How can I create a procedural cast iron shader similar to these photos?

Question

I want to recreate the cast iron material you can see in the reference images. I'm especially interested in the structure and reflectance properties. The first two images were taken up close and the other two images from further away. I'd like to use a procedural texture because I will render images from up close, the geometry of my model is complex and I want to avoid wrapping artifacts and because I would like to be able to vary the 'bumpiness' a bit between different renders.

Since I'm new to Blender I tried to use tutorials for procedural metal shaders as a starting point and go from there, but I just wasn't able to achieve the correct structure.

Answer 1

I think you can get what you want with just some Noise Textures, mixed together and added as the basis for a Bump Node. The MixRGB right before the Bump (mixing with white) is just there to soften the influence (raw values are often too strong). Don't forget to set Metallic to 1 and lower the Roughness.