Environmentally Assisted Cracking Concerns 

for Cadmium Replacement 

by Scott M. Grendahl 

ARL-TR-3099 December 2003 

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Army Research Laboratory 

Aberdeen Proving Ground, MD 21005-5069 

ARL-TR-3099 December 2003 

Environmentally Assisted Cracking: Concerns 

for Cadmium Replacement 

Scott M. Grendahl 

Weapons and Materials Research Directorate, ARL 

Approved for public release; distribution is unlimited.
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 Environmentally Assisted Cracking: Concerns for Cadmium Replacement

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 181E31 

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 Grendahl, S.M. (ARL) 

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 Weapons and Materials Research Directorate 

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14. ABSTRACT 

Recently, cadmium replacement has become the topic of an Environmental Security Technology Certification Program. 

As a direct result of this program, replacement coating systems will be developed and scrutinized. A fundamental starting 

point for corrosion-resistant coatings development work consists of a target for the overall chemical potential (galvanic 

series) and pH of the coating system and the substrate. This work developed the data necessary to determine the target for 

several high strength steels. Hydrogen is widely recognized as having a detrimental embrittling effect on high strength 

materials, especially high strength steel. Many of these materials show a strong dependence of hydrogen on chemical 

potential and pH. This work focused on determining the effect of hydrogen on the environmentally assisted cracking 

critical stress intensity values (KIEAC) for several common high strength structural steels. Evaluating the effects of 

hydrogen on KIEAC over a range of chemical potential and pH will make the optimum chemical potential and pH evident 

for each material. It then becomes possible for the coating system designers to tailor a prospective coating system around 

those optimum values with the various substrates. If a system were designed at the optimum values for chemical potential 

and pH, the substrate material would be at the most tolerant conditions for resisting detrimental hydrogen effects, 

regardless of the source of the hydrogen.

15. SUBJECT TERMS

 critical stress intensity electrochemical potential environmentally assisted cracking (EAC) high strength steel 

 PH 13-8 Mo steel 4335 steel vacuum arc remelt (VAR) steel 

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19a. NAME OF RESPONSIBLE PERSON

 Scott M. Grendahl 

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iii 

Contents 

List of Figures iv

List of Tables iv

1. Introduction 1

2. Experimental Procedure 2

3. Results 6

4. Discussion 11

5. Conclusions 12

6. References 13 

Distribution List 15 
iv 

List of Figures 

Figure 1. Schematic of the KIEAC fracture specimen.......................................................................4 

Figure 2. Schematic of the KIEAC fracture apparatus. .....................................................................4 

Figure 3. Crack length determination procedure. ...........................................................................5 

Figure 4. KIEAC results for VAR 4340 HRC 52. .............................................................................6 

Figure 5. KIEAC results for VAR 4340 HRC 38. .............................................................................7 

Figure 6. KIEAC results for PH 13-8 molybdenum. .........................................................................8 

Figure 7. KIEAC results for 4335 steel..............................................................................................8 

Figure 8. Fracture morphology zones for VAR 4340 HRC 52 steel. .............................................9 

Figure 9. Fracture morphology zones for VAR 4340 HRC 38 steel. .............................................9 

Figure 10. Fracture morphology zones for PH 13-8 molybdenum steel.......................................10 

Figure 11. Fracture morphology zones for 4335 steel. .................................................................10 

List of Tables 

Table 1. Chemical composition of supplied experimental materials..............................................2 

Table 2. Mechanical properties of supplied experimental materials. .............................................3 

Table 3. KIEAC/KIc ratios for the tested materials..........................................................................11 

Table 4. Maximum and minimum measured KIEAC values for the tested materials. ....................12 
1 

1. Introduction 

Cadmium coatings are currently used in every major land, sea, and air defense system in a wide 

variety of system-critical applications. Cadmium plays an important role in the substrate-coating 

relationship. The functional performance of the coating system contributes to the longevity and 

mechanical performance of any coated component. In the case of high strength steels, the 

functional performance of cadmium coatings as part of the substrate-coating system evolved over 

several decades of in-service use. Because of the wide range of environmental regulation and 

costs associated with the use, handling, and disposal of cadmium-containing components and 

processes, the Government has determined that a replacement must be found. A fundamental 

starting point for the research required to accomplish this task begins with the determination of 

the materials that are common substrates for the cadmium-containing coating systems. 

