CN104741529A - Investment casting method of automobile heat-resisting steel exhaust manifold - Google Patents

Abstract

The invention belongs to metal casting technologies, and particularly relates to an investment casting method of an automobile engine heat-resisting steel exhaust manifold. The method comprises a wax mold manufacturing step, a mold shell manufacturing step, an alloy smelting step, a pouring step, a sand shakeout step and a cleaning step. According to the method, common defects of local shrinkage porosity, local shrinkage cavity and the like of an automobile engine heat-resisting steel exhaust manifold casting can be removed or reduced, and the higher technological yield is achieved.

Description

Heat-resistant steel exhaust manifold for automobile investment casting method

 

Technical field

The invention belongs to casting technology field, be specifically related to a kind of heat-resistant steel exhaust manifold for automobile investment casting method.

 

Background technology

Heat-resistant steel exhaust manifold for automobile investment casting method also also exists some problems at present, and cast-internal is organized thick, often has the casting flaw such as shrinkage porosite, pore, and casting quality is stable not, and percent defective is high, contaminated environment, and energy consumption is high.

 

Summary of the invention

In order to overcome the above-mentioned technical problem that prior art field exists, the object of the invention is to, a kind of heat-resistant steel exhaust manifold for automobile model casting manufacturing technique method is provided, eliminate or reduce the defects such as the common local Shinkage and dispersed porosity of automobile engine heat-resistant steel exhaust manifold foundry goods, and there is higher product yield.

Heat-resistant steel exhaust manifold for automobile model casting production technology provided by the invention, comprises the following steps:

(1) wax-pattern is manufactured: take urea as core material, water is dissolve medium; At fusion temperature 100-150 DEG C; Free casting forming method is adopted to make core under mold temperature 5080 DEG C of conditions: to adopt K-501 wax, at change wax temperature 80-100 DEG C; Penetrate wax temperature 50-70 DEG C; Penetrate wax pressure 20Kg/cm ²-60Kg/cm ²; Dwell time: 20S-80S; Wax-pattern is made under coolant water temperature: 5-25 DEG C condition; Use laminar flatiron, the connecting portion of wax-pattern is melted, make that wax-pattern is welded together is assembled into module;

(2) shell is manufactured: the oil removing of module and degreasing; Module is coated with coating and stucco: before being coated with coating, first coating is stirred; After coating coats, carry out stucco; Wherein layer of sand is three layers, is surface layer respectively: 320 order zirconium powders joined by Ludox, dry 5-10 hour; Transition zone: 320 order mullite powders joined by Ludox, dry 5-10 hour; Back-up coat: 320 order mullite powders joined by Ludox, dry 10-15 hour; Obtain shell blank;

(3) molten mistake fusible pattern: after coating and stucco layer bone dry also harden, melt dewax module with hot-water process, obtain shell;

(4) roasting shell: the shell after dewaxing is put into heating furnace, heats to 1000-1200 DEG C, insulation 0.5-2 hour; High-performance shell is obtained by said procedure;

(5) alloy melting: adopt intermediate frequency furnace melting, before cast, spectrum on line analyzes alloying component, guarantees to obtain the qualified cast product of composition;

(6) pour into a mould: pouring temperature 1580 DEG C, formwork preheat temperature 1000 DEG C, the duration of pouring 10S;

(7) knockout: adopt the mode that mechanical oscillation sand removal and chemical soda boiling sand removal combine;

(8) clear up.

Heat-resistant steel exhaust manifold for automobile model casting production technology provided by the invention, its beneficial effect is, eliminates or reduces the defects such as the common local Shinkage and dispersed porosity of automobile engine heat-resistant steel exhaust manifold foundry goods, and having higher product yield.

 

Detailed description of the invention

Below in conjunction with an embodiment, heat-resistant steel exhaust manifold for automobile model casting production technology provided by the invention is described in detail.

