{"id":17946,"date":"2023-01-17T15:49:26","date_gmt":"2023-01-17T14:49:26","guid":{"rendered":"https:\/\/mollificiovalli.it\/the-surface-condition-of-wire-anomalies-that-can-damage-springs\/"},"modified":"2024-02-05T09:08:27","modified_gmt":"2024-02-05T08:08:27","slug":"the-surface-condition-of-wire-anomalies-that-can-damage-springs","status":"publish","type":"post","link":"https:\/\/mollificiovalli.it\/en\/the-surface-condition-of-wire-anomalies-that-can-damage-springs\/","title":{"rendered":"THE SURFACE CONDITION OF WIRE: ANOMALIES THAT CAN DAMAGE SPRINGS"},"content":{"rendered":"

Let’s discuss factors related to material manufacturing processes<\/strong> that can lead to spring failure. During wire production, defects<\/strong> can arise that affect the wire’s quality, specifically those related the surface condition of wire<\/strong>.<\/p>\n

\n

Also read: THE MATERIAL STRUCTURE: HOW IT AFFECTS THE QUALITY OF SPRINGS<\/a><\/p>\n<\/blockquote>\n

Surface condition of wire<\/h1>\n

Most spring failures due to fatigue<\/strong> are caused by defects in this area. These defects can arise during the billet<\/em>-to-rod<\/em><\/a> (LINK WIKIPEDIA) or rod<\/em>-to-wire drawing process.<\/p>\n

The main surface defects are as follows:<\/p>\n

Seams<\/h2>\n

These are the zones where solidification fronts meet in the billet<\/em>. These can be prevented by using magnetic fields<\/strong> that rotate the liquid fraction in the billet<\/em>, making solidification uniform.<\/p>\n

Roundness defects<\/h2>\n

These defects are created by play between the drawing dies during billet<\/em>-to-rod<\/em> drawing. They are responsible for surface cracks.<\/p>\n

Localized martensite<\/h2>\n

This is caused by localized heating due to lubrication<\/strong> defects between the wire and the drawing die surface.<\/p>\n

Corrosion (generalized, intergranular, pitting<\/em>)<\/h2>\n

This compromises surface integrity, can cause cracks, and initiate fractures<\/strong>.<\/p>\n

Scratches, flakes, folds<\/h2>\n

Scratches occur during wire drawing<\/strong> due to lubrication problems or advancement speed.<\/p>\n

Flakes appear as scales on the wire’s surface<\/em>, which can be caused by corrosion or uneven<\/strong> cooling.<\/p>\n

Folds occur when metal is overlapped at cold temperatures, creating non-bonded layers. These occur when there are rolling edges on the wire<\/em>, which are portions of material created during extrusion when the two semi-shells of the rolling dies are not perfectly adherent to each other and material infiltrates the space that forms between the surfaces. This type of defect falls under the roundness defect<\/strong> classification, which transforms into a fold when this extra material is folded and compressed onto the main surface during wire drawing.<\/p>\n

Cold abrasions<\/h2>\n

These harden the material and form martensite, whose effects have already been explained.<\/p>\n

Burns<\/h2>\n

These may be present on the wire<\/em> due to grinding problems on the billet<\/em>.<\/p>\n

Cracks<\/h2>\n

A crack is a fissure that compromises the structural integrity<\/strong> of the material. Cracks can be found both inside the material and on its surface. Surface cracks are certainly the most dangerous<\/strong> for fatigue resistance.<\/p>\n

\"SPING

Cracks can form for various reasons, among which the following are the most well-known and recurring.<\/p>\n

Quenching<\/h3>\n

Due to improper cooling during quenching, the volume change between austenite and martensite can create cracks.<\/p>\n

Mechanical processing that creates mechanical stress on the material<\/h3>\n

In this case, surface imperfections are crack initiation zones.<\/p>\n

Internal fissures<\/h3>\n

Due to excessive wire drawing or overheating of the wire during wire drawing.<\/p>\n

Intergranular fractures<\/h3>\n
    \n
  • Caused by folds, as seen in a previous point.<\/li>\n
  • Caused by seams.<\/li>\n
  • Caused by corrosion and stress corrosion cracking<\/em>.<\/li>\n<\/ul>\n

    In this article and in the previous one, we attempted to create an exhaustive list of the defects present in the raw materials, analyzing the causes and phases of occurrence in the production process from melting to finished product<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Let’s discuss factors related to material manufacturing processes that can lead to spring failure. During wire production, defects can arise that affect the wire’s quality, specifically those related the surface condition of wire. Also read: THE MATERIAL STRUCTURE: HOW IT AFFECTS THE QUALITY OF SPRINGS Surface condition of wire Most spring failures due to fatigue […]<\/p>\n","protected":false},"author":5,"featured_media":17371,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[318,332],"tags":[],"class_list":["post-17946","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news-en","category-technical-articles"],"_links":{"self":[{"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/posts\/17946","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/comments?post=17946"}],"version-history":[{"count":0,"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/posts\/17946\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/media\/17371"}],"wp:attachment":[{"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/media?parent=17946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/categories?post=17946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mollificiovalli.it\/en\/wp-json\/wp\/v2\/tags?post=17946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}