Heat-affected zones (HAZs) in real welds are usually quite narrow, and consequently most standard mechanical tests are difficult or even impossible. Therefore, simulated microstructures are often used for mechanical tests. However, the most often used weld thermal cycle simulator produces only a few millimeters wide area of simulated microstructure in the middle of specimens. Consequently, these kind of simulated specimen are not suitable for standard tensile tests, and even for Charpy impact tests, the simulated area can be too narrow. Therefore, to investigate the mechanical properties of a fine-grain heat-affected zone in 18CrNiMo7-6 steel, two methods were used for simulation of as-welded microstructures: (a) a weld thermal cycle simulator, and (b) as an alternative, though not yet verified option, austenitizing in a laboratory furnace + water quenching. The microstructures were compared and mechanical properties investigated. The grain sizes of the simulated specimens were 10.9 μm (water-quenched) and 12.6 μm (simulator), whereby the deviations from the real weld were less than 10%. Both types of simulated specimen were used for hardness measurement, Charpy impact tests, and fatigue tests. Water-quenched specimens were large enough to enable standard tensile testing. A hardness of 425 HV, yield strength Rp02 = 1121 MPa, tensile strength Rm = 1475 MPa, impact energy KV = 73.11 J, and crack propagation threshold ΔKthR = 4.33 MPa m0.5 were obtained with the water quenched specimens, and 419 HV, KV = 101.49 J, and ΔKthR = 3.4 MPa m0.5 with the specimens prepared with the simulator. Comparison of the results confirmed that the annealed and quenched specimens were suitable for mechanical tests of FG HAZs, even for standard tensile tests. Due to the use of simulated test specimens, the mechanical properties determined can be linked to the FG HAZ microstructure in 18CrNiMo7-6 steel.

A hot-rolled clad plate made of 316L stainless steel and S355 carbon steel was produced in a real industrial environment via GMAW welding, vacuuming, preheating to 1240 °C, and hot-roll bonding on four stand plate mills in nine passes with reduction rates between 22–26% per pass. The clad plates were solution annealed to achieve the usual delivery condition. Ultrasound testing showed a bonding rate of 100%. Metallographic examination revealed predominantly low concentrations of oxides at the interface. The tensile strength of the bond reached 155 MPa. The shear strength always satisfied the requirements of ASTM A264. It was observed that the concentration of oxide particles influenced the shear strength strongly. The lowest measured value was 172 MPa. Specimens notched in the base material and specimens notched in the clad layer were used in the Charpy impact test. In every case, only the notched layer broke, while the other layer was only bent. The absorbed energies were always higher than those of each material alone. Fracture mechanic tests gave similar results. The crack could not propagate from the notched layer into the other one, regardless of the material of the notched layer. Instead, delamination occurred. Due to delamination, K1c could not be determined, so KQ was given instead.

Weld cladding or weld overlay is a frequently used method for repair welding of damaged surfaces and for production of different surface coatings. The conventional coated electrodes have a circular cross-section. In order to increase the productivity and to decrease dilution and the depth of the heat affected zone (HAZ), the geometry of the electrode core was modified. Experimental weld cladding was carried out with rutile coated electrodes of rectangular cross-sections of 12.56×1 mm2, and for reference, also with a conventional φ 4 mm electrode Rutilen 2000 S. The coating of rectangular electrodes was identical and the core material almost identical to the materials of the standard electrode. The base material was the structural steel 355JR. The goal of investigation was to determine the welding parameters for the rectangular electrodes and to compare geometries and mechanical properties of the welds. Hardness and the dimensions of weld metal and HAZ were measured. Results with the 6.28×2 mm 2 and 6.28×2 mm electrode were similar to the results with the standard electrode. However, with the 12.56×1 mm2 rectangular electrode, significantly lower currents were sufficient to obtain a good quality of the deposition layer. Due to possibility to weld with currents as low as 80-100 A, shallower and smaller HAZs and less dilution can be achieved with the rectangular 12.56×1 mm2 electrode than with standard cylindrical φ 4 mm electrode.

The high-strength low-alloy steel S1100QL is used in the most demanding mechanical engineering applications. Typical structures made of this steel are hydraulically extendable pallet cranes in mobile lifting machinery, which require high strength-to-weight ratio. The high yield strength and toughness of S1100QL steel is achieved through proper chemical composition, hot rolling, and heat treatment. Those factors also have a strong effect on the weldability of this steel: the welded joint should have the properties required by EN ISO 15614-1. In this paper, the main properties of the S1100QL steel are shown. In addition, WPQR was performed on a 15 mm thick plate using the GMAW process. Analysed properties such as tensile test, impact toughness, hardness and microstructure are compared to the requirements of the international standards from the field of arc welding.

MIG / MAG welding with solid or flux cored welding wire and TIG welding are most important arc processes for industrial application. In last period, laser welding become more and more important in industrial welding and cladding applications. Optimum selection of welding process for specific application include more important parameters like productivity, demand quality of weld and influence of welding process to health of welder. With shielding gases is possible to influence on productivity, and quantity of welding fumes. Some welding shielding gases include nitrogen.