These materials, most commonly high strength steels, are deleteriously affected by hydrogen 

generated at or near the surface from the natural corrosion process of the environment, 

particularly when they possess yield strengths above 1400 MPa (1). This deleterious effect of 

hydrogen on high strength material by the environment is typically referred to as 

environmentally assisted cracking (EAC). Failures of military grade steels with cadmiumcontaining coating systems have been reported extensively in the literature (2–7). Since all 

substrates reach equilibrium in the environment (in terms of pH and electrochemical potential) 

with their respective coating systems, it would be extremely beneficial to know the optimum pH 

and electrochemical potential where the tolerance of the high strength material to EAC is at the 

maximum level. A coating system could then be designed around those parameters for each 

individual material. If a coating system were designed with no regard for the equilibrium pH and 

electrochemical potential, it is quite possible that the system could fail prematurely, since high 

strength materials demonstrate a strong dependence on these parameters. Although there are a 

number of standard procedures for assessing the susceptibility of high strength steel to hydrogenassisted cracking (9–21), none of these methods address the effect of electrochemical potential 

and pH, both of which are real characteristics of the environment where these steels are used. 

Determination of the optimum pH and electrochemical potential where a material is most 

tolerant to hydrogen can be achieved in several ways. One way is to measure the critical stress 

intensity, KI, at various artificially generated electrochemical potentials and over a range of pH. 

Although artificially created, the resulting data could be referred to as the critical stress intensity 

for environmentally assisted cracking (KIEAC) with the understanding that equilibrium conditions 

in the environment will be established with the coated substrate; these conditions include the 

parameters expressed in equation 1. The equilibrium potential for the hydrogen proton reaction 

in water is as follows: 
2 

2 2

log 2

0.059 0.059 H H H E pH  ρ 

 



 + = − − [1] 

The potential varies as a function of pH and hydrogen pressure. Therefore, the likelihood to 

produce hydrogen gas or monatomic hydrogen increases as electrochemical potential and pH 

decrease. Strong effects of these parameters on the measured critical stress intensity have been 

demonstrated (8). 

2. Experimental Procedure 

It was concluded, based on numerous conversations with the Environmental Security 

Technology Certification Program, that the most frequently used high strength steels in critical 

military applications were vacuum arc re-melted (VAR) 4340 at various strength levels, 

PH1 13-8 molybdenum steel in the H1000 condition, and 4335V steel. The VAR material was 

tested in the Rockwell C hardness (HRC) 38 and HRC 52 conditions. The VAR 4340 had two 

heat treatments: a) an 845° C austenitizing treatment for 30 minutes followed by an oil quench 

and a 340° C, 1-hour temper which yielded a hardness of 52 HRC, and b) an 845° C 

austenitizing treatment for 30 minutes followed by an oil quench and a 470° C temper for 1 hour 

which yielded a hardness of 38 HRC. The supplied chemical composition and mechanical 

properties are presented in tables 1 and 2. 

Table 1. Chemical composition of supplied experimental materials.

Element VAR 4340 PH 13-8 

Molybdenum 

4335 

Carbon 0.42 0.032 0.36 

Manganese 0.77 0.03 0.72 

Silicon 0.28 0.05 0.28 

Phosphorus 0.009 0.007 0.008 

Sulfur 0.002 0.0004 0.009 

Chromium 0.76 12.45 0.75 

Nickel 1.76 8.25 1.83 

Molybdenum 0.23 2.20 0.37 

Cobalt NA 0.02 NA 

Aluminum NA 1.03 NA 

Nitrogen NA 0.0030 NA 

Titanium NA 0.018 NA 

Vanadium NA 0.02 0.20 

Oxygen NA 0.0002 NA 

Iron Remainder Remainder Remainder 

 1

precipitation hardenable 
3 

Table 2. Mechanical properties of supplied experimental materials.

