It could be a number of things. It could be that the quench was too slow(ideally less than 5s from orange to room temp), which would result in a softer steel where further tempering would yield no changes in hardness. If you are worried about it try annealing and tempering at lower temps, which may lead to quicker quenching. For the initial heat it is only necessary to heat the ejector above around 800 C (grey), but it doesn't hurt to heat up to higher temps, personally I wouldn't go above about 1000 C(orange). As far as tempering, try heating to around 300-500 C(brown/purple) , much higher than that may make you loose some hardness gained from quenching.
Last edited by Yemff; 12-27-2012 at 9:51 AM..