Evening star., 1928-03-18
NICKEL PROVES AID
IN HARDEN MING OF IRON
Addition to Metal Eliminates Free
Carbide Spots and Increases
Wear.

Cast iron Is an engineering material
that possesses multitude OF COM
rnendablc properties II Is low In cost.
easy TO cast and readily nnachined
These properties have been the primary
considerations in its selection for use
In many parts according to paper
presented by Thomas II Wickenden Of
the International Nickel Co. at the re-
cent annual meeting Of the Society Of
AutomotiYe Engineers In Detroit Its
ability 10 resist certain types OF wear
has been recognized; but the character.
isticS Of an iron excelling In its re-
sistance 10 wear constitute a subject Of
much discussion among metallurgists
ana engineers and their opinions are
widely divergent. ANY improvement IN
the wearing property OF cast iron Is
heartily welcomed by the engineering
profession. but improvements in this
property must not seriously interfere
WITH It's other primary properties
Numerous examples have been cited
In which a soft iron has shown better
wearing properties than haFo iron un-
der certain conditions. This fact may
be regarded as real news item, for the
opDoz!n is the usual occurrence and
does not cause unusual comment, From
this the conclusion may be deduced
2 true index of the durability of caht
iron but must be considered IN con-
junction with other characteristics-
When carbide spots that are present
constitute only q small percentage oI
The total area. a condition eziAts 0i ia
few spots III hard material embedded IN
q softer material number Of studies
on the worn surfaces of irons contain
Ing tree carbide or phoSpho"carblde
spots have shown that the softer mate
rial wears away, leaving the hard spots
standing 0it In relief on the surface, 4
condition that would result In fspin
wear of the opposing material Besids sa
being hard. the material in these spots
Is also brittle snd II easily broken LOOSE
IL then becomes an abrasive between
the t@1 rubbing surfaces and results IN
scoring marks Prom this the concIu"
sion ran b. drawn that the sn1alie 4
possible amount Of excess phGspDidf
snd carbide content lS desirable. not
only ~ MAKE The iron easily machin-
8 biz but 10 assure gpod wearing prop
critics
Observation ~ the life III great va
slety of cast-iTon parLs shows mat
when increased hardness Is secured
With freedom from free carDides, The
wearing properties III an iron improve
~ ftlf Dsf rI1eAS Increases. also. mat bn
iron containing appfecisbIe amounts d
nickel tAkss Il higher IusLef when poi
ished than HoeK pisln iron, faci
that undoubtedly aids IN Us resistance
~ wear
VaTlDus expedlenls have been used hi
the foundry W produce the most dfstr
able structure. blIt probably the great
e5t progress fss been made recently b5
he intelligent addition ~ nickel and
chromium 10 Gssl iron The effect OI
adding nickel IN Increasing quantities II
raEt iron ik unique It's addition vii
prevent or eliminate free carbide spots
~ white iron. while st the same lime
IL ~l!I iaHrease the hardness III the gray
Dpfiipn III the iron Que IN the formation
~ s9fbibe instead ~ peafltf The ri
GIiion 0f chromium III increasing
! quantities tends 10 increase the amount
~ fpnlblned carbon IN the finished
casting ami If lhf chromium Is nhed in
| excfks, II VII pt0nuff sTssa ~ free car
/ bids. By using byin constituents 10
gFthff IN ihe proper proportions, Doih
siements ere msdf mlfIsnlore effective