make a new file, use the clouds filter (filter -> render -> clouds) (just make sure that your back and foreground color are black and white).

adjust the brightness/contract (image -> adjust -> brightness/contrast) so that the image looks similar to pic1.

make a new layer and fill it with white. add some monocromatic noise (filter -> noise -> add noise) (about 50). use the motion blur filter (filter -> blur -> motion blur) in horicontal direction with an intensity of 30. now go to the layer options and choose multiply.

now for the rust: duplicate the layer, add some noise (50 or so) and emboss the whole thing (filter -> stylize -> emboss) play aroud with the settings. i used 138°, 2 pixel height and an ammout of 152%. now use the hue/saturation (strg+u) to colorize the whole thing in a decent yellow / brown tone (depends on which rust you want to have).

now add a layer mask on the rusty layer and apply clouds in the layer mask.use brightness/contrast to sharpen the mask.

the rust was a bit too light for me, and so i changed the layer options to multiply, and added another layer with the rusty texture and a different cloud mask.

note that this is only one alternative to make metal and rust, there are various others out there, some are a bit easier, but i tend to use this alternative. for exact rust positioning don't use clouds in the layer mask, just use the airbrush tool to paint the rust where you want it.