Question

A sample of 1095 steel is heated to 1500 degrees Fahrenheit. It is cooled to 500 degrees Fahrenheit in one second. Then, it is held at 500 degrees Fahrenheit for 10 hours. Finally, it is cooled to room temperature in one hour. What is the final structure of the steel?

What is the range of hardness values for the sample of 1095 steel?

Answer 1

1095 STEEL is a very simple high carbon steel that easy to shape by forging so, it is used for making the knife. It contains carbon 0.9- 1.03%( it is a hypereutectoid steel ) and manganese (Mn) 0.3-0.5 % and some amount of sulfur and phosphorous.

When a sample of 1095 steel is heated to 1500⁰ F, it belongs to - austenite phase. when it is rapid cool to 500⁰F in one second it transfers to martensite phase ( brittle structure). when we keep this steel at 500 ⁰F for next 10 hr then as per T-T-T diagram the cooling line just cross the nose of the curve and enter into the pearlite region and when we cool the steel from 500⁰ F to room temperature in 1 hr it will be totally converted to BAINITE STRUCTURE. Bainite is a plate-like structure which consists of CEMENTITE AND DISLOCATION RICH FERRITE.

For determination of the range of hardness values of a sample of 1095 steel, we have to know that with increasing the temperature of a steel it's hardness decrease.

RANGE OF THE HARDNESS VALUE OF 1095 STEEL

TEMPERATURE(⁰ F) ROCKWELL HARDNESS (HRC)   

300 65

400 62-63

500 59-60

600 55-56

650 53-54

This is a TTT diagram which shows the hardness of 1095 steel at various temperature.