Question

1- Abrasive wear is most common in situations in which:

a. Hard particles are caught between two contact surfaces
b. the hardness of one material is much higher than the other
c. Neither A or B
d. Both A and B

2- What material property is critical to predicting wear behavior?

a. buckling resistance
b. tensile strength
c. modulus
d. hardness

3-What is the general cause of corrosion of low carbon steel?

a. Stray electric currents (very small)
b. Using two-dissimilar metals together
c. Being in the presence of moisture or water
d. All the above

Answer 1

Answer 1. Option D. Both A and B.

Abrasive wear mainly occurs because of these two reasons:

1. Three-body abrasion: In this type of Abrasive wear, very hard foreign particles get either trapped in between the two sliding surface or are embedded in one of the materials, as a result, either abrades the softer surface or both of them.

2. Two-body abrasion: In this type of Abrasive wear one of the materials is harder than the other one, as a result, abrades the softer material.

Answer 2. Option D. Hardness.

Hardness is inversely proportional to Wear Volume. Lesser the Wear Volume higher the Hardness and vice versa.

Answer 3. Option C. Being in the presence of moisture or water (General cause).

Stray electric currents do have an impact on corrosion of low carbon steel (DC = more impact; AC = less impact), however, not going to be a general cause. Two dissimilar metals do have an impact however, they also tend to increase the resistance towards corrosion of low carbon steels so, not going to be a general cause of corrosion on low carbon steel so, it's either option C (general cause) or D (All of the above).