What is t-91?

As an AI language model, I cannot be sure whether you meant T-91 as a specific subject matter or a randomly chosen name. Therefore, here are two possible scenarios that T-91 might refer to:

  1. T-91 Steel: T-91 is a type of steel that has high-temperature strength and corrosion resistance. It is commonly used in the manufacturing of boilers, superheaters, and reheaters in power plants. This steel is a combination of chromium, molybdenum, and vanadium, making it durable and reliable in high-pressure and high-temperature environments.

  2. T-91 Assault Rifle: This is a type of rifle used by the Taiwanese military and is designed to fire the 5.56x45mm NATO cartridge. The T-91 rifle is based on the popular AR-15 platform. It features a short-stroke gas piston system, which reduces recoil while enhancing accuracy and reliability. This rifle is also designed for ease of maintenance and has a modular design for easy customization and upgrade. It is widely regarded as one of the best rifles of its type in the world.