Production method for as-cast high-performance ductile iron QT600-10 by precision-investment casting

Abstract

The invention provides a production method for as-cast high-performance ductile iron QT600-10 by precision-investment casting, wherein a matrix of the as-cast high-performance ductile iron QT600-10 is a mixture of ferrite and pearlite; the pearlite accounts for 35%-55%, the nodulizing grade ranges from grade I to grade II, and the size of graphite ranges from grade VI to grade VII; the material comprises the following final chemical components in percentage by mass: 3.3-3.6% of C, 2.8-3.0% of Si, 0.2-0.4% of Mn, less than or equal to 0.035% of P, less than or equal to 0.02% of S, 0.4-0.6% of Cu, 0.035-0.055% of Mg, 0.02-0.04% of RE and the balance Fe; and a dam type nodulizing treatment and three-time inoculation way is adopted. The produced as-cast high-performance ductile iron QT600-10 has tensile strength Rm greater than or equal to 600 MPa, and elongation after fracture A greater than or equal to 10%. By combining a precision-investment casting production way with a cooling way after shell casting, high-strength high-toughness ductile iron is produced by a precision-investment casting process, so that lightweight design development and production for car parts is realized by virtue of a near net-shape forming process.

Description

technical field [0001] The invention belongs to the field of high-performance metal materials, and relates to the production of investment casting high-performance ductile iron castings, in particular to a production method of investment casting precision casting high-performance ductile iron QT600-10. Background technique [0002] In order to reduce vibration, improve the driving comfort of passenger cars, reduce the quality of the whole vehicle, and improve the performance of automotive casting parts, more and more passenger car OEMs are willing to use ductile iron material, combined with investment casting, which is a near-net shape The process redesigns some steel castings and aluminum castings for lightweight structure. [0003] However, the tensile strength, elongation and other comprehensive properties of ordinary as-cast ductile iron such as QT400-18, QT450-10, QT500-7, QT600-3, QT700-2, etc. cannot be compared with the commonly used auto parts cast steel ZGD310-570 ...

AI Technical Summary

Problems solved by technology

[0005] Published related patents "Application No. 201410230659.6 A Production Method of High-Strength Ductile Iron", "Application No. 201110159298.7 A Production Method of QT600-10 Ductile Iron Camshaft" and "Application No. 201310731458.X A Cast Ferrite-Based Cast Iron Nodular cast iron QT600-10 production method" and other methods cannot stably achieve the required performance of as-cast QT600-10 in investment casting

[0006] At present, there is no process for producing cast ductile iron QT600-10 by investment casting