CN1153831A

CN1153831A - Binary solid Ti-Al powder cocementing process on steel surface

Info

Publication number: CN1153831A
Application number: CN 96101715
Authority: CN
Inventors: 赵广亮; 钱士利; 黄月义
Original assignee: 赵广亮
Priority date: 1996-01-05
Filing date: 1996-01-05
Publication date: 1997-07-09

Abstract

The cocementing process uses binary Ti-Al cocementing agent compounded with aluminium trifluoride, titanium dioxide, ammonium chloride and cocementing material, which consists of active aluminium silicate molecular-sieve microball in 45-70% and ternary Al-Ti-Fe alloy powder 30-55%. The said process uses cocementing tank with separating board at its upper part and the separating board has mixture material of magnesium oxide and magnesium on it for absorbing corrosive gas and has gas guiding port and buffer bin for exhausting produced gas.

Description

The solid powder titanium-aluminum binary co-infiltration method on steel surface

The invention belongs to the metallic surface chemical heat treatment method.

The surface of steel is after titanium-aluminum binary oozes thermal treatment altogether, the surface of steel forms titanium-aluminium alloy diffusion layer, have good heat-resisting, wear resistance, at citric acid, tartrate, reach high temperature sulphur in the organic solutions such as naphthenic acid, has good solidity to corrosion in nitric acid, the salts solution, obviously be better than carbon steel, calorized steel, ooze titanium steel and 1cr18Ni9Ti stainless steel, especially in 30% sodium hydroxide solution, its solidity to corrosion surpasses nearly 9 times of 1Cr18Ni9Ti, so titanium-aluminum binary oozes steel altogether and has widely in industries such as oil, chemical industry, electric power, shipbuildings and use.

At present, domestic solid powder titanium-aluminum binary confusion technology to the steel surface does not have report as yet, external employing aluminium and titanium dioxide and halogenide proportioning component are carried out titanium-aluminum binary and are oozed altogether, there are following problem in its diffusion medium and processing method: 1) in the process heat treating processes, penetration enhancer is easy to harden, height when causing workpiece surface infiltration layer titanium-aluminium content, the time low inhomogeneous, the continuity of quality layer is difficult to control, quality product also just can't guarantee.2) technology adopts the penetration enhancer proportioning simple, unreasonable, causes penetration enhancer not reuse, and waste is big, and penetration enhancer is easy to oxidation, and is strict to Equipment for Heating Processing that technology adopts, the cost height.3) have etchant gas to discharge in the operational process of craft, coup injury heating installation and harm people's is healthy.

Purpose of the present invention promptly is in order to overcome the shortcoming of above-mentioned titanium-aluminum binary co-infiltration method, it is reasonable to propose a kind of diffusion agent formulation, can effectively guarantee quality product, penetration enhancer again can be reusable steel surface titanium-aluminum binary co-infiltration method, and make it have easy to operate, safety, can avoid the characteristics of equipment and human body infringement.

Main points of the present invention are that the prescription of titanium-aluminum binary diffusion medium that this method adopts is (weight percent): 4～10% aluminum trifluorides+5～10% titanium dioxide+0.1～2% ammonium chloride+material (surplus), wherein the proportioning of material (weight percent) is: 45～70% active silicic acid aluminum molecular screen microballoon+55～30% aluminium-titaniums-iron ternary alloy powder, wherein the aluminum trifluoride fineness can be φ 0.152～0.066, titanium dioxide φ 0.152～0.066, active silicic acid aluminum molecular screen microballoon φ 0.02～0.2, aluminium-titanium-iron ternary alloy powder φ 0.152～0.066.

The present invention is owing to the proportioning component that has adopted the penetration enhancer proportioning, particularly material that have the material composition is the mixture of aluminium-titanium-iron ternary alloy powder and active silicic acid aluminum molecular screen microballoon.Add aluminium-titanium-iron ternary alloy powder in the material, make penetration enhancer in technology heat-processed, effectively avoided aluminium in the penetration enhancer---the loss of titanium effective element, reaching penetration enhancer can reuse, simultaneously, solve the caking phenomenon of penetration enhancer in the process heat treating processes, guaranteed the continuity of infiltration layer; Add active silicic acid aluminum molecular screen microballoon in the material, the whole proportion of penetration enhancer is reduced greatly, each component of penetration enhancer is more prone to mix, and has further guaranteed quality layer.

