The performance of carbon steel tees depends mainly on the carbon content and microstructure of the steel. In the annealed or hot rolled state, as the carbon content increases, the strength and hardness of the tee increase, while the ductility and impact toughness decrease, and the weldability and cold bendability deteriorate.
The aging of low carbon steel tees usually has two kinds of quenching aging and strain aging, which are caused by the action of interstitial elements, mainly due to the redistribution of carbon, nitrogen and oxygen.
Carbon steel three-way quenching aging
That is, the performance of carbon steel tee changes with time after rapid cooling at high temperature. The carbon content, deoxidation degree and nitrogen content of steel have great influence on quenching aging. Low carbon steel, insufficient deoxidized boiling steel and high nitrogen content steel have the most significant quenching aging, and the carbon content is about 0.3%. The medium carbon steel, the performance change caused by quenching aging has been greatly weakened, and the high carbon steel containing about 0.6% of carbon does not actually have age hardening effect.