Ensuring Strength in Laser Welds Made Using the Dispersion-Hardened EP693 Nickel Alloy

The process of making a weld using the heat-resistant EP693 alloy (Ni–Cr–W–Co–Co–Mo system) to make assemblies and components for gas-turbine engines (GTEs) is considered based on laser welding using a TruLaser Cell 7020 CO2 installation operating in the pulse-periodic radiation mode. EP367 (Ni–Mo–Cr–Mn) additive wire is used to obtain the weld. The effect of thermal treating is studied to estimate the change in structure and properties both in the weld-adjacent area and in the weld. The results are used to examine the structure of the weld and its breaks. The physics and mechanical properties of the weld are evaluated. The greatest durability limit is estimated for welds at a level of 2 × 106 cycles. The feasibility of using a laser-welding heat-resistant dispersion hardened nickel alloy is evaluated to make support and stator shells for GTEs. It is established that complex thermal treatment (quenching and aging) provides for the optimum values of strength at room temperature and at high temperatures. It is also responsible for the short-term strength of welds. According to the strength calculations made for the support and stator of GTE shells and experimental data, the strength of welds made using pulse-periodic laser welding results in a strength safety factor between 1.35 and 3. This technology is proposed for industrial application to make shell parts and assemblies to be used in GTE support and stator in order to improve the quality of welds with a reducing time of high-temperature heating to bring down power consumption.