CN101992263A

CN101992263A - Process for large high-alloy steel resin bonded sand mould composite coating

Info

Publication number: CN101992263A
Application number: CN2010105351097A
Authority: CN
Inventors: 卜伟; 施风华; 龚圣峰
Original assignee: Shanghai Institute Of Machine Building Technology Co Ltd
Current assignee: Xin Technology (Shanghai) Material Technology Co., Ltd.
Priority date: 2010-11-08
Filing date: 2010-11-08
Publication date: 2011-03-30
Anticipated expiration: 2030-11-08
Also published as: CN101992263B

Abstract

The invention discloses a process for a large high-alloy steel resin bonded sand mould composite coating. The large high-alloy steel resin bonded sand mould composite coating comprises three layers of coatings, wherein the primer is an alcohol based coating, the second layer is a composite aggregate waterborne coating, and the outermost layer is a waterborne coating. When in use, the three layers of coatings are coated under the control of a certain Baume degree. In the composite coating, the primer has strong adhesion to a sand mould and ensures shielding performance of the coating; the second layer is the composite aggregate waterborne coating, which not only increases the sintering property of the coating, but also reduces the production cost; the top coating is a zircon powder waterborne coating, which ensures sufficient refractoriness in contract with molten steel, achieves better levelling property and higher surface fineness than an alcohol based coating, effectively improves the surface quality of a casting and achieves high comprehensive property than a single coating. By the process of the composite coating, excellent comprehensive property is achieved, the thickness of the coating is reduced by 20%, and the size accuracy of the casting is improved greatly.

Description

A kind of composite dope layer process that is used for large-scale high-alloy steel resin bonded sand mould

Technical field

The present invention relates to a kind of foundry facing technology, relate in particular to a kind of resin bonded sand mould foundry facing technology.

Background technology

For large-scale high-alloy steel resin bonded sand mould, cast paint needs enough aggregate refractoriness, smooth surface quality as the founding materials of a kind of effective shielding molten steel, sand mold.Coating often needs at least three times ability to obtain enough coating layer thicknesses.For heavy castings, use the drying of water based paint to need the long time, if all use water based paint, certainly will influence the progress of production.If but all use alcohol-base paint, really on isolated moisture and drying, curing rate, has clear superiority than water based paint, but the sand mold of heavy castings all uses the mode of igniting, has danger after all, and the surface quality of alcohol-base paint does not have water based paint exquisiteness, smooth, just causes its cast(ing) surface comparatively coarse yet.

Still there is not a kind of technology can control the characteristic separately of reasonably comprehensive alcohol radical, water based paint in the prior art by prescription and state, the operational characteristic of mating large-scale resin sand, high alloy steel part again, improve coating combination property, enhance productivity, improve surface quality of continuous castings.

Summary of the invention

Technical problem to be solved by this invention provides a kind of large-scale high-alloy steel resin bonded sand mould that is used for, combination properties such as adaptability, adhesiveness better composite dope layer process.

For solving the problems of the technologies described above, technical scheme provided by the invention is as follows:

A kind of composite dope layer process that is used for large-scale high-alloy steel resin bonded sand mould, coating at described sand mold surface of internal cavity divides three layers of brushing, and each composition weight percentage composition of the primer that contacts with sand mold is: zirconium English powder 70%, vinsol resin 0.3%, novolac resin 0.8%, lithium bentonite 1.5%, isopropyl alcohol 27.4%;

Comprise the composite refractory of forming by bauxite, zirconium English powder, pyrophillite in the second layer coating composition, and its weight portion mixing ratio is: 6: 13: 1, each composition weight percentage composition of second layer coating is: composite refractory 70%, industrial metasilicate 1.5%, sodium bentonite 1.5%, sodium dihydrogen phosphate 1%, all the other components are water;

Each composition weight percentage composition of outermost layer coating materials is: zirconium English powder 74%, vinegar uncle emulsion 2.2%, suspending agent 2.5%, association thickener 1.5%, and all the other components are water;

In the brushing paint process, primer control Baume degrees when brushing is 75～85 ° of B é, adjusts Baume degrees with the industrial alcohol of content more than 99% in casting mold cavity, and for big thick capping, Xiao Bao spare takes off limit;

Second layer coating control Baume degrees when brushing is 70～80 ° of B é, adjusts Baume degrees with the industrial alcohol of content more than 99%, and for big thick capping, Xiao Bao spare takes off limit;

Coating materials is 70～75 ° of B é of control Baume degrees when brushing, adjust Baume degrees with water, to guarantee enough coating layer thicknesses, good brushing performance, fine and smooth face coat.

