BH08G焊接用钢的热变形行为及动力学再结晶模型

用Gleeble-1500热模拟试验机研究了成分(% )为。.08C、l. 59Mn、0.34Mo、0.12Ti的BH08G焊接用 钢在950 ~ 1050℃ 、变形速率 ε 为0.1 ~ 10.0 s ^-1时的热变形行为。通过奥氏体再结晶动力学回归计算得出： BH08G钢的Zener-Hollomon参数Z与峰值应力的关系式为Z =3. 829 x 10¹²exp(0.046 46 δ_m); 峰值应力 δ_m、动态再结晶临界应变ε_c、峰值应变ε_m、动态再结晶完成应变ε_s与InZ的关系为:δ_m=21.338InZ-516.49,ε_c≈ 0.83ε_m= 0.032 6InZ-0.732, ε_s=0.052 2InZ -0.980 1 。通过BH08G钢动态再结晶状态图得出,BH08G钢粗轧温度为980 ~ 1 050 ℃、精轧温度为930 -980℃有利于变形晶粒细化，改善材料的力学性能。

Thermal Deformation Behavior and Dynamic Recrystallization Model of BH08G Welded Steel

The thermal deformation behavior of BH08G welded steel- 0.08C, 1.59Mn, 0. 34Mo, 0.1215 with strain rate ε 0.1~10.0 s^-1 at 950 ~ 1 050℃ has been studied by Gleeble-1500 thermal simulation machine. It is obtained by regression calculation of austenite recrystallization dynamics that relation between Zener-Hollomon parameter Z and peak stress δ_m is Z = 3. 829 x 10¹² exp (0.046 46δ_m) , and relation of lnZ with peak stress δ_m, dynamic recrystallization critical strain ε_m, peak strain ε_m , and dynamic recrystallization finishing strain ε_s is respectively δ_m= 21. 338 InZ - 516.49, ε_{c ≈} 0. 83ε_m= 0.032 6 InZ - 0.732, and ε_s, = 0.052 2 InZ -0.980 1. The dynamic recrystallization state diagram of BH08G steel shows that with rough rolling at 980 ~ 105 0℃ and finishing rolling at 930 ~ 980℃ it is available to fine deformed grain and improve mechanical properties of material.