Mechanical 

Property 

VAR 4340 

HRC 38 

VAR 4340 

HRC 52 

PH 13-8 

Molybdenum 

4335 

Yield strength, MPa 1070 1550 1460 1450 

Tensile strength, MPa 1200 1875 1520 1655 

Elongation, percent 16 - 15 10 

Reduction of area, 

percent 

- - 63 - 

Hardness, HRC 38 52 46 - 

Plain strain fracture 

toughness 

105 MPa√m 60 MPa√m 100 MPa√m 100 MPa√m 

This work used pre-cracked charpy impact specimens in an 8- to 10-hour slow strain, constant 

displacement rate (0.005 mm/min), double cantilever beam experiment on an Instron Model 

4301 testing apparatus to determine KIEAC. Schematics of the test specimen and testing 

apparatus are presented in figures 1 and 2, respectively. The test specimens were manufactured 

in accordance with ASTM-E-399 (21). The pre-cracking took place in three separate stages that 

incorporated decreasing loading levels. In the initial pre-cracking stage, the load was maintained 

to keep stress intensity values below 80% of the estimated experimental critical stress intensity, 

and the stress ratio (σmax/σmin) was kept between –1 and +0.1. During the final stage of precracking, the load was reduced so the final value of Kmax was unlikely to exceed 60% of the 

estimated value for KI during experimentation. Additionally, the final value for Kmax/E did not 

exceed 0.0032 m1/2, in which E is Young’s Modulus. Pre-crack length, represented by the 

dimensionless expression of crack length over specimen width (a/W), was maintained near 0.5. 

The calculation for the onset of environmentally assisted cracking, or KIEAC, was derived as 

follows for cantilever bending from the four-point bending expression: 

xf( ) a / W

BW

6M a

K 2

IEAC

IEAC 













 π = [2] 

in which 

() () () () ( ) ( ) 2 3 4 f a /W = 1.122 −1.40 a /W + 7.33 a /W −13.08 a /W +14.00 a /W [3] 

in which 

 MIEAC = the applied moment necessary to induce cracking, 

 B = the specimen thickness, 

 W = the specimen depth, and 

 a = the initial crack length. 
4 

Figure 1. Schematic of the KIEAC fracture specimen. 

Figure 2. Schematic of the KIEAC fracture apparatus. 

SCE 

Reference 

Graphite

Electrode

Electrolyte 

Solution Specimen 

Testing Frame 

Notes: 

1. Tolerances, unless noted. 

Squareness ⊥ perpendicular ± 0.001 TIR 

|| parallel ± 0.001 TIR 

 Decimal .XX ± 0.127 mm 

 .XXX ± 0.0254 mm 

 .XXXX ± 0.0127 mm

1.000 cm

1.000 cm

63 

63

0.0254 cm

45°± 1°

0.800 cm

5.500cm

1.000 cm

250 

2.25 cm

CV 2 Charpy 

Specimen 

0.254 mm

root radius 
5 

For double cantilever bending, the term MIEAC becomes PIEACS, in which PIEAC is the load 

necessary to induce critical cracking and S is the length of the moment arm. This yields the used 

expression for KIEAC. 

xf ( ) a W

BW

P S a K IEAC

IEAC / 6

2

3 













 = π

 [4] 

in which 

 f(a/W) varies between 2.3 and 3.2 for a/W values between 0.45 and 0.55, respectively. 

Overall crack length was determined from optical fractographs of each specimen. The final 

crack length was determined from the average of the summation of length measurements 

perpendicular to the crack front. Computer software digitally analyzed the data. First, the photo 

was digitized, and then the software outlined the edges of the notched and pre-cracked region. 

Next, the software filled the notched and pre-cracked area, and subsequently calculated lengths 

across this filled area. The lengths were then averaged. This method is depicted in figure 3 with 

a step size of 20 shown for clarity. The method used had a step size of 1 for maximum accuracy. 

Figure 3. Crack length determination procedure. 

Experimentation was conducted in a range of electrochemical potentials and pH. Each material 

was subjected to neutral 3.5% sodium chloride (NaCl) solution at four different electrochemical 

potentials: –0.6, –0.8, –1.0, and –1.2 volts saturated calomel electrode (VSCE). Electrochemical 
6 

potential was maintained with the use of an Aeromedical Equipment Laboratory Instruments 

Model 2051 potentiastat and a potassium chloride reference. Tests were conducted in dilute 

sulfuric acid at pH 2, and in dilute sodium hydroxide at pH 11, at both –0.6 and –0.8 VSCE. Open 

circuit experiments were also conducted in neutral 3.5% NaCl. Five specimens were tested for 

each group. 

3. Results 

Figure 4 presents the results from the VAR 4340 steel heat treated to HRC 52. These results 

were obtained in the 3.5% NaCl, in the diluted sulfuric acid, and in the sodium hydroxide 

solutions. This material showed the least dependence on electrochemical potential and on pH of 

all the materials investigated. The measured KIEAC values were greatest (22 MPa√m in the NaCl 

and pH 11 solutions at -0.6 VSCE), while the lowest measured KIEAC values, 16 MPa√m, were 

obtained from the NaCl solution at -1.2 and -1.0 VSCE. The measured open circuit KIEAC value in 

3.5% NaCl was approximately 17.5 MPa√m at the measured open circuit potential of -0.57 VSCE. 

