There’s a conflict brewing in “Avengers: Age of Ultron,” and it doesn’t involve megalomaniac robots. After reaching a peace with their structure and roles on the superhero fighting team, Tony Stark/Iron Man and Steve Rogers/Captain America have begun to clash ideologically. 

The stoic Steve, still reeling from revelations of widespread corruption in “The Winter Soldier,” is starting to question the precepts he’s followed blindly for so long. Tony, meanwhile, is drifting toward the desire for order and control. 

“Morality hits Tony, humanity hits Tony. All of a sudden he feels responsible,” said Chris Evans, who plays Rogers for the fourth time in the billion-dollar Marvel franchise.

“Neither one of them are blindly convicted. It’s blurry and that’s what makes it great. No one’s right, no one’s wrong,” Evans said in a recent joint interview with Robert Downey Jr., back for a fifth turn as Stark.

“It’s going to make it even harder for them to come to an agreement, which I’m really excited about,” Downey said.

While the seeds of a fight are scattered throughout “Ultron,” the second gathering of the “Avengers,” it’s also setting the stage for next year’s “Captain America: Civil War.” Plot details are sparse, but any casual comics fan knows that “Civil War” is where the “Avengers” fracture, divided down lines set by Tony and Steve.

It’s also the only upcoming Marvel film for which Downey and Evans have been confirmed. 

“It’s like a marriage,” Evans said. “We love each other but it’s explosive. You’re working toward the same goal but you have very different approaches to it.” 

Added Downey: “I’m really stoked to see when we have more stuff to actually do together besides like act like we’re about to have a fight one day.”

Off-screen, the dynamic is, of course, a bit more polite. Sitting on a patio at the Walt Disney Studios in Burbank, Downey and Evans were calm and casual with each other.

When Evans tried to explain how others on set are more talented and smarter than he is, Downey quickly jumped in to offer some reassurance.

“I have stood toe to toe with some of the greatest folks of all time and if Spencer Tracy is right — you know, hit your mark and tell the truth — nobody that I’ve worked with does it the way that (Evans does),” Downey said.

“God. I tinkled a little bit,” laughed Evans in response.

As with the rest of the “Avengers” actors, Evans is downright deferential in the presence of Downey. He made sure to immediately stress Downey’s essential contributions to creating Marvel’s Avenger world. In 2008, the success of “Iron Man” laid the foundation for what is now one of the most influential series in the industry.

“None of this would have happened without Downey,” said Evans, who went on to compare him to “The Godfather.” 

“Success has many masters. It’s fun taking all the credit, but the only part of it that’s true is that I put points on the board for a team that didn’t even know it was going to be a team,” Downey said.

“Ultron” isn’t even in domestic theaters yet, but pre-production is already underway on a summer shoot for “Civil War,” with “Winter Soldier” directors Joe and Anthony Russo at the helm. In the big business of the Marvel Cinematic Universe, there’s no waiting to see how “Ultron” performs before greenlighting future projects.

Both “The Avengers” and “Iron Man 3” made more than $1 billion at the global box office. And, since Disney came on to produce the films, none have made under $600 million worldwide. With a slate that extends through 2019, the studios are betting hard on the continued appeal and evolution of Marvel’s universe.

“Some people say there’s going to be superhero exhaustion. But these movies aren’t just superhero movies,” Evans said. “The superhero involvement is what’s going to bring the audiences because of the familiar properties but then you get into the movie and it’s not just him and his suit, it’s not just me and my shield. It’s people having real life discussions and real life conflicts as characters, that’s what people are going to relate to.” 

Downey agreed, but with a provision. 

“What will happen is it will change,” he said. “I’m just stoked that we get to be still doing this at the point where it’s representative of what it is. It kind of drives the industry.”