{"id":17632,"date":"2022-11-10T10:02:28","date_gmt":"2022-11-10T09:02:28","guid":{"rendered":"https:\/\/mollificiovalli.it\/fabbricazione-delle-molle-materiali-usati\/"},"modified":"2023-04-13T08:44:54","modified_gmt":"2023-04-13T07:44:54","slug":"fabbricazione-delle-molle-materiali-usati","status":"publish","type":"post","link":"https:\/\/mollificiovalli.it\/en\/fabbricazione-delle-molle-materiali-usati\/","title":{"rendered":"SPRING MANUFACTURING : WHICH MATERIALS ARE USED"},"content":{"rendered":"

Let’s make a rundown of the materials used in spring manufacturing<\/strong> and the way in which they are made; knowledge is a prerequisite to deepen the causes of failure related to surface defects.<\/p>\n

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\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Read also: WHY DOES A SPRING BREAK?<\/a><\/em><\/strong><\/p><\/blockquote>\n

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What are the features of the materials used for spring manufacturing and, more generally, for the elements with elastic characteristics? They must have high yield resistance<\/strong>, so that the Hooke diagram<\/em> elastic area is as wide as possible.<\/p>\n

In theory the ideal elastic material is the one in which the yield resistance coincides with the Rm<\/em>, that is which one that maintains the proportionality between stress and deformation<\/strong> until it breaks down.<\/p>\n

In spring manufacturing materials, the yield resistance (Rp02<\/em>) is about 70% of the Rm<\/em>, which is already a considerable value if compared to that one of other materials with non-elastic uses. The safety coefficients adopted for generic structural steels are much higher than 0.7. Just to be clear: K = 1 \/ 0.7<\/em> is the value to use to divide the rupture \u03c3<\/em> (Rm<\/em>), to calculate the maximum \u03c3<\/em> which must not be exceeded using a certain material.<\/p>\n

Materials for springs manufacturing have an extremely high<\/strong> Rm<\/em> and therefore have an equally high<\/strong> Rp02<\/em>.<\/p>\n

For compression\/traction springs for which the material stress is not axial (\u03c3)<\/em>, but tangential, the tangential forces (\u03c4)<\/em> shall be considered, that is those which arise in the event of shear strain.<\/p>\n

For these materials the conventional rule is to consider 45% of Rm<\/em> as \u03c3 max<\/em>, even if the responsible strain for yielding is \u03c4<\/em>.<\/p>\n

Furthermore, the block settling operation<\/strong>, which forces the material to outreach its elastic-plastic<\/em> area, reporting a permanent deformation, increases the limit of use by about 10%, reaching 55-56% of Rm<\/em>.<\/p>\n

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As mentioned, spring materials must have a high Rm and therefore the question is: how to obtain materials with high<\/strong> RM<\/em>? And what structural chemical characteristics must these materials have?<\/p>\n

The prerequisite for materials with high Rm<\/em> is the presence of carbon<\/strong> in the chemical analysis. Then the mechanical characteristics are obtained in two different ways:<\/p>\n