One. Common cooling method after forging

1. High carbon steel and high alloy steel, in order to prevent surface cracking, it is necessary to cool after forging, furnace cooling, sand burying or slow cooling before baking, and then heat treatment in time.

2. Austenitic stainless steel needs to be poured into water immediately after forging. The purpose is to maintain its existing grain size as soon as possible, so as not to grow. At the same time, it is also undesirable to have more internal tissues or particles precipitated, and then to be solution treated.

3. All other conventional low-carbon steel and medium-low alloy steel forgings must be air-cooled after forging. The purpose is to make the cooling uniform, the organization uniform and the performance uniform, to prevent the growth of crystal grains and the appearance of mixed crystals, and to facilitate the writing of signs. The surface temperature of the ferrous metal forgings before being heat-treated in the furnace should not be less than 50°C to prevent white spots.

2. Cooling requirements for conventional low-carbon steel and alloy steel forgings

1. Large forgings (usually weighing more than 500kg or plane size greater than 300mm) are generally not allowed to be placed directly on the ground to cool, because it will cause uneven cooling on the upper and lower sides and uneven organizational performance.

2. For the post-forging cooling of conventional large forgings, there are three reasonable methods: ① air cooling by padding; ② air cooling by padding, such as on a horn or a colder forging previously forged; ③ upper and lower layers when stacked Between the padding, usually calculated at 10% height, that is, the height of 1000mm section should be 100, the height of 2000mm 200 and so on.