CN1118016A - Wear-resisting and corrosion-resisting hard-alloy material - Google Patents

Abstract

The present invention relates to an anti-abrasive corrosion-resisting hard alloy material mainly used for manufacturing mechanically-sealing friction pairs under the condition of corrosion behaviour. The main ingredients of said invention are: 0.5-2.5% of matrix melal nickel, 0.1-0.5% of chromium, 0.5-1% of molybdenum, 0.1-0.5% of cobalt and the rest is tungsten carbide. As compared with YG6 alloy material said invention has the advantages of good physical-mechanical properties, high resistance to corrosion and low cost.

Description

A kind of wear-resisting, corrosion-resisting hard-alloy material

The invention belongs to the Hardmetal materials technical field.Be suitable as in the corrosive medium particularly mechanical seal fastness material under high temperature (boiling) etching condition.

At present, W-Co kind (the YG6 trade mark) alloy (composition is than tungsten 94%, and cobalt 6% is seen documents) is generally adopted in mechanical seal.This alloy rigidity high-wear resistance is good and be applied to mechanical seal the earliest.Its shortcoming is: this type of alloy corrosion resistance is poor, and W-Co kind alloy bonding metal is rare precious metal one cobalt, makes the W-Co kind cost of alloy greatly improve, so in use be subjected to certain limitation.

Along with developing rapidly of China's oil, chemical industry, the working condition of mechanical seal also becomes increasingly complex, for example; The requirement of, ultra-high voltage corrosion-resistant, high temperature resistant to material, ultra-high speed, radioprotective and the particle-resistant wearing and tearing in corrosive medium etc. makes general Wimet be difficult to adapt to fully.

The objective of the invention is to adopt the producing and manufacturing technique of existing alloy, by reducing the content of matrix metal in the alloy, metals such as selection resistant metal interpolation constituent element nickel replace the matrix metal cobalt, so that the content of rare precious metal cobalt descends significantly in the Wimet, thereby be implemented under the situation that does not reduce original physics-mechanical performance index, improve the corrosion resisting property of Wimet and the task of reduction material cost.

The present invention is realized by following technical scheme:

A kind of wear-resisting, corrosion-resisting hard-alloy material, its matrix metal proportioning components is: nickel 0.5～2.5%, chromium 0.1～0.5%, molybdenum 0.5～1%, cobalt 0.1～0.5%, all the other are wolfram varbide.

The present invention takes the powder metallurgical technology to produce: proportioning components: 0.5～2.5% nickel, and 0.1～0.5% chromium, 0.5～1.0% molybdenum, 0.1～0.5% cobalt, all the other are tungsten-carbide powder.With the powder stock mixing wet-milling of above-mentioned composition, ratio of grinding media to material is 3: 1; Wet grinding media: alcohol; The wet-milling time: 72～96 hours.After the wet-milling, adopt vacuum-drying, drying temperature: 80-120 ℃, before the moulding, add the rubber-moulding agent.Forming pressure: 1 ton/cm2.Blank after the moulding under 1450 ℃～1500 ℃ temperature, vacuum sintering 1～2 hour.Vacuum tightness: 10-1～10-2 torr.So far can produce wear-resisting, the corrosion resistant Hardmetal materials of the YCN3 trade mark.

Test with use practice to show that the YCN3 Hardmetal materials compares with the YG6 tungsten cobalt alloy and have following outstanding feature:

1. has good physics-mechanical property

The YCN3 alloy has good physics-mechanical property, its density, hardness, wear resistance are higher than the YG6 alloy, and have lower thermal expansivity and good heat-conducting, with same material to the mill, frictional coefficient is lower than the YG6 alloy, and its physics-mechanical property sees Table (one).

2. resistance to corrosion is strong

The alloy of the YCN3 trade mark has excellent chemical stability, resistance to corrosion is strong, in acidic medium (room temperature), its etching extent on average reduces an order of magnitude than the YG6 tungsten cobalt alloy, in alkaline medium, its etching extent is zero, especially under high temperature (boiling) etching condition, the resistance to corrosion of YCN3 alloy is bigger than the amplitude that improves with the YG6 alloy phase, sees Table (two).

3. save rare precious metal

The content of rare precious metal cobalt makes the alloy material cost reduce greatly in the alloy owing to having reduced.The contrast of novel YCN3 alloy material and former YG6 alloy material performance and every index is referring to table

One with table two:

Table one is new and old Hardmetal materials YCN3 and the contrast of YG6 physics one mechanical performance index.

Table two is the contrast of new and old alloy material YCN3 and YG6 corrosion resistance nature index.

Be applicable to because the YCN3 alloy has above-mentioned tangible advantage and be produced on particularly mechanical seal fastness material under high temperature (boiling) condition of corrosive medium.

The invention will be further described below in conjunction with embodiment.

The present invention adds an amount of matrix metal nickel, chromium, molybdenum, cobalt based on corrosion resistant metallic carbide one wolfram varbide.The addition of various compositions in the present embodiment (is example with 100g) is: nickel 2.3g, and chromium 0.5g, molybdenum 0.7g, cobalt 0.5g, all the other are wolfram varbide 96g.Above composition is metal-powder, and each powder stock is mixed wet-milling (wet-milling time: 8.5 hours) in alcohol, and mixed slurry is crossed 300 order copper wire screen clothes, through 80 ° of vacuum-dryings, adds the rubber-moulding agent before the moulding, and drying and screening is with 1 ton/cm ²Pressure forming, the blank ring after the moulding is at 1450 ℃+30 ℃, sintering is 2 hours in the vacuum sintering furnace, final dimension is φ 55 * φ 49 * 10 (mm).

The YCN3 alloy is through mechanical seal test examination, and its rub proofness and sealing property all reach the design requirements of mechanical seal.

Table (one) alloy physics-mechanical property

Test item	YCN3	YG6
			Density (g/cm3) hardness (HRA) bending strength (N/mm2) thermal coefficient of expansion (X10-6/ ℃) thermal conductivity factor (w/m ℃) coefficient of friction	15.0～5.3  91  1296  4.3  93  0.05	14.6～15.0    89.5    1421    4.7    92    0.06

Table (two) alloy corrosion resistance energy

The trade mark	98％HNO 3		30％HCl		50％H 2SO 4		50％H 3PO 4
									Normal temperature	Boiling	Normal temperature	Boiling	Normal temperature	Boiling	Normal temperature	Boiling
	YCN3 YG6	0.335 1.65	0.557 5.1	0.18 1.85	9.37 seriously corroded	0.105 0.1035	0.65 4.187	0.0071 0.01025									0.151 0.52

The trade mark	98% acetic acid		38％HNO 3＋62％H 2SO 4		40％NaOH＋20％NaCl
							Normal temperature	Boiling	Normal temperature	Boiling	Normal temperature	Boiling
	YCN3 YG6	0 0.0775	0.393 0.98	0.0345 0.058	0.737 2	0 0.022							0 0.143

Claims (1)

1. wear-resisting, corrosion-resisting hard-alloy material is characterized by the matrix metal composition proportion and is: nickel 0.5～2.5%, and chromium 0.1～0.5%, molybdenum 0.5～1.0%, cobalt 0.1～0.5%, all the other are wolfram varbide.