Producing a steel alloy that has both high and low temperature capabilities is non-trivial. However, recently a novel maraging steel has been developed that has shown excellent high and low temperature properties. In previous work we have shown how the thermomechanical processing route influences the mechanical properties, and models have been developed to understand the microstructural changes and mechanical behaviour. However, the creep behaviour has proved more difficult to understand. The problem in understanding creep is that accurate quantification of the microstructural changes is difficult and quantification is not possible by other methods. Hence, we want to use SANS to characterise precipitation and void formation to be able to understand and model creep and elevated temperature properties of this alloy.