摘要
为了得到塑性性能优良的锡青铜QSn7-0.2连杆衬套旋压毛坯,现以锡青铜QSn7-0.2连杆衬套材料为研究对象,在640~760 ℃的温度范围内对其进行反挤压试验.通过OM、SEM和拉伸等实验方法,研究挤压温度对其微观组织和性能的影响.研究结果表明：随着挤压温度的升高,在720 ℃时锡青铜QSn7-0.2材料的伸长率和断面收缩率达到最高.根据对金相组织的分析表明,随着挤压温度的升高,晶粒尺寸逐渐增大,当温度超过720 ℃后,晶粒有加速长大的趋势.根据对断口的分析表明,锡青铜QSn7-0.2材料在较低温度挤压成形时,拉伸断口处存在较多解理断裂面,随着挤压温度的升高,拉伸断口处解理面逐渐减少.综上可得,锡青铜QSn7-0.2材料在720 ℃时挤压成形得到的塑性最好.
In order to get the spinning billet of connecting rod bushing of tin bronze QSn7-0.2 with good plastic performance,the connect-ing rod bushing material of tin bronze QSn7-0.2 was regarded as research object,and the anti-extrusion test at 640-760 ℃ was conduc-ted. Then,the influences of extrusion temperature on its microstructures and properties were studied by OM, SEM and tensile test. The results show that with the increasing of extrusion temperature,the elongation and reduction of cross section for tin bronze QSn7-0.2 materi-al reach the highest at 720℃. According to the analysis of metallographic structure,the grain size increases gradually with the increasing of extrusion temperature. When the temperature exceeds 720 ℃,the grain has the tendency to accelerate growth. According to the analy-sis of fracture,when the tin bronze QSn7-0.2 material is extruded at lower temperature,more cleavage fracture surfaces exist in the tensile fracture,and the cleavage surfaces in the tensile fracture gradually reduces with the increasing of extrusion temperature. In conclusion, the tin bronze QSn7-0.2 material obtains the best plastic at 720 ℃ during the extrusion forming.
出处
《锻压技术》
CAS
CSCD
北大核心
2018年第1期160-164,共5页
Forging & Stamping Technology
基金
山西省科技攻关资助项目(20120321035-04)
关键词
挤压温度
锡青铜
连杆衬套
微观组织
断口金相
extrusion temperature
tin bronze
connecting rod bushing
microstructure
fracture metallography