Add aluminum trifluoride in the penetration enhancer, the active aluminum atom not only is provided, but also be good energizer and clean dirty agent; Add titanium dioxide, make that the balance of titanium content is guaranteed in the penetration enhancer.Add ammonium chloride in the penetration enhancer and play the energizer effect.

Operational process of craft of the present invention: at first institute's processing test specimen is put into titanium-aluminum binary and ooze case altogether, the penetration enhancer of packing into, capping, the case that oozes that will install is then placed in the process furnace, Heating temperature is 900～1100 ℃, time decides on required alloying layer thickness, is generally 4～12 hours, is cooled off then.

Accompanying drawing 1 provides titanium---and aluminum binary oozes the structural representation of case altogether.

The structure that titanium---aluminum binary oozes case altogether mainly includes case lid 1, dividing plate 3, casing 4, case lid 1 has up and down two-layer cover plate, consists of surge bunker 6, case lid between the two-layer cover plate Upper cover plate has set gas port 5, has set

gas port

7,8 on the lower cover, establishes in the casing Put dividing plate 3, set gas port 9 on the dividing plate 3, place magnesium and magnesian at dividing plate 3 Mix sealing filler material 2, so that penetration enhancer produces in technology heating process is harmful Gas HF, HCL and magnesium generation displacement reaction produce magnesium salts and hydrogen, have avoided heating The corrosion and damage of stove inner member reaches the impact to health, simultaneously the external oxygen of casing is advanced The row oxidation reaction is produced magnesia, effectively stops the scaling loss of penetration enhancer, fills in the gas port The high-temperature fibre cotton is arranged, be used for stoping penetration enhancer and mixing of sealing inserts to reach sealing and do With.

Embodiment 1:

Test specimen is: the weldless steel tube of φ 25 * 2.5 * 380, and material 20# steel, the diffusion agent formulation weight percent is:

Aluminum trifluoride 8%

Titanium dioxide 5%

Ammonium chloride 0.5%

Titanium-aluminium-iron ternary alloy powder 39.5% active silicic acid aluminum molecular screen, 950 ℃ of time of 50% Heating temperature, 4 hours alloying layer thickness 0.1mm layer surface microhardness 4016MPa layer surface aluminium content 16% (weight percent) layer surface titanium content 14% (weight percent) oozes the part surface aesthetic, be silver gray, infiltration layer is continuous, densification.Embodiment 2 test specimens are: 50 * 25 * 3 test piece, material are A ₃Steel diffusion agent formulation weight percent: aluminum trifluoride 10% titanium dioxide 10% ammonium chloride 1% titanium-aluminium-iron ternary alloy powder 45% active silicic acid aluminum molecular screen 1050 ℃ of time of 35% Heating temperature, 5 hours alloying layer thickness 0.2mm layer surface microhardness 4016MPa layer surface aluminium content 20% layer surface titanium content 18% oozes the part surface aesthetic, be silver gray, infiltration layer is continuous, densification.

Claims

1, the solid powder titanium-aluminum binary co-infiltration method on a kind of steel surface, place titanium-aluminum binary to ooze the diffusion medium of case altogether workpiece, heating is carried out titanium-aluminium and is oozed processing altogether, Heating temperature is 900～1100 ℃, time is 4-12 hour, cooling then is characterized in that: the consisting of of titanium-aluminum binary diffusion medium: aluminum trifluoride, titanium dioxide, ammonium chloride and material, and its proportioning (weight percent) is: 4～10% aluminum trifluorides+5～10% titanium dioxide+0.1～2% ammonium chloride+material (surplus); The composition of material and proportioning (weight percent) are: 45% active silicic acid aluminum molecular screen microballoon+55～30% aluminium-titanium-iron ternary alloy powder.

2, pressed powder titanium-aluminum binary the co-infiltration method on steel according to claim 1 surface, it is characterized in that: the structure that titanium-aluminum binary oozes case altogether mainly includes case lid (1), dividing plate (3), casing (4), case lid (1) has two-layer cover plate up and down, constitute surge bunker (6) between the two-layer cover plate, the case lid upper cover plate has set gas port (5), set gas port (7) (8) on the lower cover, dividing plate (3) is set in the casing, set gas port (9) on the dividing plate (3), go up placement magnesium and the magnesian sealing filler material (2) that mixes at dividing plate (3), in order to absorb etchant gas.