The caustic pH levels slightly increased the measured KIEAC values at -0.8 VSCE, although they 

did not appear to significantly increase them at -0.6 VSCE versus those obtained in 3.5% NaCl 

solution at the same potential. Additionally, the acidic solution generally decreased the 

measured value of KIEAC at both -0.8 and -0.6 VSCE, versus those obtained in 3.5% NaCl solution 

at the same potentials. 

Figure 4. KIEAC results for VAR 4340 HRC 52. 

VAR 4340 Steel – HRC 52
7 

The results obtained from VAR 4340 steel heat treated to HRC 38 are presented in figure 5. The 

3.5% NaCl, pH 2 and pH 11 solutions were used. The material demonstrated a great dependence 

on both potential of hydrogen and on electrochemical potential. The greatest measured KIEAC

value, 90 MPa√m, was obtained at –0.8 VSCE in the pH 11 solution. The lowest measured KIEAC

value, 18 MPa√m, was obtained at –1.2 VSCE in the NaCl solution. The pH 11 solution tended to 

increase the measured KIEAC values considerably at –0.6 VSCE, versus those obtained in 3.5% 

NaCl solution at the same potential. Additionally, the acidic solution decreased the measured 

value of KIEAC significantly at –0.8 VSCE, while the measured KIEAC values remained largely 

unaffected at –0.6 VSCE versus those obtained in 3.5% NaCl solution at the same potentials. The 

measured open circuit KIEAC value in 3.5% NaCl was approximately 65 MPa√m at the measured 

open circuit potential of –0.59 VSCE. 

VAR 4340 Steel – HRC 38 

Figure 5. KIEAC results for VAR 4340 HRC 38. 

The results from the PH 13-8 Mo in the H1000 condition are presented in figure 6. Again, KIEAC

values were obtained from all three solutions. The highest measured KIEAC values were 

78 MPa√m and were obtained from the pH 11 solution at -0.8 VSCE. The lowest measured KIEAC

value, 9 MPa√m, was obtained at -1.2 VSCE in the NaCl solution. The measured open circuit 

potential of -0.76 VSCE yielded a KIEAC value in 3.5% NaCl of 72 MPa√m. Similar to the other 

materials, the pH 11 solution raised the measured KIEAC values while the pH 2 solutions lowered 

the measured values. 
8 

Figure 6. KIEAC results for PH 13-8 molybdenum. 

The 4335 material exhibited the same general trend as the other materials. The results for this 

material are presented in figure 7. The highest measured value for KIEAC, 84 MPa√m, was 

obtained in the pH 11 solution at -0.8 VSCE. The lowest measured value was again at -1.2 VSCE

and was approximately 22 MPa√m in 3.5% NaCl. The measured open circuit KIEAC value was 

67 MPa√m at the measured open circuit potential of -0.59 VSCE. 

Figure 7. KIEAC results for 4335 steel. 
9 

The surfaces of the fractured specimens were characterized for fracture morphology within the 

different regions. Each of the three regions (cyclic fatigue transgranular fracture, hydrogenaffected brittle intergranular or semi-intergranular fracture, and semi-ductile or ductile fracture) 

was observed in the materials investigated. Figures 8 through 11 depict the three zones of 

fracture for VAR 4340 HRC 52, VAR 4340 HRC 38, PH 13-8 molybdenum, and 4335 steel, 

respectively. 

Figure 8. Fracture morphology zones for VAR 4340 HRC 52 steel. 

Figure 9. Fracture morphology zones for VAR 4340 HRC 38 steel. 

A B C 

A B C 
10 

Figure 10. Fracture morphology zones for PH 13-8 molybdenum steel. 

Figure 11. Fracture morphology zones for 4335 steel. 

