Manual mirror polishing of stainless steel
Manual grinding and polishing are still in the main grinding stage. Although robot grinding and polishing have gradually become regular, it must be said that robot grinding first takes up a lot of space. A large area is needed to place the robot, supporting machinery, and equipment. For small and medium-sized factories, the site area is limited. The temporary position of a robot may be the position of several workers, so generally, factories with small sites do not use intelligent grinding.
Secondly, small machinery and equipment. For small factories, small grinders of this type are available in addition to manual grinding. Most of the grinding will be done by machine tools, and manual grinding is used for some parts that cannot be completed by machines. This is for small parts or parts. Suppose the irregular weld scar of the finished product is ground, in addition to intelligent robots. In that case, it can only be ground manually, such as stainless steel water tanks, car frames, etc.
What are the specific processes and corresponding tools for manual weld grinding and polishing?
Of course, our main material is the welded steel pipe. The main purpose is to remove the welding marks from it and make it look smooth and smooth. The second is to polish the pipe to achieve the mirror-like effect we see in the store.
Generally speaking, angle grinders are used to grind weld scars, and the materials are different. Let's list a few of them.
The first type of flap disc with fiberglass: fiberglass flap discs are made by cutting abrasive cloth roll into corresponding abrasive cloth pieces, and then sticking them together to form a grinding material.
With an angle grinder, the high-speed rotating grinding disc can quickly remove weld scars, but its sharp grinding performance is easy to causes excessive grinding of the main body of the product and damages the main body in the hands of inexperienced workers, so it is not recommended for novices to use it, or it is the best choice when the weld scar grinding requires deeper grinding.
Flap discs are suitable for metal and non-metal materials that are difficult to teach hard, such as stainless steel, copper, iron, cemented carbide, etc.
The second type of non-woven abrasive hand discs: The overall material of the nylon abrasive disc is a bit like a fiber compound. The surface is not very hard. The abrasive particles are coated on the surface so that they can have a grinding effect without losing their softness.
Soft nylon sand discs also have good results in grinding weld marks. aluminum oxide nylon discs are mostly made of sticky and lock-on types. The sticky type is often called back velvet, which is used with a sticky disc. The lock-on type also has a special pad, but relatively speaking, the lock-on type abrasive is generally 1~3 inches in size, and the sticky type is mostly 4~6 inches in size.
Abrasive non-woven sand discs are suitable for grinding soft metals such as aluminum and zinc alloys.
The third type of grinding disc: also known as resin grinding sheet, is made of aluminum oxide and silicon carbide materials and has strong grinding force, but its consumption is also relatively fast.
With the use of angle grinders, high-speed rotation makes it consume faster and easier to replace grinding sheets.
There are also some grinding wheels, sanding belts, and other tools for grinding welds. I won't introduce them one by one here.
Weld grinding has always been a relatively uncomfortable process. Because it is not pleasant and uncomfortable without grinding, of course not. It is also not denied that there are certain sensory factors in this regard.
The main reason is also the reason that affects the appearance. But the most important thing is the problem of material matching. The unevenness of the weld scar makes it impossible for the product to be combined with other products.
In addition, the weld generally requires the residual height. The thickness of the weld is to maximize the welding effect of the main material and ensure that the weld will not be oxidized or corroded due to various reasons, so it needs to be polished.
For weld bead polishing, the commonly used materials are the above, and the tools are generally divided into arc and plane for manual use:
The two tools used for plane polishing are angle grinders suitable for various shapes and sanders suitable for plane polishing.
Tubular polishing is divided into right angles and arc angles:
Right angle: The selected material is generally a resin grinding wheel or a nylon wheel. The edges and corners of the grinding wheel can be filed accordingly according to the inner bending angle to make the edges and corners of the grinding wheel fit the inner weld of the polishing material.
Fox horn: Use a sanding machine to polish the area around the inner weld scar and the entire steel pipe to remove impurities and variegated colors. Make the material smooth and flat as a whole.
Here we use a handheld sanding machine and sanding belts of different grit numbers to perform preliminary to fine polishing.
The sanding belt grit number is selected from 60-3000 mesh sanding belts according to the different materials being polished. Of course, our steel pipes use sanding belts with four grit numbers of 400, 600, 1200, and 2000 mesh. From small to large, from coarse to fine.
After the finest sanding belt is polished, the mirror effect is initially achieved, but you will find that the steel pipe is not very clear, and at most, you can see a human figure. The next step is the last step of polishing.
First, choose a nylon sanding belt or nylon wheel according to the material for fine polishing and drawing, and finally use a cloth wheel with polishing paste to polish the workpiece.
Finally, the belt sander is still needed. This depends on the material. If it is a flat surface, it is better to use a sander. For tubular materials, we use a belt sander, a non-woven or wool sanding belt, and a polishing paste to continue polishing until the surface of the tube presents a mirror-like luster.
