Not even remotely plausible. It looks more like something out of the game Bioshock than it resembles actual Russian posters. And what would the point of this 'propaganda' even be? The Soviet Union did not have Iron Giant-style humanoid robots and didn't need to convince anyone robots were their comrades. Actual pro-industrialization posters looked quite in tone, besides the style.

Also "Камрады сталь" (kamrady stal) is simply incorrect Russian. First, the word kamrad is archaic in Russian and not the term Russian Communists used for 'comrade'. They called eachother товарищ (tovarishch). Second the word сталь is 'steel' as a nominative singular noun. It's not the adjective form you want to say something is made of steel. In English 'steel' is both the adjective and noun but Russian сталь is not. (so probably a bad translation by an English speaker) "Steel comrades" would rather be something like товарищи стальные.

No. As evidenced from the term 'камрады' which is a modern anglicism based on the word 'comrade' not used in the communist era, as well as the entire expression that makes little sense in the alleged Russian, this poster is a modern work of art, In this case, it has been created by a Canadian artist Zachary Mallett (the symbol in the lower right corner is his monogram) and first presented in early 2010s. It might have been inspired by similar retro-futurist works of Zoran Cardula, Macedonian artist who often uses propaganda posters and brutalist architecture of the communist era as his source of inspiration.