Abstract: The effect of different carbon, chromium and molybdenum contents on mechanical properties of six kinds of cold heading steels (/% ：0.19C,0.36C,0.19C-0.96Cr,0.39C-0.98Cr,0.19C-0.91Cr-0.21Mo and 0.37C-0.98Cr- 0.22Mo) at 650 ~ 1200℃had been studied by using GLEEBLE-3500 thermal simulation machine. Results reveal that： the third brittle region of all of the steels is obvious in the temperature range 650 ~ 850 ℃.The starting temperature of the third brittle region moves to higher temperature with the carbon content decreasing or chromium element adding. Addition of chromium deteriorates the ductility and promotes the third brittle region expanding. Addition of molybdenum in the chromium alloyed cold heading steels improves the ductility of the third brittle region.

摘要： 通过GLEEBLE-3500热模拟机,研究了六种不同碳、铬和钼含量对冷镦钢(/%:0.19C,0.36C,0.19C-0.96Cr,0.39C-0.98Cr,0.19C-0.91Cr-0.21Mo和0.37C-0.98Cr-0.22Mo)在650～1200℃温度内的高温力学性能的影响。结果表明,六种钢在650～850℃温度都存在明显的第Ⅲ脆性区。第Ⅲ脆性区的起始温度随着碳含量减少和铬含量的添加移向更高温度。铬的添加使得材料的高温塑性恶化,促进第Ⅲ脆性区扩大。而钼的添加可改善含铬冷镦钢的第Ⅲ脆性区塑性。

关键词: C , Cr , Mo, 冷镦钢, 高温力学性能