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Stainless steel plate appearance processing requirements of the tool and stainless steel plate surface into which kinds

Stainless steel plate appearance processing requirements of the tool and stainless steel plate surface into which kinds

Time:2022-04-02 Source:Wuxi Jianuo Special Steel Co., Ltd.

Stainless steel exterior mirror polishing is a variety of stainless steel exterior treatment, is after removing the exterior roughness and oxide skin and show the metal nature (similar to the effect of mirror reflection), the general appearance of its roughness value Ra ≤ 0.05 μm, the exterior brightness is greater than 10, to be called “mirror”.

Stainless steel mirror polishing based on polishing methods, common mechanical polishing, chemical polishing and electrochemical polishing three ways.

Currently more commonly used mirror polishing equipment is mainly to stainless steel plate or other types of metal plate through the adjustable pressure of the grinding disk counterclockwise rotation, correction wheel with open workpiece rotation, gravity pressure on the workpiece, plus the matching grinding emulsion (mainly metal oxides, inorganic strong acid, organic slicker and weak alkaline cleaning agent intermingled), the workpiece and grinding disk for relative running friction, to reach grinding and polishing purpose. The mirror polishing machine can be divided into three steps: grinding, polishing and regrinding; the matching abrasives, grinding materials and abrasive liquids are also different according to their different sections.

Various materials and thickness of stainless steel plate can be processed into different levels of mirror effect; due to the existence of macroscopic unevenness of the parent material (its appearance roughness level Ra value is generally da, to first grind its appearance roughness to a certain value (Ra ≤ 0.8μm), and then after grinding and regrinding way to stop grinding until the “mirror surface “.

There are many kinds of stainless steel appearance state, the general appearance as a mirror grinding master batch mainly 2B, 2BB, 2D, BA, No. 1, etc., the material suitable for mirror grinding mainly SUS304, 304J1, 316L, 201, 202, 430, 441 and other austenitic, ferritic stainless steel, the final mirror effect is also due to its parent material used and the appearance of the resolution;. Generally speaking, the polishing effect of 300 series stainless steel is slightly better than other series of materials, BA exterior polishing effect is the best, 2B is the second, No.1 is the worst.

In addition, polishing emulsion, polishing machine and polishing emulsion circulation system contact, coupled with the corrosion of various types of acidic and alkaline substances, the request polishing emulsion and polishing machine are to have a good corrosion resistance. In addition, due to the polishing machine high-speed rotation and metal plate friction to form a large amount of heat (especially austenitic stainless steel thermal conductivity is very poor); due to grinding work will generate a lot of heat in the same area, will form a metal appearance stress changes, which affects the physical state of the metal micro-variation, and ultimately incurred the flatness of the metal, so the request polishing equipment and polishing environment are to have good heat dissipation conditions.

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Stainless steel appearance processing grade, characteristics and use

Original surface: NO.1

Hot-rolled surface after the application of thermal treatment and pickling treatment. Commonly used for cold-rolled materials, industrial tanks, chemical industry installation, etc., the thickness is thicker from 2.0MM-8.0MM.

Blunt surface: NO.2D

After cold-rolled by hot treatment, pickling, its material is soft, the appearance of snow-white luster, for deep stamping processing, such as automotive components, water pipes, etc.

Matte surface: NO.2B

Cold rolled, hot treated, pickled, and then finely rolled to give a moderately shiny appearance. Because the appearance is lubricated, it is easy to regrind and make the appearance brighter, and it is widely used, such as tableware, building materials, etc. After adopting the exterior treatment to improve the mechanical properties, it can meet all the applications.

Coarse sand: NO.3

Products ground with 100-120 abrasive belts. It has better gloss with discontinuous coarse grain. Used for interior and exterior decorative materials of buildings, electrical products and kitchen equipment, etc.

Fine sand: NO.4

Products ground with 150-180 grit abrasive belts. It has better gloss, discontinuous coarse grain, and finer stripes than NO.3. Used for baths, interior and exterior building decoration materials, electrical products, kitchen equipment and food equipment, etc.

#320 Product ground with #320 abrasive belt. It has better gloss, discontinuous coarse lines, and finer stripes than NO.4. Used for baths, interior and exterior building decoration materials, electrical products, kitchen equipment and food equipment, etc.

HAIRLINE: HL NO.4 is produced by continuous grinding of appropriate grit polishing belt to produce abrasive patterns (subdivision 150-320 numbers). Mainly used for architectural decoration, elevators, doors and panels of buildings, etc.

Bright surface: BA

A product obtained by cold rolling, bright annealing, and flattening. Exterior gloss is excellent and has high reflectivity. It has a mirror-like appearance. Used for home appliances, mirrors, kitchen equipment, decorative materials, etc.

Processing stainless steel on the request of the tool

1. Select the geometric parameters of the tool

When processing stainless steel, the geometric shape of the cutting part of the tool, the general should be thought about from the front angle, the choice of the rear angle. In the selection of the front angle, we should think about the chip roll groove type, with or without chamfering and edge inclination angle of positive and negative angle size and other elements. Regardless of what kind of tool, processing stainless steel must be used when the larger front angle. Increase the front angle of the tool can reduce the resistance encountered in the process of chip cutting away and clearing out. The back angle selection is not very strict, but should not be too small, the back angle is too small and easy to produce serious friction on the exterior of the workpiece, so that the processing surface roughness deterioration, accelerating tool wear. And due to intense friction, strengthening the effect of hardening of the stainless steel exterior; tool back angle should not be too large, the back angle is too large, so that the wedge angle of the tool is reduced, reducing the strength of the cutting edge, accelerating the wear of the tool. Usually, the back angle should be appropriately larger than when processing ordinary carbon steel.

