Temas Variados / EnsayosEnsayosEnsayos de Calidad: EnsayosEnsayos de Calidad, Tareas, Monografias - busque más de 840.000+ documentos.
Enviado por: cjvr85 21 julio 2011
Palabras: 3070 | Páginas: 13
Views: 614
11.6.2 Due to the specimen geometry effect encountered when using full-section test specimens for angles, the elongation requirements for structural-size angles shall be increased by six percentage points when full-section test specimens are used. 11.6.3 Due to the inherently lower elongation that is obtainable in thicker material, adjustments in elongation requirements must be provided. For material over 3.5 in. [90 mm] in thickness, a deduction of 0.5 percentage point from the specified percentage of elongation in 2 in. [50 mm] shall be made for each 0.5–in. [12.5–mm] increment of thickness over 3.5 in. [90 mm]. This deduction shall not exceed 3 percentage points. Accordingly, the following deductions from the base elongation requirements shall apply: Nominal Thickness Range, in. [mm] Elongation Deduction,% 3.500—3.999 [90.00—102.49] 0.5 4.000—4.499 [102.50—114.99] 1.0 4.500—4.999 [115.00—127.49] 1.5 5.000—5.499 [127.50—139.99] 2.0 5.500—5.999 [140.00—152.49] 2.5 6.000 and thicker [152.50 and thicker] 3.0 11.6.4 When so stated in the material specification, for plates up to 3⁄4 in. [20 mm], inclusive, in thickness, if the percentage of elongation of an 8-in. [200-mm] gage length test specimen falls not more than 3 percentage points below the amount prescribed, the elongation shall be considered satisfactory, provided the percentage of elongation in 2 in. [50 mm] across the break is not less than 25 %. NOTE 5—A characteristic of certain types of alloy steels is a local disproportionate increase in the degree of necking down or contraction of the specimens under tension test, resulting in a decrease in the percentage of elongation as the gage length is increased. The effect is not so pronounced in the thicker plates. 11.6.5 The tensile property requirements tables in many of the material specifications covered by this general specification specify elongation requirements in both 8-in. [200–mm] and 2-in. [50–mm] gage lengths. Un
less otherwise provided in the individual material specification, both requirements are not required to be applied simultaneously and elongation need only be determined in gage length appropriate for the test specimen used. After selection of the appropriate gage length, the elongation requirement for the alternative gage length shall be deemed not applicable. 11.7 Yield Strength Application: 11.7.1 When test specimens do not exhibit a well-defined disproportionate yield point, yield strength shall be determined and substituted for yield point. 11.7.2 The manufacturer or processor shall have the option of substituting yield strength for yield point if the test specimen exhibits a well-defined disproportionate yield point. 11.7.3 Yield strength shall be determined either by the 0.2 % offset method or by the 0.5 % extension-under-load method. 11.8 Product Tension Tests—This specification does not provide requirements for product tension testing subsequent to shipment ( ... |
