CN108286032A

CN108286032A - A kind of chromaluminosiliconizing technology of high-efficiency and economic of steel

Info

Publication number: CN108286032A
Application number: CN201810039645.4A
Authority: CN
Inventors: 谢飞; 徐少强
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2018-01-16
Filing date: 2018-01-16
Publication date: 2018-07-17

Abstract

The present invention is a kind of technology for efficiently and economically penetrating into chromium aluminium silicon simultaneously in steel surface, to improve the high temperature oxidation resistance and wearability of steel.Between 750 DEG C to 900 DEG C, diffusion medium is made of the permeation treatment temperature of the technology high-carbon chromium iron, aluminium powder, iron powder, silicon carbide, ammonium chloride powders and charcoal powder etc.；Promote high carbon ferro-chrome, silicon carbide, aluminium powder etc. to be reacted with ammonium chloride using AC field, high concentration activity chromium atom, silicon atom, aluminium atom are obtained under less than conventional process temperature condition；The permeation speed of chromium, aluminium, silicon in relatively low treatment temperature is effectively improved with the heat effect and electromagnetic action of AC field；To stablize co-penetration technology and the infiltration capacity of silicon in infiltration layer is adjusted by adjusting iron powder addition.Compared with traditional chromaluminosiliconizing technique, the treatment temperature of the technology of the present invention is relatively low, and cost of material is less expensive, can significantly save the process material cost, and permeation speed highest can be improved 6 times, realize the chromaluminosiliconizing of high-efficiency and economic.

Description

A kind of chromaluminosiliconizing technology of high-efficiency and economic of steel

Technical field：

The technology that the invention belongs to be modified to metal parts surface is refered in particular to a kind of for improving steel material parts list Face is wear-resisting, the resistance to high temperature oxidation and corrosion resisting property energy-efficient method for preparing chromium aluminium silicon compisite seeping layer.

Background technology：

Powder method chromaluminosiliconizing technology is to use powder penetrating agent by three kinds of chromium, aluminium, silicon elements while penetrating into steel material The workpiece surface of making forms the ternary co-osmosized layer of chromium aluminium silicon, is mainly used for improving the high temperature oxidation resistance and corrosion resistance of workpiece.

Powder method chromaluminosiliconizing process, which is generally decomposed by penetration enhancer, generates active chromium, aluminium, silicon atom or containing chromium, aluminium, silicon Active group, active atomic/active group diffusion are being oozed workpiece surface absorption and reaction, are finally contained in workpiece surface formation Compound/solid solution of chromium, aluminium, silicon.Under conditions of high-temperature oxydation, chrome green, three can be formed by being oozed workpiece surface Al 2 O, silica combined oxidation layer, can effectively improve the high temperature oxidation resistance of workpiece；In corrosive medium, infiltration layer In chromium and silicon can increase substantially the corrosion resistance of workpiece.

In conventional powder method chromaluminosiliconizing, active silicon atom/reactive silicon-containing groups mainly by the ferrosilicon of higher price/ Silica flour provides, and materially increases process costs；In addition, in traditional chromaluminosiliconizing, active atomic/active group Generation, diffusion, absorption and reaction process all rely on heating temperature, so improve infiltration rate main means be improve heating temperature Degree and extension heating and thermal insulation time, so not only so that energy consumption increases, while excessively high heating temperature and prolonged heat are protected Temperature can also reduce the mechanical performance of most of processed workpiece matrix.And in the general electric field powder method chromium using traditional diffusion medium In Al-Si co-infiltrating, there is also ooze expand during electric pulse field parameter it is unstable, control difficulty is big, permeation layer thickness and the more difficult regulation and control of component The problem of.

Invention content：

It is an object of the invention to overcome the shortcoming of conventional powder method chromaluminosiliconizing technology, a kind of new height is provided Imitate economic chromaluminosiliconizing technology.This technology is realized by following technical proposal.

It is oozed workpiece by placing a pair of parallel electrode in oozing tank in sealing in the chromaluminosiliconizing stage and is placed in parallel electricity Between pole, diffusion medium, which fills up, oozes tank, by parallel pole to penetration enhancer and oozed workpiece apply AC field, penetration enhancer is by 1~25% High-carbon chromium iron, 0.5~8% aluminium powder, 1~20% iron powder, 45~95.5% carborundum powders, 1% ammonium chloride powders and 1% charcoal powder It constitutes, it is 750~900 DEG C, field current ranging from 0.5~8A to ooze expansion heating temperature range, and soaking time is 2~6 hours.It protects After temperature, oozes tank and cool to room temperature with the furnace, take out workpiece.

Main advantages of the present invention are on the one hand the iron powder in penetration enhancer can improve the electric conductivity of penetration enhancer, it is energy saving simultaneously Improve the stability of electric field action；On the other hand in penetration enhancer reaction, iron powder can be with a certain amount of active silicon atom/silicon-containing group In conjunction with to regulate and control silicone content in infiltration layer, to ensure quality layer.Meanwhile using electric field action, promoting silicon carbide and ammonium chloride Powder reacts, and under conditions of not adding ferrosilicon/silica flour, can generate enough active silicon atom/groups, reduce cost；Cheap chlorine Workpiece surface can be activated by changing ammonium；The heat effect of ac magnetic field, " collection skin " effect increase penetration enhancer of induction effect and alternating current Activity and the diffusion admittance for being oozed part surface layer accelerate diffusion, improve infiltration rate.

Specific implementation mode：

Embodiment 1：

Ooze material：45 steel；Chromaluminosiliconizing medium forms：For chromium agent (high carbon ferro-chrome, content 1%), for aluminium agent (aluminium powder, Content be 2%), process stabilizing agent (iron powder, content 2%), for silicea and filler (silicon carbide, content 93%)；Activation Agent (ammonium chloride powders, content 1%)；Antiseize lubricant (charcoal powder, content 1%).Control experiment diffusion agent formulation：1% high carbon chromium Iron powder, 2% aluminium powder, 95% carborundum powder, 1% ammonium chloride and 1% charcoal powder.

