摘要
差压铸造ZL201A合金某壳体铸件探伤时,发现部分铸件上存在"白色裂纹"状偏析组织,经取样观察并采用能谱分析、X射线衍射等检测手段对其进行了成分分析,结果表明,在铸件中偏析的主要元素为Cu和Ti。由于在薄厚交替处的补缩存在困难,热应力较大,所以易产生偏析等铸造缺陷;"白色裂纹"状偏析处聚集的合金是Cu,而Ti的熔点较高,在熔炼过程中由于搅拌不均匀等工艺问题,导致了在合金内部存在Ti的显微聚集区,也是造成偏析的另一原因。应该从熔炼和浇注两方面着手,如使用质量较好的中间合金,减少回炉料的用量,加强搅拌,适当提高浇注温度并改善浇注系统的退让性等,可防止此类缺陷的生成。
There exists white-crack segregation in partly differential pressure casting ZL201 Aalloy housings.Microstructure of the housing with white-crack segregation was observed,and chemical composition was examined by EDS(energy dispersive spectrometer) and XRD(X-ray diffraction).The results reveal that segregation in the housing mainly contains Cu and Ti.The creation of segregation is attributed to difficulty in feeding at thin-thick transition location resulting in the larger thermal stress.White-crack segregation is mainly contained Cu element.Meanwhile,there exists Ti segregation zone in some location of alloy as a result of heterogeneous stirring during melting process,which is responsible for the generation of segregation too.Through improving melting process and controlling pouring process,the segregation can be effectively eliminated,including using desirable master alloy,reducing the usage of recycled alloy,strengthening stirring and rationally increasing pouring temperature as well as improving gating system.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2010年第11期1022-1025,共4页
Special Casting & Nonferrous Alloys
