When selecting the particle size of steel shots, you can use larger steel shots to improve the liquidation efficiency if you are satisfied with the external fineness requirements. Use graded steel shot. Graded steel shots are composed of steel shots with a surface size of about 50% and progressively smaller steel shots. The impact force and the masking rate are coordinated, which can lose the highest liquidation efficiency and lower appearance fineness (compared with multi-grain steel Compared to pills). When liquidating the cylinder of a car, the original use of s550 (~ 1.5mm) steel pellets with a large number of grains was required for 60 seconds, and the appearance fineness value was R. 15 ~ 25ttm, and after using $ 460 (1.2mm) graded steel shot, the liquidation time is 55s, and the appearance fineness value is R. 12.5-20urn.
Graded steel shots consist of 50% or so surface size steel shots and progressively smaller steel shots
In the process of consumption, each steel shot is a process that becomes less wear and tear, so the particle size of each steel shot changes from time to time. Since the hot spot changes with the particle size of the steel shot, in order to ensure that the thermal particle size / ram distribution gradually approaches the ordinary curve. If you add too much at one time, the appearance of the casting will become fine immediately; if you do not add material for a long time, although the quality of the appearance of the casting will improve, the liquidation efficiency will drop significantly.
Graded steel shots consist of 50% or so surface size steel shots and progressively smaller steel shots
The liquidation process can remove the sticky sand and oxide scale on the surface of the casting and expose the metal body. If the liquidation is continued, the original appearance of the metal of the casting can be changed and R can be changed. It tends to a certain value (related to the particle size of the steel shot). (a) The popularity of grading steel shots. (b) The particle size of steel shots becomes smaller. The change in the particle size of the hot-moving left shots does not change the point of influence. It is necessary to ensure that the mixing ratio of the shots does not change. Because the hottest is guaranteed to be accurate, the ability to ensure clearing efficiency. In the process of consumption, not only must the screening method be used to reflect the various mixing ratios of the mixed steel shots, but also pay special attention to the steel shots' supplement method, and actively replenish in time according to the consumption of the steel shots.