盾构机轴承套圈用钢42CrMo连续加热奥氏体晶粒长大模型

Model of Austenite Grain Growth during a Continuous Heating Process of Steel 42CrMo for Bearing Ring of Shield Tunneling Machine

基于盾构机轴承套圈用42CrMo钢的等温奥氏体长大模型,并利用相加性原则,建立了该钢在连续加热过程中的奥氏体晶粒长大模型.该建立的模型考虑了原始奥氏体晶粒尺寸的影响,包括建立的在间隔时间（ti-1,ti）内晶粒尺寸di模型以及保温时间ti＊模型.通过Gleeble-1500试验机,测试了42CrMo钢（/％：0.40C,0.23Si,0.60Mn,0.016P,0.001S,1.08Cr,0.22Mo）锻坯（终锻温度850℃）以100℃/s加热1000～1300℃,水冷后的奥氏体晶粒尺寸.结果表明,奥氏体化温度由1000℃增加至1 100℃时,42CrMo钢奥氏体晶粒尺寸由16.3 μm增至30.3 μm;加热温度超过1 100℃,晶粒尺寸急剧增加,1300℃时,奥氏体晶粒尺寸为112.5 μm;奥氏体晶粒尺寸的模型预测值与实测值吻合较好.

Based on the model of isothermal austenite grain growth of steel 42CrMo for bearing ring of shield tunneling machine, the model of austenite grain growth during continuous heating process of steel has been established by using the principle of additivity. The effect of original austenite grain size is considered in the established model, it is included in es- tablished models of grain size dj and soaking time ti ＊ during interval time （ti_l, ti）. With using Gleeble-1500 thermal simulation machine the austenite grain size of forged billet （finishing forging at 850℃ ） of steel 42CrMo （/% ： 0. 40C, 0. 23Si, 0. 60Mn, 0. 016P, 0. O01S, 1.08Cr, 0. 22Mo） with 100℃/s heated to 1 000 - 1 300℃ and water cooling has been tested and measured. Results show that with increasing austenitizing temperature from 1000 ℃ to 1 100 ℃the grain size of austenite in steel 42CrMo increases from 16.3 μm to 30. 3 μm, the grain size of steel rapidly increases as heating temperature is more than 1 100℃ and the austenite grain size in steel heating at 1 300 ℃ is 112. 5 μm; the predicted value by model and measured value of austenite grain size in steel are better identical.