3-Dvelocity and temperature fields of mold filling and solidification processes of large-sized castingswere calculated,and the efficiency and accuracy of numerical calculation were studied.The mold filling andsolidifi...3-Dvelocity and temperature fields of mold filling and solidification processes of large-sized castingswere calculated,and the efficiency and accuracy of numerical calculation were studied.The mold filling andsolidification processes of large-sized stainless steel,iron and aluminum alloy castings were simulated by using ofnew scheme;their casting processes were optimized,and then applied to produce castings.展开更多
The objective of this paper is to review the factors influencing the formation of degenerated graphite layers on the surfaces of ductile iron castings for chemical resins-acid molding and core-making systems and how t...The objective of this paper is to review the factors influencing the formation of degenerated graphite layers on the surfaces of ductile iron castings for chemical resins-acid molding and core-making systems and how to reduce this defect. In the resin mold technique the sulphur in the P-toluol sulphonic acid （PTSA）, usually used as the hardener, has been identified as one factor causing graphite degeneration at the metalmold interface. Less than 0.15% S in the mold （or even less than 0.07% S） can reduce the surface layer depth. Oxygen may also have an effect, especially for sulphur containing systems with turbulent flows in the mold, water-bearing no-bake binder systems, Mg-Silica reactions, or dross formation conditions. Despite the lower level of nitrogen in the iron melt after magnesium treatment （less than 90 ppm）, nitrogen bearing resins have a profound effect on the frequency and severity of surface pinholes, but a limited influence on surface graphite degeneration.展开更多
通过分析实型铸造转移涂料的性能特点,设计转移涂料的成分,采用四因素三水平的正交试验,成功配制了性能优良的转移涂料。耐火粉料成分由75%高铝矾土、5%石英、8%滑石粉、5%土状石墨、7%的Fe_2O_3粉组成;粘结剂为2.5%的2123树脂和1%的正...通过分析实型铸造转移涂料的性能特点,设计转移涂料的成分,采用四因素三水平的正交试验,成功配制了性能优良的转移涂料。耐火粉料成分由75%高铝矾土、5%石英、8%滑石粉、5%土状石墨、7%的Fe_2O_3粉组成;粘结剂为2.5%的2123树脂和1%的正硅酸乙酯;悬浮剂为耐火粉料的0.6%PVB和1.5%凹凸棒土,以及600 m L/100 g的载液异丙醇。展开更多
文摘3-Dvelocity and temperature fields of mold filling and solidification processes of large-sized castingswere calculated,and the efficiency and accuracy of numerical calculation were studied.The mold filling andsolidification processes of large-sized stainless steel,iron and aluminum alloy castings were simulated by using ofnew scheme;their casting processes were optimized,and then applied to produce castings.
文摘The objective of this paper is to review the factors influencing the formation of degenerated graphite layers on the surfaces of ductile iron castings for chemical resins-acid molding and core-making systems and how to reduce this defect. In the resin mold technique the sulphur in the P-toluol sulphonic acid （PTSA）, usually used as the hardener, has been identified as one factor causing graphite degeneration at the metalmold interface. Less than 0.15% S in the mold （or even less than 0.07% S） can reduce the surface layer depth. Oxygen may also have an effect, especially for sulphur containing systems with turbulent flows in the mold, water-bearing no-bake binder systems, Mg-Silica reactions, or dross formation conditions. Despite the lower level of nitrogen in the iron melt after magnesium treatment （less than 90 ppm）, nitrogen bearing resins have a profound effect on the frequency and severity of surface pinholes, but a limited influence on surface graphite degeneration.
文摘通过分析实型铸造转移涂料的性能特点,设计转移涂料的成分,采用四因素三水平的正交试验,成功配制了性能优良的转移涂料。耐火粉料成分由75%高铝矾土、5%石英、8%滑石粉、5%土状石墨、7%的Fe_2O_3粉组成;粘结剂为2.5%的2123树脂和1%的正硅酸乙酯;悬浮剂为耐火粉料的0.6%PVB和1.5%凹凸棒土,以及600 m L/100 g的载液异丙醇。
