If they raging at each other, and you witnessing it. Just say something along the lines of "if you guys stop whining we'd have a 23 percent higher chance of winning this game". or if they raging at you, just say something along the line of insulting yourself or taking credit for other peoples mistakes for them, and the ragers rage goes down knowing that they know you didn't hate them for their mistake. they usually insecure, and when they make a mistake they quickly rage at the nearest person cause they feel like the nearest person will rage. so they try to beat them to it, just say sorry if they die or something even before they rage so it calms em. even if it was their fault, take the credit for them, put your ego aside. it is ego's that is the root of alot of rage, and it is ego's that is the root of being hurt by other people's rage. if you got no ego, you are immune to being hurt by someone's rage. their rage just never gets under your skin. the problem is people just care too much about the game, and people need to just take a step back and not take everything so seriously, even ranked games. but still try your darndest to win, but don't expect to win them all or get a good elo. you'd just rage alot if you did, or get hurt by rage alot.
i find it amusing to lose if you just don't get mad, or get mad at people getting mad. losing is inevitable, so might aswell embrace the fact that it will happen and not get mad when it does. keep in mind no matter how bad you are, match making will still try it's darndest to make you win half your games. it's job is to place you in even matches. if you lose alot it just keeps stacking the odds in your favor more and more, until you are winning half your games again. same is true if you are winning alot. the point of me saying this matchmaking bit, is that don't be afraid to play normals just because you are afraid of losing alot. it won't happen, after your first initial losing streak, but after that people will carry you by nature.
one other reason why it is not good to be afraid of ragers, is that they will always be there. and hiding from them, is not going to do any thing to help you. you got to expose your self to it, learn skills to deal with it, test yourself, and always try to focus on letting it NOT get under your skin. try to positively deal with it, in a way that you are making positive changes to peoples attitudes. Nothing wrong with playing bad, or getting unlucky in a game. But the people who rage at you for it are the true wrong doers, who will reap what they sow eventually. Joining them and fighting fire with fire, usually will end up YOU yourself getting upset. for you know that you are just as wrong of a wrong doer as they are, and you let them get the best of you, and you sank to their level.