Astm stp 585 1975

For comparative purposes bare copper-bearing steel wire and zinc-coated steel wire and fabricated wire products were included in the testing program... sites in the spring and summer of

AMERICAN SOCIETY FOR TESTING AND MATERIALS

1916 Race Streett Philadelphia, Pa 19103

9 BY AMERICAN SOCIETY FOR TESTING AND MATERIALS 1975 Library of Congress Catalog Card Number: 75-3831

NOTE The Society is not responsible, as a body,

for the statements and opinions advanced in this publication

Printed in Gibbsboro, N.J

April 1975

T A B L E OF C O N T ~ T S

F o r e w o r d

Brief Summary of Results

Acknowledgements

Scope of A-5 and A u t h o r i z a t i o n

The Test Program

The Test Plan

Table 1 - Exposure Sites

Description of Test Specimens

Table 2 - Process Description - Preparation of

Test Wires

Table 3 - Base M e t a l Analyses

Coating Weights - General

Coating Analyses and Photomicrographs

Table 4 - M e c h a n i c a l Properties

Table 5 - Description of A l u m i n u m Wire

Materials and A S T M Specifications

Relationship of A l u m i n u m vs Zinc Coating

The Results

Table 6 - U n f a b r i c a t e d Wire

Table 7 - F a r m F i e l d Fence

Table 8 - B a r b e d Wire

Table 9 - Chain Link Fence

Table i0 - 7 Wire Strand

Table ii - Wire Test A b b r e v i a t i o n & Symbols

F O R E W O R D

Committee A-5 on Corrosion of Iron and Steel was organized

the Committee sponsored its first atmospheric exposure of metallic-

date, there have been a considerable number of test programs involving

wire, sheet and hardware

In June 1959, the Advisory Committee on Corrosion authorized

Committee A-5 on Corrosion of Iron and Steel to conduct atmospheric

corrosion tests of aluminum coated wire and wire products at seven

ASTM sites in the United States (See Map on Next Page) and an eighth

was assumed by Eylands Whitecross Limited

For comparative purposes bare copper-bearing steel wire and

zinc-coated steel wire and fabricated wire products were included in

the testing program

(Continued)

B

KURE BEACHt N.C

(34O00N - Tl'o54'W)

BRAZO$ RIVER FREEPORT, TEX AS

BRIEF SUMMARY OF RESULTS

latitude and 2 ~ 34.5' W longitude

The Newark-Kearny site where the specimens are now exposed has

moving of the test site and specimens was necessitated by a request from

the owner, who needed the area for expanding facilities

The wire and wire products specimens were exposed at the seven

U.S sites in the spring and summer of 1961 and at Warrington, England on

products specimens (field fence, barbed wire, chain link fence and 7 wire strand) were exposed at all eight sites

The range of zinc coatings-hot dipped was 0.36 to 2.81 oz per sq

The hot dipped aluminum-coated specimens ranged from 0.27 to 0.63 oz per sq

ft and the aluminum powder metallurgy clad ranged from 1.76 to 4.54 oz per

sq ft of surface

The initial rust corrosion rates of aluminum coated unfabricated wire varied from 0.032 oz per sq ft per year at Kure Beach 800' lot to

(CIR) at State College shows the lighter weight aluminum coated wires (0.27

to 0.37 osf) with a corrosion rate of 0.035 oz per sq ft per year, whereas the higher weight aluminum coated wires (0.43 to 0.63 osf) averages 0.056 oz

Warrington, England

5

Strengthwise-there have only been 2 specimens of aluminum coated wire tested and both of these were from Warrington The data a r e

insufficient to generalize

The details concerning the test data are included in this

paper by V I Kelley They were approved by Committee A - 5 The

committee is pleased to have this paper appear as an ASTM Special

Technical ~ulletin

A C K N O W L E D G E M E N T S The w r i t e r wishes to acknowledge and extend thanks to the following people who h e l p e d w i t h information or personally encouraged the compilation of this document:

G W Bowdren - Public Service Gas and Electric Co

S K C o b u r n - U S Steel Corp

T O Hodges - Kansas State U n i v e r s i t y

R N Johnson - U S~ Steel Corp

V P Pearson - Inland Steel Co

Laury Peters - B e t h l e h e m Steel Corp

E E Ramn - Ohio E d i s o n Co - Chnm of A-5

J H R i g o - U S Steel Corp

Bernard Ryan - Eylands - Whitecross, Limited

C E Shoemaker - Bethlehem Steel Corp

G J Tyler - State of N.J., Dept of Environmental Protection

ATMOSPHERIC CORROSION INVESTIGATION OF

A L U M ~ C O A T E D ~ ZINC-COATED AND COPPER

W m E A m WI E mOD CTS

The scope of Committee A-5 on Corrosion of Iron and Steel is

quoted as "The collection of engineering information relating to the

serviceability of both bare and metallic coated iron and steel products when subject to corrosion and the formulation of methods of tests and

responsible for the atmospheric corrosion of wire and wire products,

be they bare or metallic coated

With the June 1959 authorization from the Advisory Committee

on Corrosion, Subcommitee A05.15, Wire Tests, organized a task group

composed of the following:

E G Baker, Steel Co of Canada

B A Beery, Page Steel and Wire

W W Bradley, Bell Telephone Labs, Inc

R S Dalrymple, Reynolds Metal Co

O B Ellis, Armco Steel Corp

E T Englehart, Aluminum Co of America

P M Emmons, R E A

H H Hormann, Consolidated Edison of N Y

J B Horton, Bethlehem Steel Co

R B Koontz, National Standards Co

J B Kopec, Keystone Steel and Wire Co

T A Lowe, Kaiser Aluminum & Chemical Corp

J F Murphy, Olin Mathieson Chemical Corp

(Continued)

F M Reinhart, U S Naval Eng Lab

Jane H Rigo, U S Steel Corp

T A Schneider, J A Roebling's Sons Divn

C W.Straitor, Detroit Edison Co

C E Topping, Consumers Power Co

L C Whitney, Copperweld Steel Co

1Retired in 1972 after 38 years with American Steel and Wire, Cleveland, Ohio and the U S Steel Corp Pittsburgh, Pa in various metallurgical positions

Seven producers contributed the aluminum-coated steel wire

Bethlehem Steel Co., Copperweld Steel Co., Keystone Steel and Wire Co.,

National Standards Co., Page Steel and Wire Division, J A Roebling's

coated steel wires were also provided for comparative purposes

Southern Electrical Co., Division of Olin M~thieson Chemical Corp.,

contributed to the program in the stranding of the steel-reinforced

fittings used in the test installations of high-strength strand and

steel-reinforced aluminum conductors

chain-link fencing, field fence, high-strength steel wire strand, and

referred to as "7-wire strand" in this document The relative corrosion

resistance of the various test items in the several atmospheres will

be established by visual inspection of the unfabricated and fabricated

wire items and by periodic determination of percentile loss in breaking

strength of the O.148-in.and 0.099-in unfabricated wires

THE TEST PROGRAM:

Aluminum coated unfabricated wire is exposed in twenty 39-in

of test wires are being made to determine loss in breaking strength

(Continued)

The control wires are copper-bearing steel and zinc-coated

steels which are 0.148-in in diameter The aluminum-coated test wires

are 0.148 and 0.099 in in diameter

Test length of the fabricated wire products is i0 ft Whenever

the case of field fence and high-strength steel strand, however, two

styles are involved due to the ready availability of the finish desired

in that particular style Two styles of steel-reinforced aluminum conductors are also exposed These styles are designated as conventional and

compacted

ii

THE TEST PLAN:

1 Unfabricated Wires - Number of replicates = 20, test

length = 39 in (990.6 Em) evaluation by visual observation and loss

in breaking strength

(a) Copper-bearing steel, zinc-coated steel (hot-dipped and electro-deposited steel), aluminum-coated steel (hot-dipped and

powder techniques ), O 148 in diameter

(b) Aluminum-coated steel (hot-dipped and powder techniques), all 0.099 in diameter

2 Fabricated Wire Products - Number of replicates = l,

test length = lO ft., evaluation by visual observation

(a) Barbed Wire - Zinc-coated and aluminum-coated steel,

No 1289 4 point

48 in 9 gage, 2 in mesh, barbed top, knuckled bottom

(c) Field Fence - Zinc coated steel (939-6-9), and zinc- coated steel and aluminum-coated steel (939-6-11)

(d) High-Strength Strand - Zinc-coated steel and al,~m~num- coated steel (3/8 in., 7 wire, 0.120 in.), and aluminum-coated steel

(5/16 in., 7 wire, 0.104 in.)

