Manoir Industries developed in the 60’s and 80’s the Manofort® alloys family for the defense industry, for example to equip tanks. The need was a really high strength, around 1000 MPa (ultimate tensile strength) and good impact properties, even at freezing temperatures. Qualification tests were done by real shooting on test sheets. The challenge was that strength and impact properties usually go in opposite ways.
Still, those properties could be achieved by designing new low alloy steels with two essential specificities. First, the chemical composition (they are called low alloy steels but have actually relatively high content of alloying elements compared to standard steels). A typical composition would be: 0,2 wt.%C; 1 wt.%Mn; 2-3 wt.%Ni; 1-2 wt.%Cr; 0,5 wt.%Mo. Second, specificity is that a minimum 5 steps tailored and very precise heat treatment is required to reach those properties.
These grades family then show the best compromise in strength and fracture toughness/impact test properties among any conventional material. Today, Manoir still supplies parts in these alloys for the defense industry.