摘要
21 4N(5Cr2 1Mn9Ni4N)钢为汽车发动机排气阀用奥氏体耐热钢 ,该钢主要通过碳、氮化物沉淀硬化 ,在 70 0℃使用温度下具有高的强韧性和耐磨性 ,并具有冷热交变的组织稳定性和抗氧化性 ,广泛用于制造排气阀。由于 2 1 4N钢的热变形温度范围窄 ,该钢最佳锻轧温度为 110 0～ 980℃ ,冷加工硬化效应强 ,变形抗力较 1Cr18Ni9Ti钢高 30 % ,在锻造、热轧、冷拔时易产生裂纹。冷拔时两道次变形量≤ 1 10 ,钢中冷轧代替冷拔 ,加入提高钢的热塑性的稀土等微量元素和控制工艺参数是降低钢材表面裂纹。
The steel 21-4N (5Cr21Mn9Ni4N) is an austenite heat resistant steel for exhaust valve of automobile engine, it has high strength, toughness and wear resistance by carbo-nitride precipitation hardening, and has structure stability with temperature change and oxidation-resistance at service temperature 700 ℃. The steel is widely used to manufacture exhaust valve. Due to narrow hot deformation temperature range of steel 21-4N and easily occurred crack during forging, rolling and cold drawing , the optimum forging and rolling temperature of steel is between 1 100 ℃ and 980 ℃. The steel 21-4N has strong cold work hardening effect, its deformation resistance is higher than steel 1Cr18Ni9Ti by 30%, so the reduction in two pass cold drawing is ≤1.10, cold rolling to replace cold drawing, adding rare earth elements in steel to increase hot plasticity of steel and exactly controlling process are main measures to decrease surface crack of steel products and increase yield.
出处
《特殊钢》
北大核心
2004年第5期30-33,共4页
Special Steel
基金
20 0 3国家火炬计划项目 (批准号 :2 0 0 3EB0 30 4 0 8)