Embodiment

(1) wax-pattern is manufactured: take urea as core material, water is dissolve medium; Fusion temperature 125 DEG C; Free casting forming method is adopted to make core under mold temperature 5080 DEG C of conditions: to adopt K-501 wax, change wax temperature 86 DEG C; Penetrate wax temperature 63 DEG C; Penetrate wax pressure 45Kg/cm ²; Dwell time: 67S; Coolant water temperature: make wax-pattern under 13 DEG C of conditions; Use laminar flatiron, the connecting portion of wax-pattern is melted, make that wax-pattern is welded together is assembled into module;

(2) shell is manufactured: the oil removing of module and degreasing; Module is coated with coating and stucco: before being coated with coating, first coating is stirred; After coating coats, carry out stucco; Wherein layer of sand is three layers, is surface layer respectively: 320 order zirconium powders joined by Ludox, dry 7 hours; Transition zone: 320 order mullite powders joined by Ludox, dry 6 hours; Back-up coat: 320 order mullite powders joined by Ludox, dry 11 hours; Obtain shell blank;

(3) molten mistake fusible pattern: after coating and stucco layer bone dry also harden, melt dewax module with hot-water process, obtain shell;

(4) roasting shell: the shell after dewaxing is put into heating furnace, heats to 1130 DEG C, be incubated 1 hour; High-performance shell is obtained by said procedure;

(5) alloy melting: adopt intermediate frequency furnace melting, before cast, spectrum on line analyzes alloying component, guarantees to obtain the qualified cast product of composition;

(6) pour into a mould: pouring temperature 1580 DEG C, formwork preheat temperature 1000 DEG C, the duration of pouring 10S;

(7) knockout: adopt the mode that mechanical oscillation sand removal and chemical soda boiling sand removal combine;

(8) clear up.

Heat-resistant steel exhaust manifold for automobile model casting production technology, can eliminate or reduce the defects such as the common local Shinkage and dispersed porosity of automobile engine heat-resistant steel exhaust manifold foundry goods, and there is higher product yield.

Claims (1)

1. a molding sand method for casting production for heat-resistant steel exhaust manifold for automobile investment-casting, is characterized in that: said method comprising the steps of:

(1) wax-pattern is manufactured: take urea as core material, water is dissolve medium; At fusion temperature 100-150 DEG C; Free casting forming method is adopted to make core under mold temperature 5080 DEG C of conditions: to adopt K-501 wax, at change wax temperature 80-100 DEG C; Penetrate wax temperature 50-70 DEG C; Penetrate wax pressure 20Kg/cm ²-60Kg/cm ²; Dwell time: 20S-80S; Wax-pattern is made under coolant water temperature: 5-25 DEG C condition; Use laminar flatiron, the connecting portion of wax-pattern is melted, make that wax-pattern is welded together is assembled into module;

(2) shell is manufactured: the oil removing of module and degreasing; Module is coated with coating and stucco: before being coated with coating, first coating is stirred; After coating coats, carry out stucco; Wherein layer of sand is three layers, is surface layer respectively: 320 order zirconium powders joined by Ludox, dry 5-10 hour; Transition zone: 320 order mullite powders joined by Ludox, dry 5-10 hour; Back-up coat: 320 order mullite powders joined by Ludox, dry 10-15 hour; Obtain shell blank;

(3) molten mistake fusible pattern: after coating and stucco layer bone dry also harden, melt dewax module with hot-water process, obtain shell;

(4) roasting shell: the shell after dewaxing is put into heating furnace, heats to 1000-1200 DEG C, insulation 0.5-2 hour; High-performance shell is obtained by said procedure;

(5) alloy melting: adopt intermediate frequency furnace melting, before cast, spectrum on line analyzes alloying component, guarantees to obtain the qualified cast product of composition;

(6) pour into a mould: pouring temperature 1580 DEG C, formwork preheat temperature 1000 DEG C, the duration of pouring 10S;

(7) knockout: adopt the mode that mechanical oscillation sand removal and chemical soda boiling sand removal combine;

(8) clear up.