钢的TTT曲线测定方法研究

Research on Test Method of TTT Diagram of Steel

选取了一种轧辊用钢作为试验用钢,测定了它的TTT曲线,然后选择750℃、725℃、700℃和675℃四个温度,在与等温转变过程相同的试验条件下分别进行DSC分析和高温XRD残余奥氏体含量分析,然后将试验结果进行比较。研究表明,与膨胀法相比,DSC法测定的组织转变开始和结束时间较早;与杠杆法相比,在同一时间,高温XRD分析法测定的组织转变量较大。因此,采用膨胀法和杠杆法测定TTT曲线还需结合DSC分析法和高温XRD分析法,方可精确测定钢的TTT曲线。

A steel that used for making rollers has been chosen for test and its TTT diagram has been measured.DSC analysis and XRD analysis of retained austenite content have been separately performed under test condition as same as the isothermal transformation process at temperature 750℃,725℃,700℃ and 675℃,and then we have the test results compared. The research shows that comparing to expansion method,both the start and the finish of structural transformation are earlier by DSC method. As comparing to the lever method,during the same period of time,the quantity of structural transformation was determined larger by high-temperature XRD method. Therefore,it is necessary to combine DSC analysis method and XRD high-temperature method to determine TTT diagram by expansion method and lever method.