One. Cooling method for common forgings after forming
1. High carbon steel and high alloy steel, in order to prevent surface cracking, it is necessary to forge stack cold, furnace cold, buried sand cold or furnace bake slow cooling, and then heat treatment in time.
2. Austenitic stainless steel needs to be poured into water immediately after forging. The goal is to keep its existing grain size as fast as possible without growing up. At the same time, it is not desirable to have more internal tissues or particles to be separated and then solution treated.
3. All other conventional medium and low carbon steel and medium and low alloy steel forgings must be air-cooled after forging. The purpose is to make it evenly cooled, uniform in structure and uniform in performance, prevent grain growth and mixed crystals, and facilitate writing marks. The surface temperature of the ferrous forgings before heat treatment shall not be less than 50 °C to prevent white spots from appearing.
two. Cooling requirements for conventional medium and low carbon steel, alloy steel forgings
1. Large forgings (usually weighing more than 500kg or larger than 300mm in plane size) are generally not allowed to be directly placed on the ground for cooling, because uneven cooling will occur on both sides, and the structure performance will be uneven.
2. For the post-forging cooling of conventional large forgings, there are three reasonable methods: 1 padding air cooling; 2 setting up air cooling, such as on a horn or a previously forged cold forging; 3 when laying steeply To be padded, it is usually calculated at a height of 10%, that is, a cross section of a thousand millimeters is required to be 100, a height of 200 mm, and a height of 200 mm.