What are the surface treatment processes of stainless steel?
The surface treatment processes of stainless steel we often see: brushed, mirror, sandblasting, titanium plating, metal etching, anti-fingerprint, etc., have many wonderful applications in interior decoration:
Let’s take a look at the surface treatment process of stainless steel in detail:
Brushed (Frosted)
Usually, after the surface of stainless steel is processed by mechanical friction, the surface state is a straight line (also called frosted), including wire drawing, and grain, and corrugation.
Processing quality standard: the texture is uniform in thickness and depth, and the texture on each side of the product is natural and beautiful according to the design and construction requirements. The bending position of the product is allowed to have a slight messy texture that does not affect the appearance.
Mirror
A bright surface effect obtained by using high-quality oilstone, diamond abrasive paste and different grades of sandpaper through rough grinding, medium grinding and fine grinding by polishing and grinding equipment.
Processing quality standard:
No sand and hemp texture (orange peel).
The surface should be flat, and there should be no concave protrusions or undulating wavy surfaces (distorting mirrors).
There are no residues, sand holes, scars, impurity spots, bruises, scratches on the blank surface.
The brightness reaches 8K, and the brightness of the finely ground mirror exceeds 8K.
Glossary definition: “8” in 8K refers to the ratio of alloy composition, “K” refers to the level of reflectivity after polishing (K level is the mirror reflection level), 8K mirror is chrome-nickel alloy The specular grade embodied by the steel.
Titanium Plating
Also called stainless steel titanium/zirconium coating, it is to form an ion film layer of titanium/zirconium compound on the surface of stainless steel in a vacuum container, and the film layer can not fade for many years in the outdoor environment.
Titanium plating principle: In high temperature, vacuum titanium gold furnace, titanium and zirconium metals are ionized by the glow discharge of inert gas to ionize metal or alloy vapor, and the ions are accelerated by an electric field to deposit on a negatively charged stainless steel plate, thereby forming a color Rich and colorful metallic film.
Sand Blasting (Shot)
Compressed air is used as the power to form a high-speed jet beam to spray the spray material (quartz sand, corundum) onto the surface of the workpiece to be processed at high speed, so that the surface of the board presents a fine bead-like sand surface, forming a unique decorative effect
Metal Etching
The process principle of chemically etching patterns and texts on the surface of etching stainless steel is to cover the part of the surface that will not be etched with a special corrosion-resistant layer, shield the acid, so that the acid can only contact the surface of the part to be etched, and achieve the etching pattern and pattern from the surface. The purpose of the text.
Anti-Fingerprint
Stainless steel anti-fingerprint plate is a kind of composite coating plate obtained after anti-fingerprint treatment on the surface of stainless steel. The coating method is mainly roller coating.
The process of anti-fingerprint treatment is originally to meet the needs of users in the field of home appliances. During the production process, due to the needs of the process, many parts are manually touched many times, and sweat stains are easy to form pollution on the surface of the parts, which affects the appearance. The research and development of anti-fingerprint board That’s how it starts.
There are more than a hundred types of stainless steel. In the process of processing parts, we are more exposed to 201 stainless steel, 304 stainless steel, 316 stainless steel, and 430 stainless steel.
- The corrosion resistance of stainless steel mainly depends on the proportion of alloy elements contained in the material itself, so if the proportion of alloy is high, or it is processed and used improperly, what we commonly call “stainless steel” will still rust.
- Both 200-series and 300-series stainless steels contain nickel
- 430 stainless steel does not contain nickel
- The corrosion resistance of 201 is slightly higher than that of 430
- Corrosion resistance is roughly
- 316>304>201>430
Therefore, there are often cases where some suppliers replace materials with inferior ones. Here I will talk to you about the pre-control method:
Stainless steel material model replacement – the most typical
If the project department usually uses the 304 model without specifying the material requirements, at this time the supplier often replaces the 304 with 201 (easy to rust), 202 (containing nickel), 304J1 (less prone to rust) and other materials model.
Among them, the unit price of materials is calculated in tons, and the loss here is very large compared with the quantity:
- 201 is about 8500 a ton cheaper than 304
- 202 is about 3500 a ton cheaper than 304
- 304J1 is about 3000 a ton cheaper than 304
Countermeasures for reminder items:
- The project department should clarify the material requirements before production or when bidding, and require the supplier to make a written commitment to clarify the penalty regulations for replacement.
- Material supply center introduces related spectral analysis equipment, regular material self-inspection and so on.
The supplier’s “small thinking” in deepening the plan – the easiest to ignore
■ The thickness dimension is intentionally increased
In the decoration project, the stainless steel door cover with a width of about 400mm is generally 1.2mm thick, and the supplier may deliberately mark the drawing as 1.5mm or 2.0mm when deepening.
The actual thickness of 1.0mm can meet the quality requirements for small lines with a development surface of no more than 100mm, and the supplier will mark the drawing as 1.2mm or 1.5mm thick when deepening. Increased stainless steel deepening thickness will lead to a substantial increase in price.
■ Simple process is complicated
In some blueprints, the stainless steel is simply dimensioned, without detailed nodes, and the supplier may deliberately increase the difficulty of the process when deepening, and the complex process requirements will result in an increase in price.
Remind the project department of the countermeasures:
- The project department should strictly review the deepening plan, and standardize the thickness according to the quality requirements if the owner does not clearly stipulate.
- Or the company can deepen the bidding in a unified way to ensure that the suppliers are under the unified standard during the bidding, instead of relying on the suppliers to deepen, so that there are loopholes to exploit.
- Strengthen the ability training of project professional deepening personnel, or use the stainless steel team to check to ensure the rationality of deepening.
■ Quotation adopts process and material separately – the most difficult compromise
Due to various reasons, the price of many projects is handled in a tentative manner. In order to get the project, the supplier deliberately adjusted the material cost, resulting in the illusion of cheapness, and then increased the unit price of the process cost during the final settlement. Due to this imbalance, the overall price has increased.
Remind the project department of the response plan:
For tentatively priced materials, the process standards shall be unified, and the quotation shall adopt a standardized price list, which is detailed to the cost of grooving and bending.