Looking through the _http_client.js code it seems to me that the http.ClientRequest object never emits an ´aborted´ event (only close). It's just the response object that emits the aborted event.
https://github.com/nodejs/node/blob/master/lib/_http_client.js#L366
That seems to go against the docs, https://nodejs.org/api/http.html#http_event_aborted