No matter how hard the landing, the struts can only compress so far -- beyond that the energy has to go somewhere else. I guess other things, for example the wings, would then flex, and to some extent they would flex back and cycle the struts again. But it seems hard to imagine a vastly greater amount of energy going into the struts on a hard landing than on just a firm one.
Oh, and on plain steel it takes 575 degrees F (about 300 C) to get a blue temper. But it might well be significantly higher on chrome plate.