## 7 Results and Discussion  
This study shows how the risk-based qualification approach can be implemented into the qualification of additively manufactured parts. For this aim, an example qualification for a nozzle component fabricated using AM is presented. Previously, this type of nozzles is used for downhole cleanouts of oil and gas wellbores using the combination of traditional machining and an extra wire cut working. Before the introduction of AM, the only alternative was to fabricate these components by assembling several smaller parts. However, Norway's EnergyX recently succeeded in producing this type of nozzle using AM, which helps enhancement of the integrity of the nozzle and also reduces the costs [44]. Figure 4 shows the nozzle assembled to the intended location in pipe work. This type of nozzle can be made of carbon steel, stainless steel or Inconel grades. However, for the aim of this work, the nozzle is considered for application in mild sour service and based on engineering best practices, the stainless steel nozzle is a good choice for this type of fluid service. Table 7 indicates a list of active damage mechanisms of additively manufactured stainless steel nozzles in downhole applications. As is obvious from Table 7, the additively manufactured components may have lower fatigue strength than the wrought stainless steel and therefore, the additively manufactured nozzle should be examined with a fatigue test before the application. This type of inspection may not be required for wrought components. Figure 3: Risk-based qualification process. Table 8 indicates the results of the risk-based qualification process for this additively manufactured stainless steel nozzle. In this qualification process, a three-level risk matrix (Figure 5) is used and inspection plans are categorized into three classes, including A, B, and C. The class \"A\" obtains more accurate inspection but is costly. Then this class should be used for the inspection of high-risk components. The risk of components is identified based on Figure 5.  
According to the \"scope\" column in Table 6, for high-risk components, the number of required tests is also high. A high number of tests increases the confidence in the procedure; however, in a mean time it increases the inspection costs. In addition, according to this table, there is no need to use costly methods such as SSC/HIC tests and CT-scan for low-risk components such as components used in the vent section of the plant. As is clear from Table 8, if an AM system is used for the production of this stainless-steel nozzle component for downhole cleanout applications, the chemical and metallurgical characteristics of the feed powder, process parameters, metallurgical, and corrosion tests of the final samples, non-destructive inspection of the produced samples are the most quality-affecting parameters. It means that these parameters should be controlled using much stricter measures, e.g., by using advanced NDE methods for all samples. However, for qualification stands with the medium risk category, the medium level evaluation methods for two-thirds of the samples are suggested. Random inspection using less developed methods for low-risk qualification items can be acceptable.