OBSERVATIONS ON THE CORROSION OF STEEL IN WATER. 



69 



tooth brush, drying and weighing, 

 expressed as loss of weight. 



Table I. 



Corrosion is then 



Steel 



Steel with platinum 



Steel 



Steel with platinum 



Weight at Start. 



64-563 

 64-619 

 65-371 

 63-382 



Loss of Weight 

 after 17 days. 



0-141 



0-185 



Loss of Weight 

 after 35 days. 



0-258 

 0-326 

 0-273 

 0-303 



(2) Influence of Composition of Steel on Corrosion.— 



Having in our possession slowly cooled steels of composition 

 varying between 0*1°/° carbon and If carbon content, we 

 exposed these to the corrosive influence of a water con- 

 taining bicarbonate of soda, magnesium sulphate and sodium 

 chloride. The results were somewhat irregular, so that 

 few exact conclusions can be drawn regarding the influence 

 of composition on the corrodibility. It is however very 

 noticeable that (1) the initial rate of corrosion is very 

 different from the rate which sets in after a few weeks. 

 (2) a steel containing *9 or If carbon corrodes less in the 

 water used than a steel containing smaller percentages of 

 carbon. 



Table II. 

 Steeh of varying composition exposed to the action of corrosive water 

 containing the following : — Sodium bicarbonate 2 64, magnesium sulphate 

 0*113, sodium chloride 01 66 grams per litre. Surface exposed in 

 each case 390 sq. mm., weight equal 4 grams. 



Percentage of Carbon. 



Loss of Weight after 

 5 weeks. 



Total loss after 6 months. 



0-18 



0-0153 



0-0408 



0-23 



0-0168 



00288 



0-40 



0-0144 



0-0296 



0-62 



0-0118 



0-0170 



0-80 



0-0120 



00178 



0-90 



0-0115 



00164 



118 



0-0141 



00184 



The amounts of Si, P, Mn, S, in these steels were almost identical. 



