Eye-dropper technique proves effective method of testing steel

✍ Scribed by R.H.O.

• Publisher: Elsevier Science
• Year: 1948
• Tongue: English
• Weight: 73 KB
• Volume: 246
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/0016-0032(48)90868-0

✦ Synopsis

Eye-Dropper Technique Proves Effective Method of Testing Steel.-Science has removed the eye-dropper from the family medicine cabinet and put it to work sampling molten steel at 2700 ° F.

The "eye-dropper," as now used industrially in the G. E. Schenectady Works Laboratory, is a heat-resistant glass tube, about the diameter of a lead pencil and 18 in. long, with a rubber bulb at one end. Liquid steel fresh from the furnace is drawn up into the tube by squeezing the rubber bulb, just as an eye-dropper draws up medicine. The steel hardens into a smooth, homogeneous rod within 5 rain., the glass is cracked from it, and the rod is ready to be checked for quality.

Eye-dropper samples may be prepared for analysis in a few minutes. Older techniques required long hours and involved such laborious operations as cuttMg a block from a hardened steel mass, machining it into a rod, and buffing it to a high polish.

Three men, wearing gloves and goggles, form a highly co-ordinated testing team. In a sequence that must take no more than 60 seconds, the first man removes a puddle from the heart of the furnace with a ladle on the end of a 10-ft. pole. A.second worker skims away the slag forming on the surface as the metal approaches the solidifying point. The third man then steps forward with the "eye-dropper" to suck up a glowing sample.

Cut in two and fitted into sockets before a spectrograph, the sample forms two electrodes of a high-voltage arc. An electric spark jumps between the two, giving off a light which varies with the makeup of the electrodes. By breaking up this light into its component colors with a prism, trained observers are able to judge the quality of any given batch of steel sampled by the "eyedropper." R. H. O.