While I haven't played Dark Heresy, this is a very common problem in superhero games (which I do have extensive experience with); Player 1 creates Black Widow and Player 2 creates the Hulk. Any opponent that would challenge the Hulk would smear Black Widow on the sidewalk, making combat balance a nightmare. (There have been attempts in recent years to create supers systems that rectify this, to varying levels of success, but it's still a problem if you allow any kind of flexibility in power selection.)
You keep referring to "the enemy" in your question, which leads me to believe that your GM is doing the extremely common "one bad guy with maybe a few minions" approach to combat, which is extremely hard to balance for precisely the reason above. I've found several methods to be very effective in dealing with this situation.
1. More enemies
Your tank is a killing machine, but he's only one man. Unless his axe is capable of splatting "seven in one blow", he can only murder one (or a small number of) opponent(s) a round - which means that a horde of fifty goblins (or any weak creature that isn't much of a threat to any one of the other party members by themselves) is still a danger to the group as a whole. This allows the other players to contribute by killing enemies as easily as your tank, as well as letting them get into combat with enemies that won't gut them where they stand. (see: the end of the first Avengers movie where the Hulk, Thor, Widow, and Hawkeye are all equally rampaging through the Chitauri mooks.) Sure, your tank may be pretty much invulnerable to these guys, but the failure state of every combat need not be "dead party".
2. More variety of enemies
The "Big Bad with his Mooks" concept fixes the problem in general, but it's not fun. Every fight becomes "the tank gets all the glory of whomping the bad guy while we're stuck on cleanup duty." This can be solved by not having the Big Bad be the only interesting opponent. Again, referencing the Avengers, the Hulk and Thor got to go up against the big flying alien creatures, which were huge and impressive and fun to stomp on but ultimately still just cannon fodder. A variety of opponents of varying skill/power levels allows not only for everyone to have an interesting battle (especially if, as mentioned above, there's enough for everyone), but naturally allows for interesting tactics as the players must figure out how to divide up their skills to effectively go after the enemy. In my old Star Wars game, for example, if one of the bad guys ignited a lightsaber the players would nod to the Jedi in the party and say, "You got this."
Which brings me to...
3. More varied combat goals
Do you remember how, at the end of The Phantom Menace the Jedi fought Darth Maul while Anakin flew against the Federation ship and Amidala led her royal guard to capture the palace while the Gungans fought in the field? This was in part to allow each character to shine in their individual roles (well, except Jar Jar), but also because the goal of the end battle required multiple conditions to be met in order to succeed. Structuring big combats in a way where the end goal isn't simply "thump the villain" goes a long way towards not only making your encounters more interesting, but also allows the GM to balance the challenges for the party in such a way that choosing the right man for each part of the job (as well as the job itself) becomes part of the strategy, and fun. Maybe your tank can hold off the rampaging Destruction Engine while the skill monkey hacks into the mainframe and the diplomancer leads all of the cannon fod- I mean, NPC allies to victory. If planned right it doesn't even require splitting the party, which is usually why such things aren't done. It's a challenge, but I've found players love these kinds of scenarios and find them very rewarding. Also, this usually means that (as I said at the end of Point 1) you're working toward some goal other than simply splatting the bad guy, which allows you to lose the fight without anyone being killed. Every encounter need not be a "win or die" scenario; sure, you didn't take any damage, but you also didn't stop the horde of goblins from kidnapping the princess because five of them snuck away while the other forty of them were suiciding against your awesomeness.
4. Two-pronged attacks
Are there ways for an enemy to be defeated other than being pounded to death? The Hulk may have gone toe to toe with the Abomination, but the Wasp flew into Bommy's ear and effectively bypassed his armor. If the GM comes up with alternate methods for players to affect the combat other than "deal damage/avoid damage", it gives added strategic elements to an encounter (coming up with said alternate methods), and rewards players for thinking outside the box. (This could also be used against you; is there a way for the GM to vary the attacks of the bad guys such that they can bypass your armor such that you're brought down to the same level as your allies? I wouldn't recommend doing this every combat, but shaking it up once in a while would be useful.)
Finally, there's no real reason why you can't simply acknowledge that your dude is better at fighting than the rest of the party, and simply go with it. Are you the best hacker? No, Player Two is. So when there's a computer, do you hack it? No, he does. Subsequently, when there's a Killbot rampaging, does he attack it? No, you do. Different roles.
In closing, I don't think anyone's at fault, and you don't need to cripple your character or do away with him because he's good at things the rest of the group isn't. It's the GM's responsibility to come up with challenges that don't all devolve into "pile on the bad guy until he's dead". Providing a variety of enemies, goals, and methods to win a battle will ensure that everyone has something to do as well as keeping combat fresh in the long run.