【摘要】 研究了二次硬化钢 2 5Cr3Mo3NiNb的冲击韧度随回火温度和试验温度的变化。结果发现 ,试验钢在2 0 0℃回火时冲击韧度较高 ,30 0～ 60 0℃回火时冲击韧度值较低 ,60 0℃以上回火时冲击韧度值迅速升高 ,640℃回火时冲击韧度达到最高值 5 5J/cm2 ,640℃以上回火时冲击韧度值有所降低。 640℃回火后试验钢的冷脆转变温度为 10℃ ,屈服强度为 960MPa ,可以满足兵器特种结构件高强度高韧性的要求。更多还原

【Abstract】 The variations of impact toughness with tempering temperature and test temperature for secondary hardening steel 25Cr3Mo3NiNb were studied.It is found that the experimental steel has a relatively higher impact toughness when tempered at 200℃,then a lower impact toughness at 300～600℃,and a peak impact toughness of 55J/cm2 at 640℃.In addition,when tempered at 640℃,the ductile-brittle transition temperature(DBTT)is about 10℃ and the yield strength reachs to 960MPa.The combination of high strength and impact toughness of the steel makes it suitable for producing some important parts used in ordnance industry.更多还原