リムを超耐熱鋼 LCN-155 で作れる大型複合車盤の製造研究

概要

論文の詳細を見る
(1) To establish the production technique of the large forgings of the super-high grade heat-resisting steel LCN-155 and its weldings, the authors studied, experimentally on manufacturing the large composite wheel, of which rim is made of LCN-155, outer dia. 600×inner dia. 300×thickness 60mm, and of which the boss is made of Car-Mo steel. (2) After several tests with small capacity furnace, they melted LCN-155 by a 2-ton high frequency induction furnace, especially investigating raw materials and melting conditions, and casted the octagonal 350kg ingots. (3) After enough diffusion annealing of these ingots, they forged and swaged them cautiously, checking the temperature and the methods of forging, but the cracks were found at the end surface while swaging φ8"×length 540mm→φ270×length 330mm by 2, 000 ton hydraulic press. According to the results of macro-and micro-structure examinations, these cracks were considered to be caused by "inner wrinkles" due to the enomous segregations of the impurities, carbides and others. (4) Referring to the previous test, they melted LCN-155 again by 2 ton induction furnace, swaged, core-punched, ring-forged and at last succeeded to make up the rim without any cracks. (5) Before welding, they solution-treated the rim at 1, 200℃ and annealed the boss. After welding they heated the wheel at 800℃×24h followed by furnace cool, which represented both of stress-relief and aging of the rim. (6) Because they could not obtain the welding rods of AISI 309 Cb in both of domestic and abroad markets at that time (1953-4), they made trial manufacture of the coiled φ1.6mm wires for sigma welding from melting to wire-drawing. (7) For the grooves which were designed by many preliminary welding results, they performed the sigma welding semi-automatically ; but, for the reason that the size and the quality of rod were not sufficiently uniform, welding was often stopped. In the result the deposits were unsatisfactory and ununiform. Therefore, they used AISI 310 rods of Linde Co. for welding the opposite side. (8) It was very difficult to cut this welded wheel. The welding of the deposits was observed to be not good by the macro-structure test for the longitudinal section of the wheel. (9) For these super-high grade heat-resisting steels, it was better to be welded by the similar metal rods, so they prepared the rim and boss of same dimension and LCN-155 φ5mm welding rods, and welded by the argon-arc tungsten method, checking the welding procedure in detail. (10) By macro-and micro-structure tests for the longitudinal section, it was observed that the deposits were well welded. Consulting with the high temperature mechanical test results, they confirmed that the mechanical strength of the rim, which was exposed at high temperature, corresponded well to that of boss which was rather kept at lower temperature. However, without checking by the spin test, they cannot mention at present about the influences of the low elongation, contraction and impact values when the test pieces break at the deposits. (11) By these studies the authors could complete the large composite wheel as aimed at the first time, of which rim became superior in the material quality through core-punched and ring-forged, and could resist up to about 750∿800℃. Also they could save 1/3∿1/4 quantity of the expensive heat-resisting steel in the composite wheelas compared with the solid wheel.
社団法人日本鉄鋼協会の論文
1957-02-01

リムを超耐熱鋼 LCN-155 で作れる大型複合車盤の製造研究

スポンサーリンク

概要

著者

関連論文

スポンサーリンク