Sample is placed in and is oozed in tank between two parallel plate electrodes, two electrodes are connected in a voltage by conducting wire respectively In the 50Hz AC powers that 0~250V ranges are continuously adjusted, electrode and sample are sealed in together with chromaluminosiliconizing medium and ooze tank In, it is placed in stove from room temperature and rises to 800 DEG C, apply the alternating current of 2A respectively in two interpolars, keep the temperature 4 hours, be furnace-cooled to room temperature, Take out sample.

Not plus the contrast experiment of iron powder is during applying electric field, must be kept under 100~150V voltages after twenty minutes, electricity Field current can be only achieved 2A, and voltage slowly reduces thereafter, at the end of experiment, burning voltage 60V；And the experiment for adding iron powder exists It during applying electric field, keeps electric current being made to reach 2A in 15 minutes at 100~150V, voltage slowly reduces thereafter, experiment At the end of, burning voltage 45V.Using the diffusion medium containing 2% iron powder, gained infiltration layer surface layer Vickers hardness reaches HV430, than not The hardness of iron powder is added to improve 100HV；Meanwhile infiltration layer surface layer silicon atom content reduces, and improves infiltration layer toughness.

Embodiment 2：

Oozed material：45 steel；Chromaluminosiliconizing medium forms：For chromium agent (high carbon ferro-chrome, content 5%), for aluminium agent (aluminium Powder, content 0.5%), process stabilizing agent (iron powder, content 1%), for silicea and filler, (silicon carbide, content are 91.5%)；Activator (ammonium chloride powders, content 1%)；Antiseize lubricant (charcoal powder, content 1%).

Co-infiltrating method and device are the same as embodiment 1.800 DEG C of permeation temperature, soaking time 4 hours, electric field 0.5A.Comparison is real Test the conventional chromaluminosiliconizing to use identical penetration enhancer, being not powered on field.

The sample for applying electric field obtains~108 μm of chromaluminosiliconizing layer, and infiltration layer object mutually mainly has Fe₃Si, Al_0.3Fe₃Si_0.7And CrFe₈Si, and under same recipe, the specimen surface alloying layer thickness for not applying electric field action is only~76 μm, Si is free of in the object phase of infiltration layer surface layer.Two kinds of samples are placed in high-temperature oxydation 50 hours at 800 DEG C, the unit plane of electric field treatment sample Product weightening only has the 1/2 of conventional permeation sample, and high temperature oxidation resistance is increased dramatically.

Experimental example 3：

Oozed material：45 steel；Chromaluminosiliconizing medium forms：For chromium agent (high carbon ferro-chrome, content 5%), for aluminium agent (aluminium Powder, content 0.5%), process stabilizing agent (iron powder, content 10%), for silicea and filler, (silicon carbide, content are 82.5%)；Activator (ammonium chloride powders, content 1%)；Antiseize lubricant (charcoal powder, content 1%).The penetration enhancer of contrast experiment In without iron powder (with equivalent silicon carbide substitute).

Co-infiltrating method and device are the same as embodiment 1.Permeation temperature is respectively 750 DEG C and 900 DEG C, soaking time is 6 hours, electricity Field current is 2A.

After 750 DEG C of permeations, XRD analysis shows that through being free of iron powder penetration enhancer processing sample surface layer be mainly Fe₃Si phases, and The experimental sample surface layer for adding 10% iron powder is mainly Cr and Al_0.3Fe₃Si_0.7；After 900 DEG C of permeations, two kinds of penetration enhancer conditions Under, 3 times when sample alloying layer thickness is approximately 750 DEG C, reach~360 μm, but through the phase composition of the processing sample of penetration enhancer containing iron powder Middle Si contents reduce.

Claims

1. a kind of method that high-efficiency and economic chromaluminosiliconizing is carried out to steel workpiece, it is characterized in that：First workpiece and chromium aluminium silicon are total to Penetration enhancer is sealed in heat resisting steel with fire clay and oozes in tank, the heating and thermal insulation at 750~900 DEG C, by ooze be arranged in tank it is a pair of flat Row electrode applies AC field to diffusion medium and workpiece, and carrying out AC field to workpiece enhances powder method chromaluminosiliconizing, exchange Field current is 0.5~5A, and soaking time is 2~6h, obtains the co-penetration layer that thickness is 75~360 μm.

2. realize chromaluminosiliconizing medium described in claim 1, by for chromium agent, for aluminium agent, for silicea, process stabilizing agent, activation Agent (1%NH₄Cl), the compositions such as antiseize lubricant (1% charcoal powder) and filler.

3. realize claim 1 and 2 described in chromaluminosiliconizing medium in for chromium agent be high-carbon chromium iron, granularity be 60~ 400 mesh, content is 1~25% in diffusion medium.

4. realizing that in the chromaluminosiliconizing medium described in claim 1 and 2 be chemical pure or high purity aluminum powder for aluminium agent, granularity is 40~500 mesh, content is 0.5~8% in diffusion medium.

5. realizing that in the chromaluminosiliconizing medium described in claim 1 and 2 be silicon carbide for silicea, granularity is 30~500 mesh, Content is 45~95.5% in diffusion medium, and silicon carbide is filler simultaneously.

6. realizing the chromaluminosiliconizing medium described in claim 1 and 2, process stabilizing agent is added in diffusion medium, stabilizer is industry Straight iron powder or high-purity iron powder, granularity are 60~400 mesh, and content is 1~20% in diffusion medium.