| 摘要 |
<p>1,131,721. Sintered steel strip. SCHLOEMANNA.G. Oct. 8, 1965 [Oct. 22, 1964; Jan. 19, 1965(2); March 17, 1965; April 14, 1965; April 17, 1965], No.42730/65. Heading C7D. Rolled steel section such as strip is produced from steel particles with a grain size of at least 0À2 mm by rolling the particles to full density in one pass at a peripheral roll speed of at least 0À4 metre per second and at a temperature of 600‹C. to below the melting point of the particles. The particles, formed by granulating molten steel or as shavings or iron sponge, are deoxidised by heating in partly burnt town gas or natural gas or hydrogen prior to rolling and are protected from reoxidation during rolling. The preferred rolling speed is 1-1À5 metres per second and it should be at least 2000 times the particle diameter in mms. A continuous process is shown in Fig. 1, the particles passing from hopper 2 into rotary kiln 3 where the particles are reduced and heated to the working temperature of 900‹ -1250‹ C. The heated particles flow into sealed container 6 and from hopper 6a into rolls 9a. A reducing gas such as hydrogen is introduced into container 6 at 13. Figs. 5, 6 and 7 (not shown) show the special construction of the feed hopper and the supply of a protective gas such as argon to prevent reoxidation of the particles. A by pass arrangement may be placed between the rotary kiln and the rolls so as to deflect the flow of particles from the rolls if so desired Figs. 3 and 4 (not shown).</p> |
