ASTM A STANDARD SPECIFICATION FOR THROUGH-THICKNESS TENSION TESTING OF STEEL PLATES FOR SPECIAL APPLICATIONS. ASTM A A M – Designation: A /AM – 03 Standard Speci? cation for Through-Thicknes. copy of ASTM A is included in Appendix A of this report. In the process of . of a rolled W-shape that is made of ASTM A Grade 50 steel.
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A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. The principal purpose of the testing is to provide a measure of the resistance of a steel plate to lamellar tearing.
Within the text, the SI units atsm shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently a770 the other. Combining values from the two systems may result asm nonconformance with the speci? However, unless the order speci? A Test Methods and De? Current edition approved May 10, Originally approved in Last previous edition approved in as A — 86 Two tests shall be required from each quenchedand-tempered plate.
The tests shall be representative of the plate in its? It does not refer to the condition of asm plate. Take the test coupons from the center of the plate width. The joining method used shall be one which results in a minimal heat-affected zone in the portion of the plate to be tested.
Shielded metal arc, friction, stud, or electron-beam welding methods have proven to be suitable. For Types 1 and 2 specimens, locate the center of the length of the reduced section at the approximate mid-point of the plate thickness. For Type 3 specimens, locate the weld astj line of one plate surface within 1?
The Type A specimen provides a reduced section length greater than the plate thickness. The Type B specimen provides a reduced section length of 21? Over a minimum plate thickness determined by the specimen end con?
For plates over 41? For plates over 6 in. The number of tests required will depend upon the thickness of the plate being tested and the reduced section length selected. A series of two or more Type F specimens may be used to cover the full thickness of the plate.
Athough thickness tension test – ASTM (testing materials) Code Issues – Eng-Tips
The length of the reduced section Aas shown in Fig. Within the plate thickness dimension speci? In all cases, the minimum length of the reduced section must be as speci? See Test Methods and De? Tensile Strength Requirements S1. Yield Strength Requirements S2.
Reduction of Area Requirements S3. Number of Tests S4. Location of Test Coupons S5. It is generally caused by strain induced in the thickness direction resulting from shrinkage of the weld deposit and by the restraint imposed by the components that comprise the weldment. High restraint increases the possibility of lamellar tearing. However, lamellar tearing is not solely con? Lamellar tearing may also result from loads on the plate surface.
The tearing may remain completely subsurface or appear at plate edges or at weld toes. Strains in the through-thickness direction can cause individual inclusions to fractures or decohere from the surrounding steel matrix, thus initiating a void. Further strain can cause the remaining metallic ligaments to shear or rupture, resulting in the step-like fracture appearance. On the other hand, a reduction in the magnitude and concentration of these inclusions to a low level tends to preclude any easy fracture path along the low ductility inclusions and the steel exhibits improved ductility in a throughthickness direction.
In silicon semikilled or fully killed steels, these inclusions are primarily oxides present as silicates and sul? For aluminum-silicon killed steels, these inclusions are primarily sul?
To improve the through-thickness ductility and thus the resistance of the steel to lamellar tearing, it is necessary to reduce the level of the nonmetallic inclusions.
To provide a high resistance to lamellar tearing may require the use of special steel-making processes that can reduce the oxygen and sulfur contents in the steel to very low levels. The more common processes, used singly or in combination, are: The steelmaking processes are not all intended for the same purpose, but will improve the through-thickness ductility to various degrees depending on the process used.
The most widely accepted method of measuring the material ductility factor of susceptibility to lamellar tearing is the reduction of area of a round tension test specimen oriented perpendicular to the rolled surface of a plate.
This scatter of test results is due in part to the inherent variability of the distribution of the nonmetallic inclusions discussed in X1. For example, those nonmetallic inclusions that form during the solidi? Some of these factors are discussed in X2. Operator technique will also be a factor in increasing astj, particularly in the measurement of the?
Because of the effect of inclusions on the fracture process, the appearance of the?
ASTM A770/A770M – 03(2012)E1
The number of tests and test positions have not been established that would provide a good estimate of both the mean and the variability of through-thickness tensile reduction of values of a plate. The intent of this speci?
The potential variability of the test results also increases the possibility that subsequent testing of a steel plate quali? Astmm is generally accepted that there is a diameter effect on reduction-of-area values such that a smaller diameter specimen generally yields a higher average reduction in area value.
It is also accepted that smaller diameter test specimens will tend to give greater variability to the resulting reduction in area values. Because these relationships between the test specimen diameter and the average and variability a70 the test result have not been satisfactorily quanti?
This minimum value may be from 1. Below this minimum value, the reduction at the failure point in the reduced section is restrained by the larger cross section away from the reduced section. A minimum slenderness ratio of 2 was selected for the standard Type 2 specimen to allow a 0.
A minimum slenderness ratio of 2. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
This x770 is subject to revision at any time by the responsible technical committee and must be reviewed every? Your comments are invited either for revision of this standard or for additional standards and should be awtm to ASTM International Headquarters.
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