高碳钢球化机制与Ac_(1f)透烧球化退火工艺

Spheroidizing Mechanism and Ac_(1f) Temperature Equalization Spheroidizing Annealing Technology for High-carbon Steel

对高碳钢球化退火机制进行了研究 ,认为碳化物球化的核心是加热时的剩余碳化物 ,若加热时得到不均匀奥氏体和剩余碳化物组织 ,则奥氏体过冷分解是α相在碳化物质点间单独形核 ,随后两相以幂函数规律各自独立呈球状急速长大成粒状珠光体 (PS)组织 ;当加热得到均匀奥氏体和剩余碳化物时 ,过冷奥氏体的分解按两相相互激发形核及随后的合作、协调、匹配长大成层片状珠光体 (PL)。由此开发出Ac1f透烧加热的球化退火工艺 ,生产试验取得了球化质量好、生产周期短及节能的效果。

The mechanism of spheroidizing annealing for high-carbon steel was studied.The residual carbide was considered as nuclei of granular carbide in heating.When inhomogeneous austenite and residual carbide are obtained during heating,α phase nucleates individually between carbide particles during overcooling decomposition of austenite,then the two phases grow into spheroidal grains respectively in power function rule,and spheroidal pearlite (P S) is obtained.If homogenous austenite and residual carbide are obtained during heating,the overcooling austenite decomposed into lamellar pearlite (P L) in inter-excited nucleation,then growth through cooperation,coordination and matching of the two phases.Thus,Ac 1f temperature equalization spheroidizing annealing technique is developed,which acquired good spheroidizing quality,shortened productive cycle and saved energy in production test.