Composite dope layer of the present invention is: with Zircon powder alcohol group dope as the primer that directly contacts with the waterglass sand mold, because alcohol-base paint is stronger to the adhesive force of sand mold, can guarantee the sufficiently high refractoriness of coating, compound binding agent can provide effectively shielding between sand mold and the water in air branch simultaneously, avoid guaranteeing the shielding properties of coating because problems such as the sand mold intensity reduction that water translocation causes, the deterioration of coating user mode, holiday produce; Second layer coating adopts bauxite, zirconium English powder, the compound aggregate water based paint of pyrophillite, though refractoriness has part to reduce, has increased the agglutinating property of dope layer, has reduced production cost simultaneously; Coating materials adopts zirconium English powder water based paint, both guaranteed refractoriness enough when contacting with molten steel, also can obtain effectively improving the surface quality of foundry goods, make this dope layer have the combination property that surpasses single coating than the better levelability of alcohol-base paint, surperficial fine and smooth degree.And obtain preparing three coatings and, could obtaining more excellent combination property according to this three coating of above-mentioned method brushing by above-mentioned three coating components through a large amount of tests; And draw through repetition test, if use alcohol-base paint separately for this large-scale high-alloy steel foundry goods, the thickness of its dope layer must be brushed to the effect that just can reach qualified dope layer between 1 to 1.2 centimetre, and use composite dope layer of the present invention, the thickness of its coating can be controlled between 0.8 to 0.9 centimetre, just can play shielding scab, improves the effect of surface quality, and owing to the thickness of coating reduces about 20%, so the dimensional accuracy of foundry goods obviously is improved.

Description of drawings

For above-mentioned purpose of the present invention, feature and advantage can be become apparent, below in conjunction with accompanying drawing the specific embodiment of the present invention is elaborated, wherein:

Fig. 1 is used for the preparation section schematic diagram of the composite dope coating of large-scale high-alloy steel resin bonded sand mould for the present invention.

The specific embodiment

The composite dope layer process that is used for large-scale high-alloy steel resin bonded sand mould of the present invention is at resin bonded sand mould surface of internal cavity brushing primer, second layer coating and coating materials three coating layers.At first according to the method preparation coating of Fig. 1, each composition weight percentage composition of primer is: zirconium English powder 70%, vinsol resin 0.3%, novolac resin 0.8%, lithium bentonite 1.5%, isopropyl alcohol 27.4%;

Each composition weight percentage composition of outermost layer coating materials is: zirconium English powder 74%, vinegar uncle emulsion 2.2%, suspending agent 2.5%, association thickener 1.5%, all the other components are water.

In casting mold cavity in the brushing paint process, primer control Baume degrees when brushing is 75～85 ° of B é, adjusts Baume degrees with the industrial alcohol of content 99% or more then, and for thick capping greatly, Xiao Bao spare takes off limit;

Following table be each embodiment in casting mold cavity in the brushing paint process, the parameter during three coating brushings is selected:

Select the composite dope and the painting way of uniqueness of the present invention for use, the thickness of die cavity dope layer be starkly lower than traditional coating coating mode 1 to 1.2 centimetre the effective thickness that must be brushed to, both improve surface quality of continuous castings, also obviously improved the dimensional accuracy of foundry goods.

Claims

1. composite dope layer process that is used for large-scale high-alloy steel resin bonded sand mould is characterized in that:

Coating at described sand mold surface of internal cavity divides three layers of brushing, and each composition weight percentage composition of the primer that contacts with sand mold is: zirconium English powder 70%, vinsol resin 0.3%, novolac resin 0.8%, lithium bentonite 1.5%, isopropyl alcohol 27.4%;