A B C 

A B C 
11 

4. Discussion 

The materials demonstrated strong dependence with electrochemical potential. Additionally, the 

general trend of the pH 11 solution to increase the measured KIEAC values while the pH 2 

solution decreased the measured values held true for all materials. It appeared that the initial 

relationship governing the dissociation of the hydrogen proton reaction dominated the KIEAC

experimentation. It was interesting to note that the PH 13-8 had a nearly direct relationship with 

potential; as potential decreased, so did the measured KIEAC value. VAR 4340 in the HRC 52 

condition remained largely unaffected by electrochemical potential and pH, probably because of 

the sensitivity of the material to hydrogen and the fact that general corrosion of 4340 in 3.5% 

NaCl was sufficient to introduce enough hydrogen in the solution to deleteriously affect the steel. 

The fracture toughness of the materials decreased dramatically in the presence of excess 

hydrogen. The KIEAC/KIc ratios for the tested materials are presented in table 3. 

Table 3. KIEAC/KIc ratios for the tested materials.

 Material PS KIc (MPa√m) KIEAC (MPa√m) at 

-1.2 VSCE

KIEAC/PS KIc

VAR 4340 HRC 52 60 17 0.28 

VAR 4340 HRC 38 105 17 0.16 

PH 13-8 Mo 100 9 0.09 

4335 100 23 0.22 

Since most of these materials are used in conjunction with sacrificial coatings because of their 

poor corrosion resistance, designers must be careful to account for hydrogen damage when 

attempting to avoid critical flaws. This case is more extreme for PH 13-8 molybdenum, for 

example, since its KIEAC/KIc ratio is 0.09. A designer would be more likely to allow a critical 

flaw in this material, when ignoring hydrogen, than in VAR 4340 HRC 52. The KIEAC values in 

the presence of excess hydrogen are actually very similar. Realistically, this is an exaggeration 

because of the extreme amount of hydrogen at –1.2 VSCE, but the trend can certainly be seen, 

even at other potentials, in the plotted data. The minimum and maximum measured KIEAC data 

are summarized in Table 4. Coating system designers can use these data in their designs. By 

tailoring the coating to push the overall potential of the coated substrate toward -0.8 VSCE and 

toward the basic end of the potential of hydrogen scale, we would have a design that yields the 

most hydrogen-tolerant system possible for each material, although the specific values vary 

slightly from case to case. 
12 

Table 4. Maximum and minimum measured KIEAC values for the tested materials.

Material PS KIc 

(MPa√m) 

Maximum KIEAC (MPa√m), 

Potential and pH at 

Maximum

Minimum KIEAC (MPa√m), Potential 

and pH at Minimum 

VAR 4340 

HRC 52 

60 21.4, -0.6 VSCE, pH 11 16.5, -1.2 VSCE, neutral 3.5% NaCl 

VAR 4340 

HRC 38 

105 91.2, -0.8 VSCE, pH 11 17.4, -1.2 VSCE, neutral 3.5% NaCl 

PH 13-8 Mo 100 78.3, -0.8 VSCE, pH 11 9.1, -1.2 VSCE, neutral 3.5% NaCl 

4335 100 84.2, -0.8 VSCE, pH 11 23.4, -1.2 VSCE, neutral 3.5% NaCl 

5. Conclusions 

The detrimental effect of hydrogen on KIc was characterized over a wide electrochemical 

potential and pH range for the high strength steels investigated in this work. Most of the 

materials demonstrated extreme dependence of KIEAC on both electrochemical potential and 

potential of hydrogen. PH 13-8 molybdenum proved to be the most affected. The KIEAC value 

was lowered to approximately 10% of the known plane strain fracture toughness, KIc, value in 

the presence of hydrogen. The other materials behaved similarly but were not as severe. The 

maximum KIEAC values for the materials investigated in neutral 3.5% NaCl were as follow: 

VAR 4340 HRC 52, 21 MPa√m; VAR 4340 HRC 38, 86 MPa√m; PH 13-8 molybdenum, 

59 MPa√m; and 4335 steel, 75 MPa√m. 
13 

6. References 

1. Bruce, C. Hydrogen Damage; In ASM Handbook; 9th Edition; ASM International: 

Phoenix, AZ, 1992; Vol. 13, p 168. 

2. Champagne, V.K. Jr.; Wechsler, G.; Pepi, M.S.; Bhansali, K.J. Failure Analysis of the 

Apache Mixer Pivot Support; MTL-TR-91-25; Materials Technology Laboratory: 

Watertown, MA, 1991. 

3. Levy, M.; Buckley, P.; Beatty, J.; Brown, R.; Huie, R.; Bhansali, K. Failure Analysis of 

the Main Rotor Retention Nut from the AH-64 Helicopter; MTL-TR-92-39; Materials 

Technology Laboratory: Watertown, MA, 1992. 

