Hard Chrome Plating Training Course

Table of Contents

Section 5 Quiz

1. A plated part has defects. If you replate the part in a different tank using the same procedures and it plates successfully, what are the likely causes of the original defects (check all that apply)?

a. Plater forgot to reverse etch the part
b. Poor fixture design
c. Rectifier or chemistry issues
d. Incorrect bath temperature

2. You are given a part with 200 in2 of surface area to chrome plate. The bath temperature is 140°F. What amperage setting will optimize brightness?

a. 610 amps
b. 740 amps
c. 860 amps
d. 1,040 amps

3. You are experiencing insufficient chrome thickness in low current density areas for a particular part. What potential actions may improve this situation? (Check all that apply.)

a. Redesign the anode to better conform to the part
b. Increase the catalyst (sulfate) concentration
c. Increase the bath temperature
d. Lower the bath temperature

4. Look at the part below. What problems do you notice?

What potential actions may improve the plating of this part? (check all that apply)?

a. Pumice scrub the part before plating
b. Increase the chromium-to-catalyst ratio
c. Increase current density
d. Correct the duration of the reverse etch
e. Reduce current density
f. Lower the bath temperature
g. Alter masking procedures

5. Excessive treeing is occurring at the edge of a part. What potential actions may improve this situation? (check all that apply)?

a. Increase the chromium-to-catalyst ratio
b. Mask the part using a lead tape robber
c. Fabricate a PVC collar for masking the part
d. Improve pre-plate cleaning techniques

6. Roughness occurred over the entire plated surface of a piston. What potential actions may improve this situation? (check all that apply)?

a. Increase the current density
b. Increase air agitation in the plating bath
c. Filter the bath
d. Visit the grinder

7. Small pits occurred on isolated portions of a plated shaft. What potential actions may improve this situation? (check all that apply)?

a. Increase the bath temperature
b. Strip the part and look for surface defects
c. Increase current density
d. Change the duration of the reverse etch

8. You checked your old plating bath using a specific gravity hydrometer (Baumé stick). The reading was 21.5 °Be. How much chromic acid is in the bath?

a. 23.0 oz/gal
b. 29.0 oz/gal
c. 33.3 oz/gal
d. <33.3 oz/gal

9. You are experiencing adhesion problems with a 1020 steel piston. You are using a conforming anode and reverse etching for 30 sec. What potential actions may improve this situation? (check all that apply)

a. Increase current density during the plating cycle
b. Improve cleaning techniques
c. Lower the bath temperature
d. Increase the reverse etch time

10. You are plating the outside diameter of a 3 ft. long, 6 in. diameter piston using stick anodes. You are achieving a plating rate of 0.0003 in. thick per hour. How can you increase the plating rate?

a. Lower the chromium to catalyst ratio
b. Raise the bath temperature
c. Increase current density
d. Move the stick anodes closer to the piston

11. Look at the small pin shown below. What is the most likely cause of this problem?

a. Low chromium to sulfate ratio.
b. Excessively high bath temperature.
c. Interuption of current during plating cycle.
d. Poor masking job.

Continue to Section 6



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