1 Not all adenomas produce excess T-4, and doctors aren't sure what causes some to begin producing too much hormone. 2  Thyroiditis. 3  Sometimes your thyroid gland can become inflamed for unknown reasons. 4  The inflammation can cause excess thyroid hormone stored in the gland to leak into your bloodstream.
Forged steel is an alloy of carbon and iron that is compressed under extreme pressure to make a very hard and strong substance. It has been used for thousands of years to create all types of materials.
Steel is a superior metal for weapons than bronze or cast iron. But figuring out how to make steel is really, really hard when you don't have modern chemistry or microscopes. It's a process of trial and error and it's mostly error. Steel was not a major factor in armaments until after the Roman period.