4. Krutsan, H.M.; Zdanovs'kyi, V.H.; Karvats'kyi, L.M.; Khoma, M.S. Causes of Damages to 

Fan Blades of the Generator of a Steam Turbine. Materials Science May-Jun 1997, 33(3), 

371-374. 

5. Rinker, J.G.; Hochman, R.F. Hydrogen Embrittlement of 4340 Steel as a Result of 

Corrosion of Porous Electroplated Cadmium. Corrosion 1972, 28(6), 231-238. 

6. Champagne, V.K. Jr.; Ziegler, W.; Pepi, M.S. Failure Analysis of the Main Rotor 

Retention Nut, Letter Report; U.S. Army Research Laboratory: Aberdeen Proving Ground, 

MD, 1999. 

7. Champagne, V.K. Jr.; Pepi, M.S.; Ziegler, W.; Grendahl, S.M. Failure Analysis of the AH64 Input Flange; Letter Report; U.S. Army Research Laboratory: Aberdeen Proving 

Ground, MD, 1999. 

8. Buckley, P.F.; Brown R.; Graves, J.H. Corrosion Behavior of High Strength Steels for 

Aerospace Applications, Metallic Materials for Lightweight Applications. Proceedings of 

the 40th Sagamore Army Materials Conference, Plymouth, MA, pp. 449-464, 30 Aug2 Sept. 1993. 

9. American Society for Testing Materials (ASTM). Standard Practice for Preparation and 

Use of Direct Tension Stress-Corrosion Test Specimens; G49-95; ASTM: Philadelphia, 

PA, 1995. 

10. American Society for Testing Materials (ASTM). Standard Test Method for Measurement 

of Hydrogen Embrittlement in Steel by the Incremental Load Technique; F1624-95; 

ASTM: Philadelphia, PA, 1995. 

11. American Society for Testing Materials (ASTM). Standard Practice for Slow Strain Rate 

Testing to Evaluate the Susceptibility of Metallic Materials to Environmentally Assisted 

Cracking; G129-95; ASTM: Philadelphia, PA, 1995. 
14 

12. American Society for Testing Materials (ASTM). Standard Practice for Making and Using 

C-Ring Stress Corrosion Test Specimens; G38-73; ASTM: Philadelphia, PA, 1995. 

13. American Society for Testing Materials (ASTM). Standard Practice for Making and Using 

U-Bend Stress Corrosion Test Specimens; G30-97; ASTM: Philadelphia, PA, 1997. 

14. American Society for Testing Materials (ASTM). Standard Practice Preparation and Use 

of Bent-Beam Stress Corrosion Test Specimens; G39-99; ASTM: Philadelphia, PA, 1999. 

15. American Society for Testing Materials (ASTM). Standard Test Method for Process 

Control Verification to Prevent Hydrogen Embrittlement in Plated or Coated Fasteners; F 

1940-98; ASTM: Philadelphia, PA, 1998. 

16. American Society for Testing Materials (ASTM). Standard Specification for PreTreatments of Iron or Steel for Reducing Risk of Hydrogen Embrittlement; B 849094; 

ASTM: Philadelphia, PA, 1994. 

17. American Society for Testing Materials (ASTM). Standard Test Method for 

Electrochemical Measurement of Diffusible Hydrogen in Steels (Barnacle Electrode); 

F1113-87; ASTM: Philadelphia, PA, 1994. 

18. American Society for Testing Materials (ASTM). Standard Test Method for Determination 

of the Susceptibility of Metallic Materials to Gaseous Hydrogen Embrittlement; F 1459-93; 

ASTM: Philadelphia, PA, 1998. 

19. American Society for Testing Materials (ASTM). Standard Test Method for Electronic 

Measurement for Hydrogen Embrittlement from Cadmium-Electroplating Processes; 

F326-96; ASTM: Philadelphia, PA, 1996. 

20. American Society for Testing Materials (ASTM). Standard Guide for Post-Coating 

Treatments of Steel for Reducing Risk of Hydrogen Embrittlement; B850-98; ASTM: 

Philadelphia, PA, 1998. 

21. American Society for Testing Materials (ASTM). Standard Test Method for Plane Strain 

Fracture Toughness of Metallic Materials; E-399-97; ASTM: Philadelphia, PA, 1998. 
15 

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