Chemical properties of quenched and tempered steel

Quenched and tempered steel carbon content is between 0. 27 ~ 0. 50%. The commonly used carbon quenched and tempered steel, the carbon content is close to the ceiling, 40, 45, 50 such as steel, etc. ; The alloy quenched and tempered steel is match close to lower limit, such as 40 cr, 30 crmnti steel, etc. Alloy quenched and tempered steel containing Cr, Ni, Mn, Ti alloy elements, such as its main role is steel hardenability, progress and tempering after quenched and tempered sorbite strengthen the organization. In the quenched and tempered steel can strengthen the ferrite content of alloy element without significantly reduce its toughness, so that some could progress at the same time its toughness. In the quenched and tempered steel alloy element such as Mo, V, Al, B, its content in general is less, especially the content of B. Mo's main role is to avoid alloy quenched and tempered steel in high temperature tempering to produce category ii this brittle; The function of V is barrier high temperature austenitic grain growth; Is the main purpose of Al alloy quenched and tempered steel can accelerate the nitriding process; Trace amounts of B can strongly the isothermal transformation curve move to the right, remarkable progress alloy quenched and tempered steel's hardenability.