Electric Arc Welding by Ernest Wanamaker Harry R. Pennington

Author:Ernest Wanamaker , Harry R. Pennington
Language: eng
Format: epub, pdf
Publisher: Simmons-Boardman
Published: 1921-03-25T05:00:00+00:00

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Fig. 50—Test Pieces for Tensile, Cold Bend and Fatigue Specimens

together with certification that all electrodes bearing this trade-name will be substantially the same as the sample submitted, and such other information as is deemed necessary by the purchaser.

Plate Material. —Standard % in. ship-plate, as adopted by the American Society of Testing Materials, A 12-16 (page 98, A. S. T. M. Standards, 1918), are specified for the test.

The plates from which tensile, cold-bend and fatigue specimens are to be made shall be cut into pieces 9 in. by 30 in., as shown in Fig. 50.

The plates from which impact specimens are to be made shall be cut into pieces 30 in. by 30 in., as shown in Fig. 51.

Number of Test Welds. —One 30 in. weld for the tensile, cold-bend and fatigue test shall be made, as indicated in Fig. 50.

Three 30 in. test welds for the impact test shall be made, as indicated in Fig. 51.

Preparation of Plates for Physical Test —(a) Each test weld shall be machined down on both sides to about the surface of the plate.

(b) Specimens shall be cut from each test weld reserved for physical tests, as follows:

1. Three tensile specimens—these shall be machined to a uniform width of 1% in. unless a weld of great strength makes it necessary to leave shoulders at the ends, in which case the standard A. S. T. M. test specimens for sheet iron and steel shall be prepared.

ELECTRIC ARC WELDING

2. Three cold-bend specimens—these shall be machined to a uniform width of 1% in.

3. Six fatigue specimens—these shall be machined to about Y^ in. diameter and 10 in. long. (The exact dimensions are to be determined by experiment.)

Physical Tests. —(a) Tensile Strength. The three specimens shall be tested in accordance with the practice recommended by the A. S. T. M. and shall include the determination of the tensile strength, yield point (by drop-of-beam method), reduction of area and total elongation after rupture in 2 in. and 8 in.

(b) Cold-bend Test. —This test shall be made by placing the specimen

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Fig. 51—Test Pieces for Impact Specimens

on two ball-bearing rollers with the apex of the "V" upward and midway between the rollers and loaded at the center of thje span thus formed by a cylindrical surface having a diameter of 1% in. This surface shall bend the specimen downward between the rollers until a fracture appears on the lower side of the specimen. The loading shall then be stopped and the angle noted through which the specimen has been bent.

(c) Fatigue Test —Each of the six specimens shall be tested in a special rotating type of machine similar to that used by Lloyd's Register of Shipping. (Exact details to be determined by experiment.)

(d) Impact Test. —Each impact test specimen shall be placed on supports 18 in. high and 4% ft. apart. A spherical weight of 500 lb. shall be allowed to fall freely through a distance of 10 ft.

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