Making steel brittle | Designing an experiment to show for students in history class
Hey all, I'm new to this sub! Looking for some guidance, since I started researching the topic and it's a bit confusing. I work in engineering education and this semester our students are taking a course called "6 inventions that changed the world." Among those inventions is steel, as a material, how it influenced the civilization and how incredibly important it has been since.
Our students are engineers so even this history class is supposed to include science/engineering basics for them to learn. Me and my team really wanted to make a cool demonstration for them and came up with the following experiment: taking a steel rod and heating it with a blowtorch (?) until it's glowing hot, then dipping in water. As far as I understand, it must become brittle if left without further heat treatment. We break it it half to demonstrate how brittle it's become and then repeat the procedure but after cooling in water we heat it again and cool slowly, in sand for example, and then try to break it again to reveal that it is much more ductile now.
I would like to get some feedback from people who have experience with this. I'm also not entirely sure it will work the way I described, so I would appreciate critique. Thanks a bunch everyone!