JPS5929056A - Flame spraying method - Google Patents

Abstract

PURPOSE:To apply an ideal flame spraying treatment with interruption of air, dust, etc. by making a flame spraying chamber freely ventilatable by a ventilation and circulation system provided with a filter, connecting said system to a supply system for an inert gas and performing flame spraying in the flame spraying chamber under the supply of an inert gas. CONSTITUTION:The inside of a flame spraying chamber 1 is made freely ventilatable by a ventilating and circulating system 2 provided with a filter 3. The system 2 is connected to a supply source 4 for an inert gas. A blower 5 is driven and while the inert gas is circulated in an arrow direction, flame spraying is accomplished with a treatment device 7 for flame spraying. Since the inert gas to be circulated passes the filter 3, the dust, etc. produced in the treatment are removed by the filter 3 and a series of flame spraying treatments are accomplished in a clean atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal spraying method that improves the toughness, corrosion resistance, and adhesion of a thermal sprayed layer to a substrate. During thermal spraying, the surface to be processed is usually sandblasted as a pre-process to improve adhesion to the base material, and in the next thermal spraying process, thin thermal spray layers are stacked to a predetermined thickness. Form a sprayed layer. It is generally known that the sprayed layer formed in this manner has difficulty achieving desired adhesion and corrosion resistance because it contains oxides or other inclusions at the interface with the base material or between the sprayed layers. This is because the above steps are carried out in the atmosphere,
Moreover, since the compressed air used for sandblasting contains oil and moisture, the surface of the base material activated by sandblasting may be oxidized or altered, and inclusions such as oxides may be formed between layers during thermal spraying. This is thought to be the cause of the decrease in adhesion strength and acceleration of corrosion.

The present invention is characterized by forming a clean inert sprayed layer through a series of thermal spraying processes such as sandblasting, thermal spraying, and sealing.

The system is connected to an inert gas supply source, and the gist is to carry out the thermal spraying process in the thermal spraying chamber while the inert gas is ventilated by the continuous circulation system. The details of the figure are as follows. Reference numeral 1 indicates a thermal spraying chamber, and 2 indicates an inert gas circulation system. 3 is a filter provided in the circulation system 2, and 4 is an inert gas supply source. The inert gas, such as N2, CO2, Ar, or a mixture of two or more of them, supplied from the inert gas supply source 4 is passed through the circulation system 2 by the blower 5 as shown by the arrow in the figure. circulate. At this time, circulation system 2
Since the thermal spraying chamber 1 is configured therein, the thermal spraying chamber 1 maintains an inert gas ventilation state, and the thermal spraying chamber 1 is configured with an inert gas atmosphere. In such an atmosphere, a series of thermal spraying treatments are carried out by the thermal spraying apparatus 7, including sand blasting, cleaning of the sandblast surface, powder raw material thermal spraying J-1, and sealing for resin coating on the base material 5. Processing etc. are performed. A series of such thermal spraying treatments are all performed in a circulating inert gas atmosphere, and all gases used in each treatment are inert gases. For example, in sandplast processing, the gas used for sand spraying, the gas used for the cleaning process, the gas used for the powder raw material thermal spraying process, and the gas used for the sealing process are all supplied from the same source 4. This is done using an inert gas.

During the thermal spraying process, the circulating inert gas passes through the filter 3, so the dust etc. generated during each process is
removed by filter 3, therefore in a clean atmosphere,
A series of thermal spray treatments can be performed. If the pressure of the circulating inert gas rises in the processing of each step, the pressure may be adjusted by opening the damper 6 or the like. Reference numeral 8 indicates a conveyor-like sand recovery device, and 9 indicates a pressure detector for circulating inert gas.

As described in (5), the circulating inert gas is in a clean state, and a series of thermal spraying treatments can be performed in the ventilation state of such inert gas, so it is ideal for blocking air dust, etc. A thermal spraying process can be performed, and a thermal sprayed layer with excellent adhesion and corrosion resistance can be formed on the base material 6.

[Brief explanation of drawings]

The figure is an overall systematic explanatory diagram. Code 1・Thermal spraying room, 2・
- Inert gas circulation system, 3 - Filter, 4... Inert gas supply source, 5 - Base material, 6... Damper, 1... Thermal spray treatment device, 8. Conveyor-shaped sand collection device, 9... pressure detector.

Claims (1)

[Claims] The spray chamber is ventilated by a ventilation circulation system equipped with a filter, the ventilation circulation system being connected to an inert gas supply source;
A thermal spraying method characterized in that the thermal spraying process is carried out in the thermal spraying chamber in a state where an inert gas is ventilated by the ventilation circulation system.