The application of the results of hardness measurements and its modeling in CAD as a 3D model is considered. Different welding modes were applied and electrodes CT-15, OZL-8 and CL-11 were used as consumables. The test material is a hot-rolled pipe with a diameter of 159 mm made of corrosion-resistant steel 12X18N10T with a thickness of 6 mm. The electrodes were fused to half its length and removed from the electrode holder, after cooling the remainder of the electrode, it was reused. For scanning measurement of microhardness of samples with a load of 100 g, the scanning step was applied 0.5 mm. The use of modern software was able to more accurately simulate the test results on a 3D model. The samples are welded with CT-15 electrodes at a maximum current of 100 A. the hardness is over 450-550 HV, regardless of what the passage was. Similarly, when welding with OZL-8 brand electrodes, but only at low currents, the hardness exceeds 450 HV. In both electrodes, the hardness is increased. When using OZL-8 electrodes, samples welded at high currents have less hardness than at low currents. When welding with these electrodes, it is possible to use them in certain passages, for example, when surfacing the root layer of the seam. In the case of full penetration in high-current modes with CT-15 electrodes, the result differs little as in low modes.

Keywords: steel 12X18N10T, multi-pass welding, welding of austenitic steels, pipe, coated electrodes, welding modes, mechanical properties, macrostructure. Excel, Autodesk Inventor, CT-15, OZL-8, CL-11, amperage