(e) Steel Reinforced Aluminum Conductors - Zinc-coated and aluminum-coated core wire, Am Wire Gage No 4, seven aluminum

strands (0.0772 in.), one steel (0.1029 in.), conventional, compacted

1See Commercial Standard CS 246-62

(top) Unfabricated wire (center) Strand (7 wire) (bottom) Chain-link and farm-field fence Fig 1 - Al~ninum-Coated Steel Wire, Stranaand Chain-Link

and Field Fence Erected at the Test Sites

Figure I, (top, center and bottom) depicts the manner in which

the unfabricated wire and fabricated wire products are exposed at the

taken to eliminate opportunity for dissimilar metal contact

In Fig 1 (top) the unfabricated test wires are racked in

groups of lO on the standard ASTM pipestand by insertion into predrilled

l~-in, diameter aluminum rounds Prior to insertion into the aluminum

rounds both ends of the wire were dipped in an adhesive, EC 1099

(product of Minnesota Mining and Manufacturing Co ) The aluminum

rounds are installed at center-to-center distance of approximately

at 2-in centers

Figure 1 (center) shows the exposure test setup for the

high strength steel strands and the steel reinforced aluminum conductors

strands and conductors are outfitted at either end of the test

lengths with galvanized or aluminum dead ends, depending upon the

contact metal involved

Field fence and chain link fencing are erected on suitably

specimens are also shown mounted on appropriately finished cross

arms, the aluminum in contact with al,~m~num-coated steel and the

samples were installed by professional erectors, they are tensioned to

the degree normally encountered in service

(cont' d)

Table I lists the exposure sites and assigned site numbers, for future

reference, together with exposure dates for the fabricated and

unfabricated aluminum coated wire and wire pro@ucts The type of

atmosphere at each location is classified in accordance with that set

forth in the 1958 Report of the Advisory Committee on Corrosion The

three major types are industrial, marine and rural

Marine Beach Exposure F~rine

East Coast Rural

Industrial

N~rine West Coast Rural

Exposure Date July 17, 1961

Fabricated

Fabricated & Unfabricated Fabricated

Fabricated & Unfabricated Fabricated

Fabricated & Unfabricated Fabricated & Unfabricated

a Specimens moved to Kearny N.J on July 2 - 1970

State College, Pa.:

This rural site was established in 1925 and is located one

are mounted 30 deg from the horizontal and face SE at an azimuth of

147 deg

Newark, N.J - Newark-Kearny N.J.:

This severe industrial test site was established in 1956 to

an angle of 30 deg from the horizontal and face the SSW at an azimuth

were taken to a new test site known as Newark-Kearny, N.J on the

grounds of Kearny Generation Station at Public Service Electric & Gas

Company

Point Reyes, Calif.:

Point Reyes test site was established in 1950 and is located

1930 ft from the Pacific Ocean behind low hills covered with salt

atmosphere here is characterized by salt spray and condensation exposure

due to westerly winds and dense fogs which keep the specimens moist

frequent heavy fogs at night

Kure Beach, N,C.:

The two exposure sites at Kure Beach are under the direction

of the International Nickel Co and are located on the Cape Fear

approximately 800 ft and the other approximately 80 ft from the Atlantic

Ocean The specimens are mounted 30 deg from the horizontal and face

site, the specimens parallel the beach at an azimuth of llO deg The

80-ft site is characterized by sea water spray falling directly on

the test specimens

Freeport, Tex.: (Brazos River)

In 1952 a test site was established on the Brazos River

at 30 deg from the horizontal and face Southeast (azimuth of 144 deg)

The climate in this area is noted for its consistently high humidity

The daytime relative humidity varies between 85 and 93 per cent in

humidity is almost lO0 per cent all year with frequent heavy dews

Manhattan, Kansas:

This rural site is located in an agricultural area with

rain fall is 33.52 inches

Warrington, England:

This industrial site is located on the Recreation grounds

at Rylands-Whitecross Ltd at am elevation of 28 feet above sea level

The prevaling wind is South Westerly blowing from the town over the site

a diversified industry which includes wire production, light and

heavy engineering, hot rolled steel products, board and paper mills,

figures

The following information was provided by each manufacturer for

unfabricated and fabricated wire products which each supplied:

General description of the coating process

Chemical analysis of the base metal and metallic coating

Weight of metallic coating

Mechanical properties of the unfabricated wires

Minimum and maximum coating thicknesses as measured micro-

scopically

(f.) Cross-sectionalphotGmicrograph to illustrate structure of

coating only

Most of the descriptive information which was supplied by the

several manufacturers was accepted without rechecking by disinterested

excepted These values were rechecked, and any discrepancies were

resolved

General descriptions of the processes whereby the test wires were

prepared are summarized in Table 2 According to these descriptions

the zlnc-coated steel wires were processed by conventional hot or

electrolytic methods Aluminum-coated steel wires prepared by pro-

cesses l, 2, 4, and 5 were coated by passage through a molten bath

of aluminum or an aluminum-silicon alloy Except for two processes,

1 and 6, the steel wires were chemically fluxed prior to passage through

lurgical technique

(Continued)

19

TABLE 2-PROCESS DESCRIPTION-PREPARATION OF TEST WIRES

Cleaned steel wire coated

in a molten bath of zinc Cleaned steel wire electro- plated in a zinc sulfate bath using insoluble anodes

Cleaned steel wire immersed in aqueous flux solution, dried, dipped in silicon-bearing aluminum bath

Powdered aluminum is applied

to a steel core to produce a composite rod which is sub-

s e q u e n t l y c o l d drawn to size

20

Straight-line, hot-dip method

Prefluxed in aqueous solution

of fluoride salt and dipped

in molten aluminum bath

Continuous fluxless hot-dip process

Heavy coating applied by patented process

*Specimens manufactured by process ~ were dropped from the program after

5 years because the manufacturer informed that the wire was no longer

com~nercially available from Process No 4

21

Table 3 reports the chemical analyses of the base metal

for all test specimens, unfabricated and fabricated A review of

these steel analyses shows the carbon content of the base metal for

aluminum coating in a molten bath to be significantlyhigher than for

cQmparable zinc-coated wire Starting with a higher carbon content

for the aluminum-coated steel wire compensates for the greater reduction

in tensile strength which is caused by a higher operating temperature

for an aluminum bath compared to a molten zinc bath The operating

temperature for an a ~ , m ~ n u m b a t h ranges f ~ o m l 2 0 0 to I300F

(649-704C),whereas the operating temperature of a zinc bath varies

f r o m 8 0 0 to 900F (427-482C)

Low, medium, and high carbon steel analyses are represented

among the unfabricatedwires A i m ~ n u m C o n d u c t o r Steel Reinforced

(ACSR) core wires and high strength steel strand are high carbon

products, while barbed wire and field fence are essentially low

carbon metallic coated items Base metal analyses classifies the

zinc-coated chain link fencings as a steel product of lower carbon

content than the aluminum-coated steel chain link fencing The

latter utilized steels of medium carbon content

TA3LE 3 - BASE METAL ANALYSIS OF UN

Specimen Coating Carbon

Per Cent

~anga- nese Per Cent

~BRICATED AND FABRICATED WIRES Phosphorus Sulfur Silicon Per Cent Per Cent Per Cent

9 GAGE (0.i~8 IN ) UNFABRICATED TEST WIRE

Copper Per Cent

0.34 O.5O o.44 o.34

O 010

O 010 o.o13

0 012

O 026 0.021

o.o33

0.01 0.16 O.O1 O.O1

0.23 0.03 0.14 O.09

0 2 2

0.26 0.25

o.45

o 75 o.41 o.81

0.82

o 48 o.91 o.51 o.44

0.014 0.o15

o.o13

0.026

o.o42 o.o19 0.046

O.027

0.01 0.22 O.lO3 0.21 0.23

0.007

0o01 0.023 o.19

O I0

o.14

0.28 0.02 0.03

o.41 0.49 0.41

0.58

0.27

o.9o

0.010 0.012

0.0o6

0.012 0.034 o.o13

O 027 0.025

0.O10 0.22

0.82 o.8o

0.73

O 012 0.021 0.015

O O32

o.o34 o.o23

0.14 0.19

o.15 o.28

o 132

0.19

O 14

O 02 O.11 trace

@ ,

0.I0

23

Silicon Per Cent

Copper Per Cent

0.38 0.40 O.4O 0.49

O 58

0.012

0 010 0.010 0.012 0.012

9 GAGE - 2 IN CHAIN LINK FABRIC

O 021

0.025 o.026 0.025 o.o31

O 16 0.16 0.01

0.005

o oo5

0.03 O.O3 0.03

No 24 line (9 ga)

