摘要
研究了稀土、钒、钛变质剂对等温淬火高硅铸钢晶粒细化的影响。结果表明,经稀土、钒、钛变质处理后,高硅铸钢中形成大量的高熔点化合物,可以强烈地促进非均质形核,细化高硅铸钢的奥氏体晶粒;同时变质剂的加入可以明显提高钢液的过冷度,促进形核、细化奥氏体晶粒。高硅铸钢等温淬火组织中由一次结晶形成的树枝晶已经完全消除,全部转变为等轴晶;385℃等温时高硅铸钢淬火组织中的块状残余奥氏体的量明显减少,由未变质前的31.9%降低到5.5%,块状残余奥氏体的尺寸也明显减小。
The effects of RE, V and Ti modification on the grain refinement of high silicon cast steels (HSCS) were investigated systematically. The experiment results show that a large a mount of compounds with high-melting point is formed in HSCS after modification. Those high-melting point compounds are very effective in prompting heterogeneous nucleation of austenite and refining the austenite grain of HSCS. At the same time, the addition of modifier increases the degree of supercooling of the steel prompting nucleation of austenite and refining the grains. By modification, the dendrite grain turns into the equiaxed grain after austempering heat treatments. The volume fraction of blocky retained austenite of HSCS decreases remarkably from 31. 9% without modification to 5. 5% after RE/V/Ti multi-modification, and the size of blocky retained austenite also decreases.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2006年第3期75-80,共6页
Transactions of Materials and Heat Treatment
基金
清华大学实验室开放基金(092701123)
关键词
变质
稀土元素
晶粒细化
等温淬火
高硅
铸钢
Austenite
Heat treatment
Melting
Modification
Nucleation
Rare earth elements
Refining
Supercooling
Titanium
Vanadium
Volume fraction
