Japan's most awesome patent

As early as the last century, Japan made a breakthrough in this field, and after years of painstaking development, Japan broke through many technical barriers here and obtained numerous patents in this field, directly leaving some European countries behind. Therefore, according to Japan's professionalism in this field, experts believe that Japan's steel metallurgical technology has surpassed China, tied the United States, and is at least 20 years ahead of the world.