Chapter 13, Problem 13.39P

Interpretation Introduction

(a)

Interpretation:

The maximum diameter of bar $\text{1050}$ that will produce a minimum hardness of $\text{ HRC}\text{40}$ should be determined.

Concept introduction:

Hardness is the property of material which provides resistance to permanent deformation such as wear, abrasion, and scratch. It helps in define the characteristics of the material and its function ability according to its requirement.

Jominy test is test used for comparing the hardness of steel. The graph for Joimy distance is shown below:

Answer to Problem 13.39P

The required value of maximum diameter of bar $1050$ that will produce a minimum hardness of $\text{HRC}\text{40}$ is $1.3\text{inch}$.

Explanation of Solution

Given information:

Agitated water is used for quenching of steel.

Minimum hardness of $\text{HRC}\text{40}$ is considered.

Calculation of Jominy thickness using the given data of steel 1050 at HRC 40:

Using the graph of Jominy distance with Rockwell hardness test, drawing the tie lines for determining the value of Jominy thickness:

Thus, the Jominy distance for $1050:\text{HRC }40$ is $\frac{3}{16}\text{of}\text{an}\text{inch}$.

Using Jominy distance for calculating the value of maximum diameter using graph,

Using the Jominy distance of $\frac{3}{16}\text{of}\text{an}\text{inch}$, drawing a line for calculating the maximum diameter.

Maximum diameter of $1050:\text{HRC }40$ is $1.3\text{inch}$.

Interpretation Introduction

(b)

Interpretation:

The maximum diameter of bar $\text{1080}$ that will produce a minimum hardness $\text{ HRC}\text{40}$ should be determined.

Concept introduction:

Hardness is the property of material which provides resistance to permanent deformation such as wear, abrasion, and scratch. It helps in define the characteristics of the material and its function ability according to its requirement.

Jominy test is test used for comparing the hardness of steel. The graph for Joimy distance is shown below:

Answer to Problem 13.39P

The required value of maximum diameter of bar $1080$ that will produce a minimum hardness of $\text{HRC}\text{40}$ is $1.9\text{inch}$.

Explanation of Solution

Calculation of Jominy thickness using the given data of steel 1080 at HRC 40:

Using the graph of Jominy distance with Rockwell hardness test, drawing the tie lines for determining the value of Jominy thickness:

Thus, the Jominy distance for $1080:\text{HRC }40$ is $\frac{10}{16}\text{of}\text{an}\text{inch}$.

Using Jominy distance for calculating the value of maximum diameter using graph,

Using the Jominy distance of $\frac{10}{16}\text{of}\text{an}\text{inch}$, drawing a line for calculating the maximum diameter.

Maximum diameter of $1080:\text{HRC }40$ is $1.9\text{inch}$.

Interpretation Introduction

(c)

Interpretation:

The maximum diameter of bar $4320$ that will produce a minimum hardness $\text{ HRC}\text{40}$ should be determined.

Concept introduction:

Hardness is the property of material which provides resistance to permanent deformation such as wear, abrasion, and scratch. It helps in define the characteristics of the material and its function ability according to its requirement.

Jominy test is test used for comparing the hardness of steel. The graph for Joimy distance is shown below:

Answer to Problem 13.39P

The required value of maximum diameter of bar $4320$ that will produce a minimum hardness of $\text{HRC}\text{40}$ is $1.9\text{inch}$.

Explanation of Solution

Calculation of Jominy thickness using the given data of steel 4320 at HRC 40:

Using the graph of Jominy distance with Rockwell hardness test, drawing the tie lines for determining the value of Jominy thickness:

Thus, the Jominy distance for $4320:\text{HRC }40$ is $\frac{5}{16}\text{of}\text{an}\text{inch}$.

Using Jominy distance for calculating the value of maximum diameter using graph,

Using the Jominy distance of $\frac{5}{16}\text{of}\text{an}\text{inch}$, drawing a line for calculating the maximum diameter.

Maximum diameter of $4320:\text{HRC }40$ is $1.9\text{inch}$.

Interpretation Introduction

(d)

Interpretation:

The maximum diameter of bar $8640$ that will produce a minimum hardness $\text{ HRC}\text{40}$ should be determined.

Concept introduction:

Hardness is the property of material which provides resistance to permanent deformation such as wear, abrasion, and scratch. It helps in define the characteristics of the material and its function ability according to its requirement.

Jominy test is test used for comparing the hardness of steel. The graph for Joimy distance is shown below:

Answer to Problem 13.39P

The required value of maximum diameter of bar $8640$ that will produce a minimum hardness of $\text{HRC}\text{40}$ is greater than $2.5\text{inch}$.

Explanation of Solution

Calculation of Jominy thickness using the given data of steel 8640 at HRC 40:

Using the graph of Jominy distance with Rockwell hardness test, drawing the tie lines for determining the value of Jominy thickness:

Thus, the Jominy distance for $8640:\text{HRC }40$ is $\frac{19}{16}\text{of}\text{an}\text{inch}$.

Using Jominy distance for calculating the value of maximum diameter using graph,

Using the Jominy distance of $\frac{19}{16}\text{of}\text{an}\text{inch}$, drawing a line for calculating the maximum diameter.

Maximum diameter of $8640:\text{HRC }40$ is greater than $2.5\text{inch}$.

Interpretation Introduction

(e)

Interpretation:

The maximum diameter of bar $4340$ that will produce a minimum hardness $\text{ HRC}\text{40}$ should be determined.

Concept introduction:

Hardness is the property of material which provides resistance to permanent deformation such as wear, abrasion, and scratch. It helps in define the characteristics of the material and its function ability according to its requirement.

Jominy test is test used for comparing the hardness of steel. The graph for Joimy distance is shown below:

Answer to Problem 13.39P

The required value of maximum diameter of bar $4340$ that will produce a minimum hardness of $\text{HRC}\text{40}$ is greater than $2.5\text{inch}$.

Explanation of Solution

Calculation of Jominy thickness using the given data of steel 4340 at HRC 40:

Using the graph of Jominy distance with Rockwell hardness test, drawing the tie lines for determining the value of Jominy thickness:

Thus, the Jominy distance for $4340:\text{HRC }40$ is $\frac{20}{16}\text{of}\text{an}\text{inch}$.

Using Jominy distance for calculating the value of maximum diameter using graph,

Using the Jominy distance of $\frac{20}{16}\text{of}\text{an}\text{inch}$, drawing a line for calculating the maximum diameter.

Maximum diameter of $4340:\text{HRC }40$ is greater than $2.5\text{inch}$.