Chapter 13, Problem 13.14P

Interpretation Introduction

(a)

Interpretation:

The microstructure present in $1050$ steel heated at $820°C$, quench to $650°C$, and hold for $90s$ and quench to $25°C$ needs to be determined.

Concept Introduction:

Heat treatment is a process used to change the material's physical and chemical properties. Metallurgical is the most frequent applications. Heat treatment is used in the production of many products such as glass. Heat treatment includes heating or cooling to achieve the required outcome, usually at extreme temperatures.

Answer to Problem 13.14P

The microstructure that is present after going through the various processes, is ferrite and pearlite.

Explanation of Solution

  

When $1050$ steel is heated to $820°C$ the steel is present in the austenite form. During the quenching to $650°C$ and hold for $90s$ (seconds), pearlite and ferrite are formed. On further quenching to $25°C$, the only microstructure remaining are ferrite and pearlite. Thus, only ferrite and pearlite remain after going through heating and quenching.

Interpretation Introduction

(b)

Interpretation:

The microstructure present in steel heated at $820°C$, quenching to $450°C$, and hold for $90s$ and quench to $25°C$ needs to be determined.

Concept Introduction:

Heat treatment is a process used to change the material'sphysical and chemical properties. Metallurgical is the most frequent applications. Heat treatment is used in the production of many products such as glass. Heat treatment includes heating or cooling to achieve the required outcome, usually at extreme temperatures.

Answer to Problem 13.14P

Bainite remains as microstructure after going through the heating and quenching process.

Explanation of Solution

  

When $1050$ is heated to $820°C$, the steel is present in the austenite form. During the quenching to $450°C$ and held for $90s$, bainite is formed.On further quenching to $25°C$ bainiteremains a microstructure.

Thus, bainite microstructure remains after going through heating and quenching.

Interpretation Introduction

(c)

Interpretation:

The microstructure present in steel after being heated at $820°C$ and quenched to $25°C$ needs to be determined.

Concept Introduction:

Heat treatment is a process used to change the material's physical and chemical properties. Metallurgical is the most frequent applications. Heat treatment is used in the production of many products such as glass. Heat treatment includes heating or cooling to achieve the required outcome, usually at extreme temperatures.

Answer to Problem 13.14P

Martensite remains as microstructure after heated at $820°C$ and quenched to $25°C$.

Explanation of Solution

  

When $1050$ steel is heated at $820°C$ it is in the form of austenite, after quenching to $25°C$ martensite is obtained.

Interpretation Introduction

(d)

Interpretation:

The microstructure present in $1050$ steel after being heated at $820°C$, quenched to $720°C$, hold for $100s$ and further quenched to $25°C$ needs to be described.

Concept Introduction:

Heat treatment is a process used to change the materials physical and chemical properties. Metallurgical is the most frequent applications. Heat treatment is used in the production of many other products such as glass. Heat treatment includes heating or cooling to achieve the required outcome, usually at extreme temperatures.

Answer to Problem 13.14P

Ferrite and martensite remain as microstructure after heated at $820°C$, quenched to $720°C$, held for $100s$ and quench to $25°C$.

Explanation of Solution

  

When $1050$ steel is heated to $820°C$ it is in the form of austenite. After quenching to $720°C$ and held for $100s$ ferrite is formed while a little austenite remains in the microstructure. After further quenching to $25°C$, the remaining austenite gets transformed into martensite. Thus, only ferrite and martensite remains as microstructure.

Interpretation Introduction

(e)

Interpretation:

The microstructure present in $1050$ steel when heated at $820°C$, quenched to $720°C$, hold for $100s$, quenched to $400°C$ and further hold for $500s$ andquenched to $25°C$ needs to be decribed.

Concept Introduction:

Heat treatment is a process used to change the material's physical and chemical properties. Metallurgical is the most frequent applications. Heat treatment is used in the production of many products such as glass. Heat treatment includes heating or cooling to achieve the required outcome, usually at extreme temperatures.

Answer to Problem 13.14P

Ferrite and bainite remain as microstructure.

Explanation of Solution

  

When the $1050$ steel is heated at $820°C$ it is present in the austenite form. During quenching to $720°C$ and held for $100s$, ferrite is formed, also a little austenite remains in the microstructure.After further quenching to $400°C$ and being held for $500s$, the remaining austenite transforms to bainite. At the last quenching to $25°C$, the microstructure that remain are ferrite and bainite.

Interpretation Introduction

(f)

Interpretation:

The microstructure present in $1050$ steel when heated at $820°C$, quench to $720°C$, and hold for $100s$, quench to $400°C$ and further hold for $10s$, and quench to $25°C$ needs to be decribed.

Concept Introduction:

Heat treatment is a process used to change the material's physical and chemical properties. Metallurgical is the most frequent applications. Heat treatment is used in the production of many products such as glass. Heat treatment includes heating or cooling to achieve the required outcome, usually at extreme temperatures.

Answer to Problem 13.14P

Ferrite, bainite, and martensite remain as microstructure.

Explanation of Solution

  

When $1050$ steel is heated, it is in the austenite form. During the quenching to $720{}^o\text{C}$ and held for 100 s, ferrite is formed but a little austenite remains in a microstructure. On further quenching to $400{}^o\text{C}$ and held for 10 s, some austenite transforms into bainite, but still some of the austenite remains in the solution. After quenching to $25{}^{\circ }C$, the remaining austenite changes to martensite. At last, the microstructure remaining are ferrite, bainite, and martensite.

Interpretation Introduction

(g)

Interpretation:

The microstructure in $1050$ steel when it is heated at $820°C$ quenched to, further heated to $500°C$ and hold for $103s$ then air cool to $25°C$ needs to be decribed.

Concept Introduction:

Heat treatment is a process used to change the material's physical and chemical properties. Metallurgical is the most frequent applications. Heat treatment is used in the production of many products such as glass. Heat treatment includes heating or cooling to achieve the required outcome, usually at extreme temperatures.

Answer to Problem 13.14P

Tempered martensite is the only microstructures that remain in $1050$ steel after heating quenching and air cooling.

Explanation of Solution

  

When $1050$ steel is heated to $820°C$, it is in the form of austenite. The austenite transforms into martensite after quenchingto $25°C$. When it is heated to $500°C$ and held for $103s$, the martensite gets tempered and after it is air-cooled to room temperature, final microstructure which is remaining is tempered martensite.