NF EN 757

La présente norme décrit les méthodes d'essais à effectuer pour vérifier la symbolisation des électrodes enrobées pour soudage électrique à l'arc déposant un métal à haute limite d'élasticité. Elle complète donc la norme NF A81-340 qui précise cette symbolisation. Certains essais spéciaux tels que le dosage de l'hydrogène diffusible, la détermination du rendement, l'analyse chimique du métal déposé font l'objet des normes dont les références sont respectivement : NF A 81-305, NF A 81-306, NF A 81-304.

<p>ISO 18275:2011 specifies requirements for classification of covered electrodes and deposited metal in the as-welded condition and in the post-weld heat-treated condition for manual metal arc welding of high-strength steels with a minimum yield strength greater than 500 MPa or a minimum tensile strength greater than 570 MPa.</p> <p>ISO 18275:2011 is a combined specification providing a classification utilizing a system based upon the yield strength and an average impact energy of 47 J of the all-weld metal, or utilizing a system based upon the tensile strength and an average impact energy of 27 J of the all-weld metal.</p> <ol> <li> Subclauses and tables which carry the suffix letter "A" are applicable only to covered electrodes classified under the system based upon the yield strength and an average impact energy of 47 J of the all-weld metal given in ISO 18275:2011.</li> <li> Subclauses and tables which carry the suffix letter "B" are applicable only to covered electrodes classified under the system based upon the tensile strength and an average impact energy of 27 J of the all-weld metal given in ISO 18275:2011.</li> <li> Subclauses and tables which do not have either the suffix letter "A" or the suffix letter "B" are applicable to all covered electrodes classified under ISO 18275:2011.</li> </ol>