion resistance of stainless steel fittings. The results of a long-term corrosion test show in particular the superiority of the Expanite technology over traditional methods.<\/strong><\/em><\/p>\r\n \r\n

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\r\n\r\nA horror for every assembler: galling of stainless steel fittings. A drop of lubricant on the thread helps; but what if, due to for example hygienic requirements, no lubricants may be used, or it is simply forgotten? Stainless steel, with its excellent corrosion resistance, has the disadvantage that when having steel-to-steel contact, it tends to gall. Applying coatings such as DLC or diffusion processes such as Kolsterising\u00aecarburizing, nitrocarburizing or plasma nitriding have proven effective in counteracting this effect. However, these processes are not only very costly but also generally have a negative effect on corrosion resistance.\r\n\r\n\r\n\r\n<\/div>\r\n \r\n

Improved corrosion resistance<\/em><\/h2>\r\n With its processes specially developed for stainless steel, Expanite has overcome this dilemma, using its patented technology to improve corrosion resistance of components during hardening and at the same time make them resistant to wear and galling. In this context, TCW Anlagenbau located in Germany recently carried out extensive long-term corrosion tests on different stainless steel grades. While the traditionally hardened components made of 316Ti (1.4571) (pic 2) show a comparatively strong corrosion attack in the salt bath after a short time, the fittings 316Ti (1.4571) and cutting rings 316Ti (1.4571 & 1.4462) treated with the SuperExpanite show no corrosion even after two months in 10% salt bath solution. In the case of 303 (1.4305), which is basically less resistant, a tendency towards improvement in corrosion resistance could be demonstrated: the unhardened nozzle (pic 4) shows a significantly stronger corrosion attack than the component treated with the Expanite process (pic 5).\r\n\r\n \r\n

Sustainable against wear and galling<\/em><\/h2>\r\n \u00ab\u00a0Galling of stainless steel components is a well-known problem and we regularly hear from our customers about cases where the galling of a classic screw connection means that entire component have to be replaced at great expense\u00a0\u00bb<\/em>, explains Dr. Holger Selg, Expanite Sales Director DACH and application expert, and adds: \u00ab\u00a0Ideally, both friction parts are treated with the SuperExpanite, but hardening only one component already provides a significant improvement in terms of galling resistance.\u00a0\u00bb<\/em> The relatively low hardness of stainless steel also makes corresponding components susceptible to abrasive wear. Here, too, the surface hardening of Expanite provides a remedy and extends the service life compared to unhardened stainless steel components. \u00ab\u00a0Sustainability is playing an increasingly important role,\u00a0\u00bb says Dr. Selg \u00ab\u00a0Expanite also scores points over comparable wear protection processes with a significantly more energy-efficient and environmentally friendly gas-based diffusion process that does not require time-consuming cleaning of the parts, e.g. with aggressive chemicals after hardening.\u00a0\u00bb\r\n\r\n \r\n

Broad spectrum of materials<\/em><\/h2>\r\n The Expanite technology, specially developed for corrosion-resistant materials, offers a solution for austenitic, martensitic, ferritic and duplex stainless steels as well as for nickel-based alloys such as Inconel\u00ae and Hastelloy\u00ae. Moreover, ExpaniteHard-Ti, which the Expanite team of experts has developed to market maturity in recent years, is used for titanium grades.\r\n\r\n\r\n\r\n<\/div>\r\n \r\n
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Pic 1: Components in 316Ti (1.4571) treated with traditional hardening process<\/em><\/strong><\/figcaption><\/figure>\r\n<\/div>
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Pic 2: 316Ti (1.4571) fittings without and with Expanite treatment<\/em><\/strong><\/figcaption><\/figure>\r\n<\/div>
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Pic 3: Cutting rings in Duplex (1.4462) hardend with\/without SuperExpanite<\/em><\/strong><\/figcaption><\/figure>\r\n<\/div>
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Pic 4: 303 (1.4305) nozzle without treatment<\/em><\/strong><\/figcaption><\/figure>\r\n<\/div>
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Pic 5: SuperExpanite treated nozzle out of 303 (1.4305)<\/em><\/strong><\/figcaption><\/figure>\r\n<\/div>\r\n\r\n<\/div>\r\n\r\n\r\n<\/div>\r\n \r\n

About Expanite<\/em><\/h2>\r\n \r\n

Expanite offers state-of-the-art solutions for surface hardening treatment of stainless steels and titanium.\r\nWith Expanite’s processes, it is possible to increase the material\u2019s surface hardness tenfold while at the\r\nsame time maintaining and even increasing its corrosion resistance. Expanite is a global organization with\r\na combined development and production facility near Copenhagen, Denmark, and hardening capacity in\r\nboth US, Germany, Korea and China. Expanite’s solutions are flexible and can be introduced directly into a\r\ncustomer\u2019s own production line as part of a licensing arrangement. Learn more on www.expanite.com<\/a><\/em>.<\/p>\r\n \r\n

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Download PDF<\/strong><\/a><\/div>\r\n\r\n\r\n<\/div>\r\n  \r\n\r\n","protected":false},"excerpt":{"rendered":"

(Article en anglais) The processes for surface hardening of stainless steel from the Danish pioneer Expanite, has in recent years been used more and more frequently when it comes to improving galling and corrosion resistance of stainless steel fittings. The results of a long-term corrosion test show in particular the superiority of the Expanite technology […]<\/p>\n","protected":false},"author":2,"featured_media":2117,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-1220","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-press"],"_links":{"self":[{"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/posts\/1220","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/comments?post=1220"}],"version-history":[{"count":10,"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/posts\/1220\/revisions"}],"predecessor-version":[{"id":3877,"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/posts\/1220\/revisions\/3877"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/media\/2117"}],"wp:attachment":[{"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/media?parent=1220"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/categories?post=1220"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/expanite.com\/fr\/wp-json\/wp\/v2\/tags?post=1220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}