No 24 line (ii ga)

No 24 stay (II ga)

No 25 line (9 ga)

No 25 stay (9 ga)

No 26 line (9 ga)

No 26 line (II ga)

No 26 stay (ii ga)

O i0

0.08 0.14

0.17

o.23 0.29 0.23

0.II 0.09 0.08

O ii

O II

0.21 0 21 0.07

0.59 O.38 0.38 0.41 O.53 0.81 O.48

FIELD FENCE 0.43 0.44 0.39

0.34 O.37

0.86 0.83 o.45

0.015

o.o13

o.o13 0.013

o.oo8

O.Oll 0.013

0.011 0.010 0.015

o.015 o.o14

O 013 0.012

O 010

0.037 0.028

O 026 0.027 0.025 0.030 o.o42

0.13 0.18 O.O1

0.02

0 ~ 0.22 o.oo7

0.08 O.O3 O.O6

0.03

o.o8 o.o3

I e I

o 032 0.024 o.o15

0.01 0.01 0.01

0.03 0.03

The reported coating weights can be tabulated as shown below

to indicate the range in coating weights observed for the electrolytic

and hot-dip zinc coatings and for the two types of aluminum coatings

Specimen

Unfabricated:

9 gage

Zinc oz per sq ft Hot-Dipped

0.50

Electroplated

0.99,2.84

Aluminum oz per sq ft Hot-Dipped

(light wt) 0.27 (heavy wt) 0.48 to 0.6 3

Powder Metallurgy

It is apparent that heavier coatings of zinc were deposited

dep6sited by passage through a molten bath were substantially lighter

than those coating weights deposited by techniques involving powder

0.63 oz per sq ft compared to 1.76 to 4.54 oz per sq ft for the

other type aluminum coating

The weights and analyses of the coating metals as well as

minimum and maximum coating thicknesses are recorded in Figures 2 through

7 Also included for each item is a photomicrograph of a cross-

sectional area illustrating the structure of the metallic coating

Figure 2

(Fig 2 Continued)

Figure 2

(Fig 2 Continued)

O 50

o.99 2.84

o 52 o.54 0.27

2.44

o.48 o.51

0.27

Coating Analysis, per cent

Iron

i0 trace

trace 4.1o 2.8o

22.31

o.o84

2.52 1.50

1.3o

0.54 1.58

4.42

o.65

0.96

0.8o 8.80

2.3o

ll.5 3.06 2.59 2.36

a

b

Plain copper-bearing steel; 9 ga (O.14~unfabricated wire No photomicrograph

9 gage (0.148 i n ) u n f a b r i c a t e d test wire

(All photomicrographsmagnified 500 X except as noted) Fig 2-Coating Characteristics of Unfabricated and Fabricated Wire

29

Figure 3

(Fig 3 Continued)

(Fig 3 Continued)

Figure 3

(Fig 3 ContinuedB

31

AI

Weight, oz psf

0.~8 0.63 0.29 0.43

Zn A1

0.21 0.37 1.76

3.36 0.87

20.25 1.29

0.080 0.47 trace

0.o80

0.93

4.71

o.0o6 9 0.69

1.46 6.2

m a x

3.70

4.8o 2.24

2.60

2.70 2.60 8.7 15.3

l 58 lO.3

a

b

C

9 gage (0.148 in ) unfabricated test wire

12 89 gage (0.099 in ) unf~bricated test wire

ACSR core wire

(All photomicrographs magnified 500 X except as noted) Fig 3 - Coating Characteristics of Unfabricated and Fabricated Wire

I 77

O Z

Coating Analysis, per cent

Silicon

O 70 4.0 4.93 3.91

2.92 2.91 4.71 @

Thickness, mils min

Iron

4.20 1.0 0.49 8,59

15 9.2 1.34 1.24 1.29 4.25

0.91 0.28 1.O 0.50

O 30 1.01 0.60 1.73

i 02 0.63

max

2.84 2.16 3.9 2.60 o.81 2.95 2.41 2.60 2.60 1.96

a ACSR core wire

c 9 gage - 2 in chain link fence

(All photomicrographs magnified 500 X except as noted) Fig 4 - Coating Characteristics of Unfabricated and Fabricated Wire