Do you have anything to back up this statement?
Is it controversial? I worked in the plant that built them (Convair in Ft. Worth, TX). Admittedly after they were out of production, but I have stood inside the giant autoclave that was used to braze the SS honeycomb to the SS skin. And I heard countless B-58 (and B-36) stories from the older employees, you may not want to get me started, haha.
A design parameter for the Hustler, which can be viewed as essentially a 4-engine fighter plane, lol, was sustained supersonic flight on the deck = zero feet ASL. What you get from that is extreme skin heating and big-time vibration. Aluminum was a non-optimum choice due to low melting point and high probability of fatigue. At that point in technology, without so many exotic alloy choices and
particularly without titanium being readily available, the practical though costly solution was stainless steel. Don't ask me what alloy because I don't remember. This must have produced the exact
opposite of a stealthy radar signature, but nobody was worrying about that at that time and for that mission.
At the time, if you wanted to set world speed records, the choice was easy: if you're going low, hop in a B-58. If you prefer the high altitudes, call up the friendly neighborhood SR-71.
This construction was not unique in the industry, the Soviets arrived at the same conclusion and one of the super-fast Cold War MIGs, I think the Foxbat but not sure, is also a steel airplane.
I have not attempted to search the web for B-58 info, but I assume standard sources like Janes or contemporary issues of "Aviation Week and Space Technology" would confirm what I am saying if you feel the need.