ASME SA-370:2019 pdf free download

ASME SA-370:2019 pdf free download.TEST METHODS AND DEFINITIONS FOR MECHANICAL TESTING OF STEEL PRODUCTS.
When this pomi is reached, the free-running rate of separation of the crossheads shall be adjusted so as not to exceed in. per mm per inch of reduced section. or the distance between the grips for Lest specimens not having reduced sections. This speed shall be maintained through the yield point or yield strength. In determining the tensile strength, the free-running rate of separation of the heads shall not exceed in. per mm per inch of reduced section. or the distance between the grips for test specimens not having reduced sections. In any event, the minimum speed of testing shall not he less than the specified maximum rates for determining yield point or yield strength and tensile strength.
7.4.2 It shall be permissible to set the speed of the testing machine by adjusting the free running crosshead speed to the above specified values, inasmuch as the rate of separation of heads under load at these machine settings is less than the specified values of free running crosshead speed.
7.4.3 As an alternative, if the machine is equipped with a device to indicate the rate of loading. the speed of the machine from halt the specified yield point or yield strength through the yield point or yield strength may be adjusted so that the rate of stressing does not exceed 1(M) (XX) psi (69(1 MPat/min. However, the minimum rate of stressing shall not be less than 10 (MX) psi (70 MPa)/min.
8. Test Specimen Parameters
8.1 Selection — Test coupons shall be selected in accordance with the applicable product specifications.
8.1.1 Wrought Steels Wrought steel products are usually tested in the longitudinal direction, hut in sonic cases, where size permits and the service justifies it. testing is in the transverse, radial, or tangential directions (see Fig. I and Fig. 2).
8.1.2 Forged Steels — For open die forgings, the metal for tension testing is usually provided by allowing extensions or prolongations on one or both ends of the forgings. either on all or a representative number as provided by the applicable product specifications. Test specimens arc normally taken at mid-radius. Certain product specifications permit the usc of a representative bar or the destruction of a production part for test purposes. For ring or disk-like forgings test metal is provided by increasing the diameter, – thickness, or length of the forging.
13.4.4 Elongation at fracture is defined as the elongation measured just prior to the sudden decrease in force associated with fracture. [or many ductile materials not exhibiting a sudden decrease in force, the elongation at fracture can be taken as the strain measured just prior to when the force falls below lO of the maximum force encountered during the test.
13.4.4.1 Elongation at fracture shall include elastic and plastic elongation and may be detennined with auto- graphic or automated methods using extensonleters verified over the strain range of interest. Use a class B2 or better extensorneter for materials having less than 5% elongation; a class C or better extensometer for materials having elongation greater than or equal to 5% hut less than 50%; and a class D or better extensometer for materials having 50% or greater elongation. In all cases, the exensomeer gage length shall be the nominal gage length required for the specimen being tested. Due to the lack of precision in fitting fractured ends together, the elongation after fracture using the manual methods of the preceding paragraphs may differ from the elongation at fracture determined with extensomctcrs.
13.4.4.2 Percent elongation at fracture may be calculated directly from elongation at fracture daa and be reported instead of percent elongation as calculated in 13.4.1. However, these Iwo parameters are not interchangeable. Use of the elongation at fracture method generally provides more repealable results.