V型机体铸件裂纹缺陷分析解决

Analysis and solution of crack defects in V-shaped block castings

V型高速柴油机机体结构复杂,强度较高,在浇铸过程中普遍存在裂纹缺陷。以V型12缸机体为例,从产品结构、凝固原理、铸造工艺等方面分析了机体串水孔裂纹缺陷成形原因。通过改进产品结构,均匀过渡铸件壁厚,加大串水孔圆角和翻边可有效分散热应力;同时优化工艺参数和热处理工艺,将埋箱时间由18h延长至36h,充分释放铸件残余应力,最终彻底解决了机体铸件裂纹缺陷。

The V-type high-speed diesel engine has a complex structure and high strength,and cracks are common in the casting process.Taking the V-shaped 12-cylinder block as an example,the reasons for the formation of the water hole crack defects in the block have been analyzed from the aspects of product structure,solidification principle,and casting process.By improving the product structure,uniformly transitioning the wall thickness of the casting,increasing the fillet and flanging of the water string can effectively disperse the thermal stress;at the same time,the process parameters and heat treatment process have been optimized,and the embedding time has been extended from 18h to 36h,which fully releases the residual stress of the casting.Finally,the crack defect of the block casting has been completely solved.