Advantages Of Using Stainless Steel For Musk Super Heavy Rocket
Dec 08, 2022
According to the Los Angeles Times, at 9:00 a.m. local time on July 20, Jeff Bezos, the founder of Blue Origin, and his brother Mark Bezos and other four pilots took the "New Shepherd" aircraft from the launch site in western Texas, the United States, and flew to the Earth sub orbit about 105 kilometers from the ground. They successfully returned and landed.
As early as Monday local time, Musk's company had preemptively completed the recent space experiment - the first "static ignition" test of the world's largest rocket booster.
SpaceX super heavy rocket is not only special in shape, but also different in material from conventional rockets. Currently, conventional rockets are generally made of aluminum alloy (aluminum magnesium and aluminum lithium alloy) and carbon fiber, while Musk uses 300 series stainless steel alloy.
What are the advantages of 300 series stainless steel alloy?
Musk said that the biggest advantage of using 300 series stainless steel alloy is that it is strong in toughness, cheap enough, fast in production, recyclable, and the lightest applicable material at present.
Advantage 1:
The performance and strength of high-quality stainless steel are improved by 50% at not too low temperature. Most steel will become very brittle at low temperatures, such as typical carbon steel. When you spray liquid nitrogen upward and hit it with a hammer, it will shatter like glass. This is true for most steels, but not for stainless steels with high chromium nickel content. Chromium nickel will increase the strength of stainless steel and improve its ductility. So, even at minus 330 degrees Fahrenheit, this stainless steel has 12% to 18% ductility, is very tough, very strong, and has no fracture problem.
Advantage 2:
In terms of price, the cost of carbon fiber is 135 dollars per kilogram, and there is about 35% scrap rate. The price of 301 stainless steel is 3 dollars per kilogram, which is much lower than that of ordinary rocket carbon fiber.
Advantage 3:
In addition, the recyclability of stainless steel greatly reduces the cost of rocket production, which is environmentally friendly and energy-saving.
With the development of the world's aerospace industry and stainless steel technology, stainless steel has been used more and more widely in aerospace industry. For corrosion resistant applications, the austenitic stainless steel grade 1.4301 (AISI 304) and its derivatives are suitable for mild environments (such as cabin components, internal fuel tanks, etc.) that do not exceed 200ppm, and the grade 1.4401 and its derivatives are more suitable for environments where chloride exists in the atmosphere.
High temperature resistance and oxidation resistance, grade 1.4301 (AISI 304), 1.4401 (AISI 316) and their derivatives show mild oxidation resistance, and are suitable for high temperatures up to 870 ℃.
For applications where oxidation resistance is the main characteristic requirement, 1.4818 (ASTM S30,415), 1.4835 (ASTM S30,815), 1.4833 (AISI 309), and 1.4845 (AISI 310) can be used. These ratings can withstand temperatures of 1150 degrees Celsius.
