Grate cooler hammer should have time limit
March 04, 2023
Hammer crusher hammer head with different service life, grate cooler hammer processing contract at the time of signing, has a special provision, that is clearly defined the use of the hammer head time limit. This is because of what reason? The head of the accessories department of Zhengzhou Dingsheng Engineering Technology Co., Ltd. made the following explanation:
The clinker cooler crusher is used to disperse the block clinker coming from the cooling end in the last stage of the grate cooler. Because the clinker has a certain temperature, for the large gold teeth hammer of the high manganese steel base, The normal use temperature of high manganese steel is below 50°C. With the increase in the use of temperature, it is equivalent to the tempering of high manganese steel.
The temperature of precipitation of carbides in the austenite of high manganese steel is 125°C. With the increase of tempering temperature and time, the precipitation of carbides in austenite is accelerated, and the carbides on the austenite matrix are accelerated. The number of diffuse precipitation increases. As the temperature is further increased and the holding time is prolonged, carbides will grow and grow. When the temperature exceeds 400°C, carbides will continue to form a continuous network of grain boundaries, and intra-crystalline needle-like carbides will appear as if they return to the as-cast state. organization.
However, when a temperature of more than 400°C occurs or a long period of time is 300°C, the impact toughness drops sharply and a so-called "toughness trap phenomenon" occurs. As a result, the impact toughness of the high-manganese steel decreases, the fatigue strength decreases, and the hammerhead breaks.
Therefore, although the hammers of the Dajinya material crusher have a long service life for crushing cement clinker, they cannot be used forever. Especially when the cooling effect of the grate cooler is poor and the high temperature clinker enters the crusher immediately following it, the internal temperature of the crusher is very high, and the grate cooler hammer is equivalent to long-term tempering in the tempering furnace. With the frictional heat generated by the hammer hole and the hammer shaft, the impact toughness and fatigue strength of the hammer handle will continuously decrease with the extension of time, and if the limit is reduced, it will break from the hammer handle.
Therefore, unlike the limestone crusher hammer head, the grate cooler hammer head can be used on the machine for a long period of time. Under normal circumstances, other manufacturers of high-manganese steel grate cooler hammer, without alloy, use 2-4 months, there is no time to change the impact toughness down. The Dajin dental grate cooler hammer produced by Dingsheng Company has generally been used for 4 to 12 months due to the large increase in wear resistance. This will result in the use of more than the specified hammerhead time limit, and the impact toughness of the hammer will drop and break.