In modern world more and more materials with extreme properties are being used: high alloys, high-entropy alloys, nanostructured materials, etc. The extreme properties of these materials make them especially sensitive to hydrogen diffusion. Hydrogen can severely impair their properties and cause failures in structures and machines the material is used in. Nowadays, when structures and components are becoming increasingly complex, the use of 3D printing technology is becoming more widespread. Components made using 3D printing technologies are usually layered, which increase the amount of hydrogen that can diffuse into the material. The amount of hydrogen concentration in 3D printed nickel samples has been determined using vacuum heating method in hydrogen analyzer AV-1. The samples were held at different constant temperatures and the total amount of hydrogen extracted at those temperatures was calculated. A mathematic model was developed to evaluate the amount of hydrogen extracted at a given temperature. The evaluation was then compared to the experiment results, and the validity of the mathematical model and the selected hydrogen activation energies was verified.