Surface Treatment Techniques for Common Stainless-Steel Flanges - Stainless Steel Flange Exporter Factories and Suppliers

The typical surface treatment methods for stainless steel flanges include the following techniques:

Surface natural color whitening treatment.

During the processing of stainless-steel flanges, a black oxide layer forms after rolling, forging, welding, or heat treatment. This hard gray-black oxide layer primarily consists of two components, NiCr2O4 and NiFe2O4. Previously, hydrofluoric acid and nitric acid were commonly used for solid corrosion removal. However, this method is costly, environmentally polluting, harmful to human health, and corrosive, and is thus being phased out. Currently, there are two primary methods for treating oxide layers:

50. The sandblasting (shot) method primarily involves using microglass beads to spray and remove the black oxide layer from the surface.
50. Chemical method: Employing pollution-free pickling passivation paste and a non-toxic cleaning solution containing inorganic additives at room temperature, the stainless-steel flanges are leached to restore their natural color to white. Following treatment, they exhibit a dull appearance. This method is well-suited for large and intricate products.

Surface Mirror-Bright Treatment Method

Depending on the complexity of stainless-steel flange products and user requirements, specular gloss can be achieved through various methods such as mechanical polishing, chemical polishing, and electrochemical polishing.

Surface coloring

Coloring stainless steel flanges not only provides them with a variety of colors, enhancing product diversity but also improves their wear and corrosion resistance.

The coloring methods of stainless-steel flanges are as follows:

50. The chemical oxidation coloring method involves the formation of a colored film through chemical oxidation in a specific solution. This includes techniques such as the dichromate method, mixed sodium salt method, vulcanization method, acid oxidation method, and alkaline oxidation method. While "dipping" is commonly employed, ensuring consistent color across a batch of products requires control using a reference electrode.
50. The electrochemical coloring method involves the formation of a colored film through electrochemical oxidation in a specific solution.
50. Ion deposition oxide coloring method, chemical method: The stainless-steel flange workpiece is placed in a vacuum coating machine for vacuum evaporation plating. For instance, titanium-plated watch cases and bands typically appear golden yellow. This technique is ideal for mass production processing. However, due to significant investment and high costs, it may not be cost-effective for small-batch products.
50. High-temperature oxidation coloring method: The workpiece is immersed in a specific molten salt and maintained at certain process parameters to develop a certain thickness of oxide film, resulting in various colors.
50. Gas-phase cracking coloring method: This method is relatively complex and is seldom employed in industrial applications.

The practicality of stainless-steel flanges

Certain steel structure equipment in our country operates in complex environments characterized by high temperatures and pressures. The primary concern regarding metals is their corrosion resistance, heat resistance, and overall performance. Consequently, the demand for stainless steel flanges is steadily increasing as they ensure equipment containing them remains free from corrosion, pitting, and wear. Stainless steel flanges are also among the most robust metal materials available.

The popularity of stainless-steel flanges primarily stems from their excellent corrosion resistance, ensuring structural components maintain their integrity over time in engineering designs. Chrome stainless steel stamping flanges also combine mechanical strength with high extensibility, facilitating easy processing and manufacturing of components to meet the requirements of architects and structural designers. While all metals react with oxygen in the atmosphere to form an oxide film on the surface, ordinary carbon steel's iron oxide oxidizes, leading to corrosion expansion and eventual hole formation. Electroplating with paint or oxidation-resistant metals like zinc, nickel, and chromium is commonly employed to protect carbon steel surfaces.

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