JPS58186566A - Method of shot-peening steel plate - Google Patents

Abstract

PURPOSE:To greatly enhance the efficiency of grinding by centrifugal shot projection, by centrifugally projecting shots of 0.10-0.25mm. in grain size from a position of 900mm. or less in projection distance to peel scale off a steel plate. CONSTITUTION:The efficiency of grinding is independent of the distance of projection and maximum at 0.18mm. in the grain size of steel shots. The maximum efficiency of grinding is about 20% higher than that by a conventional method with steel shots of 0.30mm. or more in grain size. The use of the steel shots at the lower grain size of 0.10-0.25mm. leads to the economization of energy. The efficiency of grinding is high and nearly constant independently of the projection distance when it is 900mm. or less. The present method of shot-peening with steel shots of small grain size at a projection distance of 900mm. or less results in bringing a high grinding efficiency for an iron plate and economizing energy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shot blasting method suitable for removing scale from a steel plate.

In the conventional shot blasting method, in which scale is removed from a steel plate by colliding with centrifugally projected steel shot, steel shot with a grain size of 0.3 m or more is usually used in order to obtain a large impact energy from the shot. Since the steel shot that is fired bounces back after colliding with the steel plate, the centrifugal projector was usually installed at a quick distance from the steel plate.

By the way, recently, there has been a strong demand for energy saving in the shot blasting industry, and there has also been a demand for a shot blasting method that can obtain a polished surface with small irregularities for steel plates. For this reason, as a result of intensive research on these, the inventor of the present application has found that even with steel shot having a grain size of 0.3111 or less, scale can be removed better than before under certain conditions, and the unevenness of the polished surface is smaller than before. The present invention was made by focusing on this discovery.

The following will explain based on experimental examples. The projection density of the steel shot was set to 1 hiki, the projection speed was set to 73% ec, and the distance between the centrifugal projection device and the steel plate (hereinafter referred to as the projection distance) was set to 5.
30m, 7305g5.930IIll, and the steel shot particle size is 0.10B, 0.181111.
The cleaning rates when shot blasting a thin steel plate by changing the polishing rate to 0.30 wIk are shown in FIGS. 1 to 3. Furthermore, the projection speed of steel shot is 73+! /e. , and the particle size of the sheet E-) is 0.1
81111, projection distance 530M&, 730 words, 9
The cleaning rate when changing to 30 theories and 1200 cabinets is now shown in Figure 4.

From Figures 1 to 3, the cleaning rate becomes hMl higher when the steel shot grain size is 0.181B, regardless of the projection distance, and the cleaning rate at this time is higher than that of the conventional grain size of 0. .30
It can be seen that the improvement is about 2 (l) compared to when shot blasting is done with steel shot of 111 or more. It can be seen from FIG. 4 that the cleaning rate is high and almost constant regardless of the projection distance when the projection distance is 900 mm or less. Well, the projection distance is 90.
Shot blasting with fine grains of less than 0.0 mm can not only achieve a high cleaning rate in the case of steel plates, but also saves energy and energy. Throw this! The same thing happened when the 4th speed was 62r/B6c (not shown).

As is clear from the above explanation, the present invention has a particle size of 0.1
A shot of 0 to 0.25111 at a projection distance of 9QQas
Since the scale of the steel plate is peeled off by centrifugal projection from the following positions, particles with a particle size of 0.30 or more are removed over a distance.
Compared to the conventional steel plate polishing method, which uses centrifugal blasting from a fast position of 11,000 plows or more, the cleaning rate of centrifugal blasting of shots can be greatly improved, and as a result, centrifugal blasting It is possible to greatly reduce the amount of energy required for this, which produces excellent effects.

[Brief explanation of drawings]

Eko is a graph showing the experimental results based on the present invention.
The figure shows the polishing rate when the projection distance is set to 930 easy and the shot diameter is varied. Figure 2 shows the polishing rate when the projection distance is set to 730118 and the shot diameter is varied.
The figure shows the cleaning rate when the shot diameter is varied with a projection distance of 530 mm. Figure 4 shows the polishing rate when shot with a grain size of 0.18- is centrifugally projected at a projection speed of 7311/sec. The cleaning rates are shown when various changes are made. Patent applicant Shinsha Kogyo Co., Ltd. Shot 4F1.1 Figure 14 Figure 333-

Claims (1)

[Claims] In the shot blasting method of steel plate, in which steel shot is projected by a centrifugal projection device and collided with the steel plate, thereby peeling off the scale of the steel plate, the particle size is reduced to 010 to 0251.
11. A method of shot blasting a steel plate, characterized in that the steel shot is projected at a distance of 900 mm or less using a steel shot of 11.