摘要
针对具有不同w_(Ti)/w_N的低Al-Ti-B系列和高Al-B试验钢进行末端淬火试验和调质热处理试验,通过淬透性曲线、热力学计算、组织和力学性能的对比分析,研究了w_(Ti)/w_N和Al含量对含B调质钢淬透性及力学性能的影响。结果表明,低Al-Ti-B系列钢的w_(Ti)/w_N大于3.42时,Ti能有效地固N保B提高淬透性,但过高的w_(Ti)/w_N又容易形成粗大的TiN颗粒降低韧性;w_(Ti)/w_N小于3.42时,Ti固N的能力有限,多余的N易与B结合形成BN降低淬透性;试验钢中较合适的w_(Ti)/w_N为3.93,保证了较高的淬透性和综合力学性能。高Al-B钢中较高的Al含量(0.083%,质量分数)起到了固N保B的效果,其淬透性最好,能获得全厚度马氏体组织,具有高的强韧性。此外,钢中过高的N含量易与Ti、B结合形成对淬透性和韧性不利的粗大TiN和BN颗粒,为确保含B调质钢的淬透性和强韧性,应严格控制钢中的N含量。
Jominy test and quenching and tempering heat treatment were carried out on B-containing low-Al-Ti-B and high-Al-B steels.Effects of wTi/wNand Al content on the hardenability and mechanical properties were studied by means of the hardenability curves,thermodynamic calculation,microstructure analyses and mechanical testing.The results show that when wTi/wNin low-Al-Ti-B steels is greater than 3.42,N is fixed effectively by Ti and B is free to improve hardenability,but too high wTi/wN may lead to formation of coarse TiN particles,which is harmful to toughness.When wTi/wNis less than 3.42,the ability of Ti to fix N is limited and the excess N easily combines with B to form BN particles,which is also harmful to toughness.An optimum wTi/wN of 3.93 is found to be favorable for a high hardenability and good mechanical properties.On the other hand,with an Al content（mass fraction）of 0.083%,the high-Al-B steel exhibits the best combination of hardenability and mechanical properties due to the sufficient fixing N effect on Al.In addition,a high level of excess N promotes the formation of coarse particles of TiN and BN which are harmful to hardenability and toughness,and hence N content should be strictly controlled in B-containing steels.
出处
《钢铁研究学报》
CAS
CSCD
北大核心
2016年第2期57-62,共6页
Journal of Iron and Steel Research
关键词
含B调质钢
AL含量
淬透性
力学性能
B-containing quenched-and-tempered steel
Al content
hardenability
mechanical property
作者简介
张娟（1988-），女，硕士，助理研究员；E—mail：zhjuan8889@163.com
