Welding of stainless steel.
Do not expose the product to the harmful and destructive effects of alkalis and acids during further processing. After welding, a thin layer of oxide forms on the surface of the product. It weakens the compound’s resistance to corrosion. Corrosion is divided into electrochemical and chemical.
- Electrochemical – is the collapse of the metal in the electrolytes.
- Chemistry is the destruction of the metal by exposure to the environment.
Methods for processing stainless steel after welding
To do this, you need a special protective suit and mask. As a rule, sulphuric, hydrochloric, hydrofluoric or nitric acid is used in the engraving in the form of gels, pastes, aerosols and sprays. For pickling seams, it is best to use a paste with a very thick consistency. The paste must be applied with a brush, a very uniform level.
- The first method is acid etching.
- Resizing with hydrochloric and sulphuric acid. It is necessary to observe the strictest control of the saturation of the solution and the temperature.
- Rinse with water.
- Immersion in a bath with a mixture of hydrofluoric and nitric acid.
- Thorough rinsing
The acid pickling process of stainless steel.
Acid vapours are formed in the air, which requires a serious approach to the protection of the skin and respiratory organs. This process has many different variations with the concentration of the composition, the time and the sequence of actions.
The electrolytic etching is one of the methods of acid attack. An electric current, direct or alternating, is passed through the bath but has a mechanical effect. The methods described above are very complex and require a considerable financial investment.
The second method is engraving with mixtures of acids ready after welding.
- First, remove all traces of dirt, dust and grease stains. The composition is applied for half an hour.
- Final treatment with a passivator.
This is an easily accessible cleaning method. As far as precautions are concerned, the paste must not be heated, exposed to direct sunlight. There must be good ventilation in the room, these compounds have a pungent and unpleasant smell. If the paste comes into contact with the skin, rinse immediately with water.
Mechanical methods and heat treatment after welding
Minimum processing is the removal of slag and scale by grinding the joint with a stainless steel brush. In some cases, this is not sufficient and additional chemical treatment is required. Grinding with fine-grained sandpaper is very common.
Etching products from stainless steel with acid.
Mechanical methods are sandblasting, liquid abrasive and water sandblasting. A prerequisite: the minimum iron content in the sand. After this cleaning, the surface is passed.
The heat treatment of stainless steel is divided into several types: hardening (maximum temperature and rapid cooling), annealing (metal heating and slow cooling), normalization (similar to annealing, the difference is that cooling occurs in the fresh air, not in the furnace), hardening (held after extinction).
The correct heating of the workpiece depends on the final result and the quality of the product. Under the influence of heat, the metal changes its structure and properties. When overheated, it acquires an unwanted coarse-grained structure. Monitoring the heating temperature must be very careful. For example, Burnout is a marriage that is no longer subject to correction.
Chemical-thermal treatment of stainless steel – heat treatment with the application of various elements on the surface (chrome, aluminium, nitrogen, etc.).
istics of stainless steel
This cleaning method will help to eliminate all contamination from the metal surface, as well as creating the necessary corrosion resistance, will help to improve the appearance of the product and keep it away from possible contamination in the future. Passivation is a protective film that forms on the metal surface and protects it.
reliably from damage and destruction. The passivation must be applied for half an hour and is possible on a wet surface.
After the required time has been maintained, the passivation is removed from the product. A water compressor is normally used for this purpose.
In order for the product to acquire a finished appearance after welding, the welds must be machined with a grinding machine.
After welding, it is necessary to bring the product to a correct and finished appearance, giving it lustre, lustre and lustre. Thanks to the use of new technologies in polishing, the time devoted to this work have been significantly reduced and the quality has increased.
Polishing is the use of a special grinding machine. Mode, you must choose the one recommended by the manufacturer. Features polished tubes are that they have an impeccable appearance are durable and durable. Polishing can be manual, ultrasonic and mechanical. Normal types of sandpaper, abrasive materials, files can be suitable at home.
The first step is to get rid of the rough seam, to make the surface smooth and uniform. To complete this task you will need a circle of development. It will easily remove the rough seam, it will remove the scale. Now the surface is ready for further action.
The second step is to remove the risks from the first processing. The surface is brought into a state close to the final. Sometimes at this stage, you can stop. The surface is already beautiful.
The third step is the final polishing. Shine the metal on a mirror. At the same time, when you polish stainless steel, the microscopic defects are removed from the surface and, if polished, the coarse ones.
Classification of welds by position in space.
When doing this work, don’t forget to prepare yourself well. Wear a mask to avoid dust in your eyes. Polished products are subject to clearly visible defects: scratches, scratches and so on. You will need grinding heads with abrasive belts.
To achieve the desired result, the steel is polished in several steps. Remember that the right materials and tools will allow you to reduce working time and improve its quality, which guarantees excellent results.
Finished products are ground using abrasive paper. This material has a paper or fabric base with a very different grain coating. Wet sanding is carried out with impermeable skins. The coatings can be made of glass and silicon. Grinding is the final step in the stainless steel working process after welding. It evenly removes all the upper layers.
Materials you will need:
- grinding wheels with different grain sizes;
- wood glue;
- polishing paste.
A grinder is required for grinding welds on stainless steel products.
The first thing you need to do is to remove the metal influx from the weld. You can do this grinder. If the surface is sufficiently smooth and uniform, you can immediately proceed to the second stage. Prepare a felt circle, using the normal trowel, apply the carpenter’s glue on the surface of the piece. Walk carefully and carefully on the abrasive spring, which can be obtained from the emery fabric.
Then sand the surface three or four times. The size of the abrasive should be reduced. The surface of the stainless steel must be washed after each grinding.
It should be perfect, absolutely smooth and uniform, without sharp edges. Otherwise, you have to do everything again. In the next step, you will need a felt disc and a polishing paste. It’s best to find a diamond with a grade of grain that matches your metal. This is a glossy finish that removes visible risks. You’ll see how the surface changes and becomes smoother.
A few words in conclusion
So, professionals have been known for a long time. The material “stainless steel” has entered closely into the life of every person. It has a place almost everywhere, even in a modern kitchen, many items are made of high-quality stainless steel. Such popularity is due to the good characteristics and properties of this wonderful metal.
After proper processing, it looks perfectly beautiful, in its mirror surface, you can see its own reflection. This material is one of the most resistant, resistant and durable. The stability of this material is simply incredible. But for that to happen, you’ll have to tinker a little.
Working with steel after welding is a rather laborious, complex and laborious task. It requires skill, professionalism and absolute precision of performance. It will be difficult for a novice home master to master this intricate science, but with the right and responsible approach, you will undoubtedly enjoy the result of the work.
Above all, do not forget the danger you may encounter during the execution of this work, it is very important to observe all precautions. And then come the experience, skills and dexterity you need.