Unfortunately that's a property that steel *as used in bicycle frames* does not possess. Sure there are the fatigue curves that flatten out at some very low stress level and hopefully a bike frame is designed so that typical pedaling forces are down around or below that level. But it's simply not practical to build the frame strong enough so that all the forces applied to it in use will not result in stresses beyond the fatigue limit. To ensure that every pothole impact, every all-out sprint, every bunny-hop, etc. stays below that low stress level would require a frame that weighs a few times the normal amount and almost no one would buy it.