What material is MIG -25 fighter? Why is it called "flying stainless steel"?

Mikoyan MIG -25 is a high-altitude and high-speed interceptor fighter developed by the Mikhail Design Bureau of the Soviet Union in the late 1960s, and it is the first fighter with a maximum flight speed exceeding Mach 3 in the world. Then why is he also called? Feitian stainless steel And then what?

Do you believe in the simple and rude fighting nation? Trying to work miracles? I believe that design is better than material, even a lump of iron can fly as long as the power is enough. What are the original words of the Mikhail design bureau of the fighting nation? As long as there is a strong engine, even if you are 85 bricks, I will push you into the sky. She is an orange that pierces the sky. She is the sword of Damocles that once hung over westerners. She approached SR-7 1 at high speed on the radar screen? Ufo？ . Titanium alloy can't be used, and aluminum alloy is useless. What should I do? The Soviet Union directly made MIG -25 from stainless steel. Do you know how much this thing weighs? The lighter the material of the plane, the better. However, the fighting nation did not take the usual road, but simply used a large piece of iron, causing a high-altitude high-speed flight that broke through Mach 3. MiG -25 adopts a large number of stainless steel structures, and its design emphasizes high-altitude and high-speed performance. If it encounters in the air, F5 can't even eat the tail gas of MIG -25. The top speed of Mach 3.2 has brought a problem to the western world. An American engineer said: It seems that our missiles are not as fast as him? . On the battlefield in the Middle East, Israel tried to launch missiles to pursue MIG -25, but to our great shock, the speed of this MIG -25 exceeded Mach 3.2! Didn't even catch the missile!

There is a joke that goes like this:

Khrushchev inspected the Mikoyan Design Bureau. Seeing this plane, I asked: This plane uses so much steel and is so heavy. How does it avoid missiles? ?

The designer immediately lifted the cockpit cover: Dear Comrade Khrushchev, you don't have to worry at all. This just reflects the exquisiteness of our design. You see, we designed a throttle valve here. ?