Charpy Impact Test
Charpy Impact Test Report
Table of Contents
Statement of Intent…………………………………………………………………………………..3
Background……………………………………………………………………………………………….3
Equipment…………………………………………………………………………………………………5
Procedure………………………………………………………………………………………………….6
Data and Analysis………………………………………………………………………………………7
Conclusions……………………………………………………………………………………………….11
Works Cited………………………………………………………………………………………………12
Statement of Intent The purpose of the experiment was to run a Charpy Impact Test and compare the energy absorbed between 4130 steel and A36 hot rolled steel and find the ductile to brittle transition for each.
Background
The Charpy test works by suspending a notched specimen at both ends and then breaking the specimen by a falling pendulum. The energy absorbed, as read on the machine, is the measure of impact strength or notch toughness.(Anderson 124-125) You complete the test multiple times with the same material just at different temperatures. This test is used to find out if a material has a ductile to brittle transition, also known as DTBT, as temperature decreases.(Ductile-Brittle) This test is especially useful for the U.S. Navy. It helps them decide on what material to use to build their vessels so that when they go out into frigid waters the ships will not become brittle and break causing them to sink and lose countless lives.
The DTBT is defined by a sudden and significant drop in the energy absorbed by a metal subjected to impact loading due to decreases in temperature. The graph of this transition looks like the one in Figure 1.
Figure 1 (Anderson 143)
The transition can be observed from the fractured surface of the material. The dull fibrous area is a ductile fracture, while the shiny sandy area is a brittle fracture. In the transition phase, both types of fractures can be seen as shown in the Figure 2.
Figure 2(Anderson 144)
As shown, when the temperature increases, the metal will experience a high percentage of
Table of Contents
Statement of Intent…………………………………………………………………………………..3
Background……………………………………………………………………………………………….3
Equipment…………………………………………………………………………………………………5
Procedure………………………………………………………………………………………………….6
Data and Analysis………………………………………………………………………………………7
Conclusions……………………………………………………………………………………………….11
Works Cited………………………………………………………………………………………………12
Statement of Intent The purpose of the experiment was to run a Charpy Impact Test and compare the energy absorbed between 4130 steel and A36 hot rolled steel and find the ductile to brittle transition for each.
Background
The Charpy test works by suspending a notched specimen at both ends and then breaking the specimen by a falling pendulum. The energy absorbed, as read on the machine, is the measure of impact strength or notch toughness.(Anderson 124-125) You complete the test multiple times with the same material just at different temperatures. This test is used to find out if a material has a ductile to brittle transition, also known as DTBT, as temperature decreases.(Ductile-Brittle) This test is especially useful for the U.S. Navy. It helps them decide on what material to use to build their vessels so that when they go out into frigid waters the ships will not become brittle and break causing them to sink and lose countless lives.
The DTBT is defined by a sudden and significant drop in the energy absorbed by a metal subjected to impact loading due to decreases in temperature. The graph of this transition looks like the one in Figure 1.
Figure 1 (Anderson 143)
The transition can be observed from the fractured surface of the material. The dull fibrous area is a ductile fracture, while the shiny sandy area is a brittle fracture. In the transition phase, both types of fractures can be seen as shown in the Figure 2.
Figure 2(Anderson 144)
As shown, when the temperature increases, the metal will experience a high percentage of
Cited: Anderson, Robert Clark. Inspection of Metals, Volume 2: Destructive Testing. Carnes Publication Services, 1988. Print. “ASTM A36 Mild/Low Carbon Steel.” 30 Oct. 2012. AZoM Editors. “4130 Chrome Moly Steel Properties and Applications.” 30 Oct. 2012. Brockenbrough, Roger L. Properties of Structural Steels and Effects of Steelmaking and Fabrication. 30 Oct. 2012 Norsok Standard. Material Data Sheets for Piping. 1997. Web.