The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

eR May, 1909 COMPARISON OF TESTING REQUIREMENTS FOR STEEL: USED IN Ef : LAID DOWN BY THE ENGINEEL IN THE CONSTRUCTION OF SHIPS AND THEIR MACHINERY EERING STANDARDS COMMITTEE! : TENSILE TESTS, BEND TESTS. MATERIAL. Tensile Breaking Minimum. Extension por Standard Strength, S y Rane aie e cent, on eee Test aa Number. Sizo of Test Piece. Radius of Bend Anglo of Test Number. MANUFACTURE. STEEL PLATES :-- For Ships * 28-32 20 for -375" and above. A "1 each charge, 2 i i ' D and 4 ge, 2 if Not less than I}ins. | Equal to 1-5 times 180° 1 cold or 1 temper fi Open Hearth, Acid 16 Welw 2ee8 hace cua eee : : : per from | Open Hearth, Acid or Bhine (ler coli Augie 26232 ; g ns. wide thickness, ' each plate as rolled. Basic. , Ships (for cold fla 2 ) Do a Do. Do Do, 180° 1 cold from each plate. Do. , Marine Boilers .. 28-32 0 < BN is above, A 1 cach plate. Plates Do. Do. 130° 1 cold or 1 temper from Do. , Marine Boilers (for flanging) .. 26-30. 23 for sve end éhove A over 2} ers 1 each end. D : each plate as rolled. (f) eden aie é 0. 0 Do. 180 Do. , Do, Stee. Bars AND SecT MATERIAL '-- . Qktnc 29-- ..QaRH ' For Ships... a ~ 28-33 a ee above. A or B 1 each charge, 2 if Do. Do. 180° 1 cold or 1 temper from Do. VO charge exceeds %5 tons. each Bar a Section > Marine Boilers (Angles and T 28-32 20 for 375" and above. A 2 each ch 2 Res a Phan sar each charge (c) Do. Do. 180 Do, Do. Marine Boilers (Combustion 26-30 23 for -375" and above.| Bor F Do. §(¢c : "and « Mel i ) Do. Do. 180° 1 cold and 1 temper from Do. Chamber Stays) 20 below -375" (a) every 15 Bats as rolled. from each charge. Sree Rivet Bars --- For Ships 25-30 25 1 each charge (d) = - -- _ Do. ., Marine Boilers 26-30 25 (s) 2 each charge. (c) = _ - _ Do. Strrei. Forermas :-- . " wi "75" thi 2 ' 180° " For Marine Work 28-40 29-17 1" wide by -7. ick | Up gn eee? oe 80' At ee . = each Not more than 4 tons Quality Factor C or D At least 1 each Do. Above 32 up to 36 180° Do. Bete nan a 57 forging tons max. tensile. -375"| ~ Do. min, specified. Do. Above 36 up to 40 180° Do, tons max. tensile. -625" Srezt Castines .-- & For Marine Work, Grade A eon a ©, D, or E | At least 1 each charge Do. i" 60° | At least 1 cold each Do. (m). ' charge (m). Do. B 26-35 20 Do. If casting made from Do 1" 120° If casting made from Do. more than 1 charge, more than | charge, at Do. C 26-35 2B Do. "ae ee bee Do. Vv 90° least 4, Do. Do Doce s. A co .- es ne fs ae ae we Do. (a) When tested on gauge length of 4 dia. (test piece F) the elongation shall be 28 and 24 per cent, respectively. from one charge exceeds. 15, one additional test for each further 15 or portion thereof. shall be 50:in place of 15. 10 tons, or portion thereof. castings, 1 shall be 30 per cent. having a gage length of four times the diameter, for bars having a diam- eter over 1 in., the equivaient e1onga- tion being approximately one-fifth more than that for a test piece hav- ing a gage length of eight times the diameter. It frequently happens that an 8-in. gage length is impracticabte for castings and forgings for marine work, so that standard test pieces ot fixed gage lengths of 2, 3 and 3% in. with areas of %4, % and 3% of a sq. in. respectively (test pieces C, D and E) have been. adopted to meet these cases. The extensions on these test pieces are not directly comparable with those obtained on the test pieces adopted for rolled structural material (test pieces B and F), but are directly comparable with each other. a In addition to test pieces for the purpose of ascertaining the tensile strength, standard bend test pieces for marine castings and forgings have also been devised. A considerable amount of experimental work was carried out in this connection, but it was consid- ered preferable to recommend three dimensions for the internal diameter of the bend, as follows: Diameter of oe Range of tensile strength. Bend. Per Square Inch. Inches. = Brom 28 up to 32 tonsS....-++-+++s-+**? 3 Above 32 and up to 36 tons....-- oe ag Above 36 and up to 40 tons....-- for each pouring head. *Tons of 2,240 By the. introduction of the standard test pieces the engineering standards committee has not merely facilitated the work of the test room and re- lieved the steel makers to a very large extent from the expense of preparing different sized specimens of the saine steel to comply with the various reg- ulations of the several inspecting bod- ies, but by rendering test results com- parable they will have placed at the disposal of the next generation of en- gineers and. ship builders a mass of valuable information which would not otherwise have been: available. Breaking Stresses and Etongations. The standard test pieces having been decided upon, it now became pos- sible for the committee to deal with the breaking stresses and elongations to be demanded. The table appended to this paper shows in a few lines, and more clearly than pages of printed matter, that the committees set before them a high ideal as to the nature of the tests to be demanded and indicates, as the re- sult of a great amount of work and discussion, the extent to which they have been successful in harmonizing hitherto divergent tests. The letter press of the standard re- quirements led to a considerable amount of discussion, but as the Brit- sh admiralty, the board of trade, and from opposite . ends. (m) Small (Test-piece F) the elongation the three classification societies had all published very full and carefully thought out rules, it became largely a question of welding these into one, which was eventually and successfully done. We made our report upon the material for ships and boilers in De- cember, 1904, and these reports were also accepted simpliciter. Standardizing Tests for Iron. The committee had also before them . the advisability of standardizing tests for iron, and. this work. is still) in hand, but has not made such progress - as we would all have desired. Up till now, none but practical tests have been made obligatory by any of the | classification societies except one; that is to say, that no test pieces were re- quired to be broken or bent before delivery of the material, as in the case » of steel. It is also true that iron is not now a general constructional ma- terial for ships or boilers, still it is used inthe case of anchors and cables, rigging chains, slings and_ general smith work, and the committee have - felt it desirable, and they are now en- gaged in making an attempt to stand- ardize a few clearly defined classes of iron. There are a great number of different. marks, or brands, of iron, and by these marks it has hitherto been sold. We are informed by the iron makers that it is impossible to (c) When number of bars ( In round bars of 134 dia. and under the number (d) When weight of bars exceeds from one charge 10 tons, one additional test for each further (f). Plates over 2% tons, one cold and one temper, (s) When tested on gauge length of 4 dia. Ibs.