Abstract: The test steel Mn18Cr18N (0.03C, 19.25Cr, 17.96Mn, 0.59N) is melted by an 100 kg pressured vacuum induction furnace, forged breakdown and rolled to 12mm plate. With using Gleeble 3800 thermal simulation machine the effect of temperature (750-1150 ℃) and deformation (15%-60%) on microhardness and structure of high nitrogen steel Mnl8Crl8N is studied to get a recrystallization diagram of the high nitrogen steel. Test results show that in non-crystallization region with increasing temperature at definite strain, the microhardness of high nitrogen steel Mn18Cr18N decreases slowly, but decreases quickly in part-recrystallization region, finally again decreases slowly in complete recrystallization region ； in complete recrystallization region the main strengthening mechanism is grain refining strengthening and the microhardness value and average grain size are in accordance with Hall-Petch experienced formula ； in non-recrystallization region the strain strengthening is major strengthening mechanism ； and the effect of strain strengthening in non-crystallization region is higher than that in recrystallization region.

摘要： 试验用Mn18Cr18N钢(/%:0.03C、19.25Cr、17.96Mn、0.59N)经100 kg加压真空感应炉冶炼,锻造开坯并轧成12 mm板。用Gleeble 3800热模拟机研究了温度(750～1150℃)和变形(15%～60%)对Mn18Cr18N高氮钢显微硬度和组织的影响,并得高氮钢的再结晶图。试验结果显示,处于未再结晶区时高氮钢Mn18Cr18N的显微硬度随着变形温度升高缓慢下降,部分再结晶区时快速下降,完全再结晶区时又缓慢下降;在完全再结晶区时,细晶强化是试验钢主要强化方式,显微硬度与晶粒尺寸符合Hall-Petch经验公式;在未再结晶区时,应变强化是主要强化方式;未再结晶区变形强化效果要明显高于再结晶区。

关键词: 高氮奥氏体不锈钢, 热变形, 显微硬度, 再结晶