Welding and grinding go hand in hand

08/02/2021

If you weld, you grind. This is because both the preparation of a weld seam and the post-processing are important in achieving a high-quality joint. Abrasives clean the area to be welded, take on the task of beveling, and flatten the seam. The demands on the tool are enormous: it needs to produce large quantities with consistently high quality, to remove a large amount of material and to take into account the properties of the material. This means, for example, avoiding the discoloration of heat-sensitive materials and at the same time reliably processing difficult-to-machine alloys.

If discoloration occurs, the components have to be reworked or remanufactured. Whether additional work is required or material has to be scrapped, both cases are cost drivers. Selecting the right abrasive can prevent discoloration. Grinding-active additives in the top size coat reduce the temperature in the processing zone, so that no discolouration occurs in the first place. Materials that are difficult to grind, such as Inconel or titanium alloys, place special demands on the abrasive: Abrasive grains that are both very hard and very tough are required in order to penetrate the material and not break down in a random manner. Ceramic grains combine both these properties.

Abrasives as cost cutters in the factory

In addition to the technical requirements for machining processes, the cost-effectiveness of the tools and operating resources used is also a key issue. In addition to personnel costs, the main factors here are procurement and warehousing costs, as well as expenses for energy, machinery maintenance, the acquisition of new machines, and downtimes. Powerful abrasives with a long service life reduce costs for procurement and storage.

For abrasives, in particular, the time factor is critical: the faster the weld area is beveled and the seam is flattened, the more workpieces can be machined per shift. And the more aggressive the abrasive, the higher the stock removal rate.

Ceramic abrasive grains unleash their full potential in these applications: they remove more material than conventional products and are therefore particularly efficient. Geometrically shaped ceramic grains such as VSM ACTIROX achieve the highest level of performance. The triangular grain breaks down in a very uniform and defined manner, continuously producing new sharp cutting edges in the process. At the same time, it ensures an exceptionally aggressive initial cut. Its full capability is thus evident from the first second of use. The grinding tool achieves higher stock removal rates, works faster and thus increases productivity.

Thanks to the high aggressiveness of ACTIROX belts, the user achieves the greatest possible stock removal. This has a positive effect on the machine - lower energy consumption, longer operating times and reduced repair costs. And the machine operator benefits too, since less effort is required. Machine vibrations are also reduced, as are noise levels. The burden on employees is reduced and downtime is minimized.

50 % less working time per weld

ACTIROX abrasives are available as belts and discs in many different dimensions and thus also fit existing machines. Weld seams on small components of housings, for example, can still be removed on the backstand grinder as per the company's established procedure. If the ACTIROX AF799 and AF890 fiber discs are supplemented with suitable back-up pads, the performance is even further improved. This is because the design of the pad influences the grinding result. Medium-hard back-up pads allow the fibre disc to adapt to contours. As the hardness increases, the aggressiveness and thus also the stock removal rate of the disc increase.

Rigorously tested

VSM AG tests all of its products under practical conditions in its in-house Competence Centre at the company's headquarters in Hanover, and exchanges ideas and works closely with partners from industry and trade. The ACTIROX AF890 fiber disc took exactly 2 minutes to remove a weld seam 200 mm in length on stainless steel 1.4301. The previously used ceramic grain fiber disc took 4.5 minutes. This is a saving of 55% working time per weld. VSM's fiber discs also perform significantly better than the flap discs commonly available on the market - popular due to the grain reserve in the overlapping flaps. In direct comparison, the service life of AF890 exceeded that of the flap disc by more than 30 % when levelling welds.

The ACTIROX AK890Y grinding belt has been tested with difficult-to-machine materials. It achieved an increase in performance of over 15 % with titanium alloys, and more than 20 %. with chrome vanadium steel.

The right abrasive for higher productivity

Abrasives are essential when it comes to preparing and post-processing welds. They not only achieve the required engineering results, but also represent an important economic factor in that they increase productivity and reduce costs at the same time. Choosing the right grinding tool is crucial in this.