Lab Report: Carbon Steel And Jominy Test

KING FAHD UNIVERSITY OF PETROLEUM & MINERALS

MECHANICAL ENGINEERING DEPARTMENT

ME 217: Material Lab

Student Name Waleed Khalid Jaber

Student ID # 201562570

Section # 06

Experiment No. & Title Carbon Steel and Jominy Test

Instructor Name BILAL TAUQIR

Date 11/DEC/2017

Cover Page 0

Introduction & Objectives 3

Experimental Procedure 3

Results & Discussion 10

Conclusion 4

Total 20

Introduction and objectives

Steel is one of the world’s most commonly used materials. This is simply because it is very versatile and it has many different variations. Different types of steel have different hardness values, these different types of steels can be obtained using different methods. Such as introducing different amounts of carbon into

This shows that the rate of cooling can drastically affect the mechanical properties of the material. For instance, cooling the steel very quickly from a temperature above 727 0C causes the steel to form a structure called martensite. This structure is extremely hard and vey brittle. Furthermore, reheating the specimen to a lower temperature increases the toughness but lowers the hardness.

Understanding how hardness is affected by heat treatment processes is very important, since it will allow us to choose the correct heat treatment method to be used on steel for different applications.

A Jominy test is a test that is performed to see how a certain specimen with a certain amount of carbon in it will react to different rates of cooling. A cylindrical specimen is heated until it completely reaches the austenite phase, and then the bottom of the cylinder is sprayed with a constant jet of water. This causes the bottom to cool very quickly, and as you go up the cylinder, the cooling rate starts to decline. This causes different phases and structures to form on the cylinder. Which enables us to then perform hardness testing on it and see how cooling rates affect the hardness of the

One sample was taken out of the furnace and left to cool in room air temperature, this process is called normalizing. Another sample was quenched by placing it in a water bath quickly after removing it from the furnace. The third sample was placed in a Jominy testing machines where the bottom tip of the cylinder touched the cool water, after which, the samples’ hardness was tested at different points along the cylinder and the hardness was recorded. Heat annealing treatment wasn’t performed simply because it would’ve taken too much time to let the sample cool in the furnace