The choice of the front angle from the cutting heat generation and heat dissipation, increase the front angle can reduce the generation of cutting heat, cutting temperature is not too high, but the front angle is too large due to the reduction in the volume of heat dissipation of the cutting head, cutting temperature instead of rising. Reduce the front angle can improve the cutting head heat dissipation conditions, cutting temperature may be reduced, but the front angle is too small, the cutting deformation is serious, cutting the heat generated is not easy to dissipate. Theory shows that taking the front angle go = 15 ° – 20 ° is the most appropriate.

The choice of the back angle rough machining, strong cutting tool requires high cutting edge strength, should take a smaller back angle; finishing, the tool wear mainly occurs in the cutting edge area and the back tool surface, on stainless steel, such as easy to present machining hardened material, after the tool surface friction on the quality of the machined appearance and tool wear, a reasonable back angle should be: processing austenitic stainless steel (185HB below), the back angle can be 6 ° – 6 °. After the angle can be 6 ° – 8 °; processing martensitic stainless steel (250HB above), after the angle to take 6 ° – 8 °; processing martensitic stainless steel (250HB below), after the angle of 6 ° – 10 ° is appropriate. -10 ° is appropriate.

The size and direction of the edge inclination angle, the direction of the flow of chips, a reasonable choice of edge inclination angle ls, usually take -10 ° – 20 ° is appropriate. In the micro fine turning outer circle, fine turning hole, fine planing plane, should use a large edge inclination angle tool: should take ls45 ° – 75 °.

2. Tool material selection

The request of the toolholder material processing stainless steel, due to the large cutting force, so the toolholder must have sufficient strength and rigidity, in order to avoid chattering and deformation in the cutting process. This requires the use of the appropriate large cross-sectional area of the tool bar, but also should use the higher strength of the material to manufacture the tool bar, such as the use of tempered 45 steel or 50 steel.

The request of the tool cutting part of the material processing stainless steel, request the tool cutting part of the material has a high wear resistance, and can maintain its cutting performance at higher temperatures. At present, the commonly used materials are: high-speed steel and cemented carbide. Because the high-speed steel can only adhere to its cutting performance below 600 ° C, and therefore should not be used for high-speed cutting, but only for processing stainless steel at low speed conditions. Because the carbide than high-speed steel has better heat resistance and wear resistance, so the tool made of carbide material is more suitable for stainless steel cutting process.

Tungsten carbide is divided into two categories: tungsten-cobalt alloy (YG) and tungsten-cobalt-titanium alloy (YT). Tungsten cobalt alloy has good toughness, made of tools can be used with a larger front angle and sharpened sharper edge, easy to deform the chips in the cutting process, cutting light and fast, the chips are not easy to stick to the knife, so in general, tungsten cobalt alloy is more suitable for processing stainless steel. Especially in the vibration of rough machining and intermittent cutting processing conditions should be used tungsten cobalt alloy inserts, it is not like tungsten cobalt titanium alloy as hard and brittle, not easy to sharpen, easy to collapse the edge. Tungsten cobalt titanium alloy has better red hardness and is more wear-resistant than tungsten cobalt alloy under high temperature conditions, but it is more brittle and not resistant to impact and vibration, and is commonly used for stainless steel finishing tools.

The cutting performance of the tool material is related to the durability and consumption rate of the tool, and the process of the tool material affects the manufacturing and sharpening quality of the tool itself. It is advisable to choose high hardness, anti-bonding and good toughness tool material, such as YG carbide, it is best not to choose YT carbide, especially in the processing of 1Gr18Ni9Ti austenitic stainless steel should be absolutely prevented from choosing YT carbide, because the stainless steel titanium (Ti) and YT carbide Ti in the affinity for cooperation, the chip is easy to take away the Ti in the alloy, prompting the tool The wear is increased. Consumption theory shows that the choice of YG532, YG813 and YW2 three grades of material processing stainless steel has a better processing effect

3. The choice of cutting dosage

In order to suppress the generation of chip tumor and scale thorn, improve the appearance of quality, with carbide tools to stop processing, cutting dosage than turning ordinary carbon steel workpiece slightly lower, especially the cutting speed should not be too high, the general recommended cutting speed Vc = 60 — 80m/min, the depth of cut ap = 4 –7mm, feed f=0.15–0.6mm/r is appropriate.

4. The request of the tool cutting partial appearance roughness

Progressive tool cutting local appearance brightness can reduce the resistance of the chip composition curl, and improve the durability of the tool. Compared with the processing of ordinary carbon steel, processing stainless steel should be appropriately reduced cutting dosage to slow down tool wear; at the same time to choose the appropriate cooling smooth fluid, in order to reduce the cutting heat and cutting force in the cutting process, to extend the tool life.

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