METALLURGY. 



process of hardening resulted in similar modifi- 

 cationsincrease in breaking load, decrease in 

 elongation, and increase in the resistance to 

 bending and impact at of these modi- 



:is varies notably with the chemical e..m- 

 :lie metal a'nd with the nature of the 



ing bath. A further conclu 

 generally speaking, if a metal is heated to a 

 temperature higl re is a risk 



not being hardened, while if it is heated 

 to a temperature of more than ?50 a or 800 C. 

 there is no longer any great advantage to be 

 gained. The result is regarded as sh 

 the elementary phenomenon of hardening is very 

 simple, and that the only difficulties to b. 

 come are concerned with the equal i. 

 complete transformation of large pieces of ma- 

 terial. 



By a strict observance of the rule that a steel 

 casting should, as far as possible, be of uniform 

 thickness founders have been able to make 

 within the past few years castings 20 feet long 

 by 10 feet wide, which would have previously 

 been considered almost impossible. Vet, while 

 tory large steel castings can be 

 obtained, good small ones are much less easily 

 produced. Mr. II. L. (lantt says that this is be- 

 cause in the necessarily large* meltings of the 

 open-hearth furnaces, where most of this work 

 is done, the metal becomes cooled during tin- 

 many pourings required for the smaller casting. 

 The ditliculty is overcome by the use of a small 

 Beseem <r < on vert, r, " from which we may get 

 : tons of metal as hot as we may wish it. 



> this the fact that we can get from the 

 converter that quantity of metal of any compo- 

 sition we may desire every half hour through- 

 out the day, and we realize the advantage of the 

 Bessemer process for making small and medium 

 weight castings." Among the other advances 

 recently made in casting steel Mr. Gantt men- 

 tions a method for making a casting having one 

 or more faces of a steel much harder than the 

 body of the casting. The process consi 

 lining such faces of the mold as will be adja- 

 cent to the parts of the casting it is desired to 

 harden with a metallic alloy in a crushed or 

 powdered state, capable of being melted and ab- 

 sorbed by the molten steel in contact with it, 

 and of such a nature as to impart to the steel a 

 hard face or a face of such composition as may 

 be readily hardened. If it is desired that the 

 casting have a permanently hard face and be 

 used for stamp shoes, crusher jaws, hammer 

 dies, etc.. ferro-manganese gives the best results. 

 If it in desired to do machine work on the face, 

 and make it extremely hard afterward, fern- 

 >e is most suitable. The fact that it is 

 possible to produce a soft-steel casting having a 

 face that can be hardened without tanking the 

 remainder of the casting to become brittle will 

 make it practicable to use steel castings in place 

 chilled iron in many places with great advan- 



r^ 



ticket steel containing about 3} per* 

 -_kel is now produced, Mr. Henry A. \V 

 ay*, with the same elongation as wrough 

 a tensile strength ful , ,,t. higher than 



ordinary steel, and an elastic limit at least 75 per 

 <*nt. higher. The material possesses great uni- 

 formity, the nickel being evenly distributed 



throughout the ingot, and not liable to 

 tion like other of the ingredients of 

 Its greater strength, ami particularly 

 elastic limit, in 



than ordinary steel. It is the elu-tie li 

 ion in this mat.-n.-.. 



this there is in Illekel Meel a rolisid- 



of ultimate strength, with a large 



The use of nickel steel in ben- 



angles, etc., is likely to lead t 



-iinilar l<> that \\hi- 

 when steel .superseded wrought n 

 obtainable with a 

 inieiits and use in j 

 that nickel steel possesses a in. n 

 \antai:e in being less i-orrodiblr thai. 

 Implication to which 

 is put in armor plate, gun forging-, 

 shafting, Mr. I-'. L. > perry finds a still uj,j, 

 Held open to its use for structural 

 castings, car couplers, car \\ I- 

 small pinions and knuckles, shear kni*. 

 cycle spokes, gears for motors, and all \. 



rk demanding hardness, ton 

 malleability. Plates of iron or steel and 

 when laid together and heated to w< 

 pc rat u re, may be rolled into thin plates 

 continuous nickel surface on both si 

 or steel on one side and nickel < 

 The union of the two metals is n 

 welding, but is of the nature of i-en.- 

 actual alloy being formed to some . 

 the surface of contact. The additional 

 curred by the use of the nickel is reg.v 

 more than made up for by the ad van tag 

 are gained. 



The nickel-steel plates on the new Sj^^l 

 vessels of the United States, being 1 

 the Harvey process, are proof against the 

 steel drill, and it has been found necefl^^l 

 anneal them locally in order to make it ; 

 to insert rivets and bolts in them in l> 

 In the first attempts it proved imp 1 

 confine the effects of the annealing to it 

 spot where the drill was to be applied, or 

 vent their spreading around it. An < 

 application was finally made, and 

 now done satisfactorily. 



The observations of*. I. K 

 of arsenic on steel lead to the com 

 between O'lO and ()!"> it has n.. m 

 on the mechanical properties f,,r st 

 poses; that with 0*20 per cent, sligh; 

 noticed iii an acid open-heart h 

 ing properties of pieces cut across tl, 

 of rolling after they have been tempered. 



cent, the tenacity* is increased. 

 tion is slightly reduced, and t). 

 teriallv reduced : the bending prop* 

 steel are, however, fairly good. V 



amounts to about 1 : 

 is still further increased and the cl< 

 contraction of area are still further 

 while the bemlim: \ 

 per cent, of arsenic the tenant y is iwn--- 

 the elongation and contraction i 



-o tests were made on small bars not as w< 

 worked as larger ones would have 

 effect of quenching the steel when ars. 

 present in large quantities, aft- r h< . 

 heat, was to improve the bending proj>erty. AT 





