How to control and use of mild steel packing strip age hardening phenomenon?

How to control and use of mild steel packing strip age hardening phenomenon? Three times in a low carbon steel in normal after annealing, cementite and nitrides from & alpha; Solid solution in the precipitation, then with ferrite as the base substrate can be heated to Fe - C above phase diagram of the PQ, single-phase ferritic organization after heat preservation, and then quenching, due to induce martensitic phase transformation in the ferritic not, reason or ferrite substrates at room temperature. Then at room temperature by natural aging or heated to 100 - for a long time 120 ℃ artificial aging, this time the original carbon? And nitrogen atoms will be precipitated from ferrite partial poly mesh in space or dislocation. At the same time, the e - Carbide and e - Nitrogen in the form of coherent precipitate? The increased strength and hardness of the material and plastic, toughness drops, a yield platform ( Also called age hardening) 。 For low carbon steel stamping age hardening steel can make sex can deteriorate, slip line or surface wrinkles, and orange peel. So low carbon steel plate should be rapid cooling after annealing, below the line PQ suppression three cementite and nitride precipitation. Low carbon and carbon-free maraging steel, which is through the supersaturated solid solution strengthening and age hardening process, Mn, Mo, Nb, Ti, A1 elements in the form of carbonitride precipitation during aging and implementation to strengthen. They are in the condition of quenching hardness of about 30 HRC, can undertake machining, then at about 450 ℃ ageing 3 - 4 h, to improve tensile strength by 1 Three times, meet the required performance.