CN103357863A - A high wear-resistant powder metallurgy valve seat and its preparation method - Google Patents

Abstract

A high wear-resistant powder metallurgy valve seat and its preparation method, characterized in that it is made of the following raw materials in parts by weight: iron powder 99-102, graphite 1.2-1.4, chromium powder 1.4-1.6, molybdenum powder 0.2-0.3, Si1 .5-1.7, As0.5-0.9, Sb0.08-0.12, Sc0.04-0.07, ZrO ₂ 0.4-0.5, SiO ₂ 1.2-1.5, zirconium diboride 0.4-0.6, titanium diboride 0.3-0.5 , Dispersant 2-3. The invention can increase the wear resistance, high temperature resistance, corrosion resistance and radial crushing strength of the product.

Description

A high wear-resistant powder metallurgy valve seat and its preparation method

technical field

The invention relates to the field of powder metallurgy, in particular to a high wear-resistant powder metallurgy valve seat and a preparation method thereof.

Background technique

Powder metallurgy technology is a new type of technology that perfectly combines material science and metal forming technology. It is widely used in various industries because of its high efficiency, non-cutting processing, material saving, energy saving, and environmental protection.

The material composition of powder metallurgy structural parts is not limited by smelting. It can be added with alloy composition or other structural components, and can be adjusted according to the requirements in a considerable range, so that the mechanical properties can match the steel parts. Effect.

Powder metallurgy has a high degree of mechanization, which can not only reduce personnel, but also improve efficiency, thereby saving costs. Powder metallurgy technology can replace the traditional manufacturing process and save costs for the majority of traditional enterprises.

Therefore, it is of great significance to study the formula of powder metallurgy for various mechanical parts and adapt to different needs.

Contents of the invention

The purpose of the present invention is to provide a high wear-resistant powder metallurgy valve seat and its preparation method.

Technical scheme of the present invention is as follows:

A high wear-resistant powder metallurgy valve seat is characterized in that it is made of the following raw materials in parts by weight:

Iron powder 99-102, graphite 1.2-1.4, chromium powder 1.4-1.6, molybdenum powder 0.2-0.3, Si1.5-1.7, As0.5-0.9, Sb0.08-0.12, Sc0.04-0.07, ZrO ₂ 0.4 -0.5, SiO ₂ 1.2-1.5, zirconium diboride 0.4-0.6, titanium diboride 0.3-0.5, dispersant 2-3.

The dispersant is made of the following raw materials in parts by weight: aminopropyltriethoxysilane 1.5-1.8, zirconium boride 0.3-0.5, high wear-resistant carbon black 0.2-0.4, zirconium fluoride 0.2-0.5, di Methyl silicone oil 2.3-2.5, microcrystalline paraffin 3-4, carboxymethyl cellulose 2-3;

The preparation method is as follows: mixing all materials, grinding and dispersing evenly.

The preparation method of the high wear-resistant powder metallurgy valve seat is characterized in that it comprises the following steps:

(1) Mix the materials, stir evenly at 53-57°C for 40-50 minutes, put them into the mold, and press them into billets;

(2) Put the compact in a sintering furnace in a nitrogen atmosphere with an oxygen content of 0.1-0.2%, and sinter at a rate of 6-8°C/min to 450-480°C for 2-3 hours; Sintering at a rate of -12°C/min to 880-920°C for 2-3 hours; heating at a rate of 16-18°C/min to 1100-1190°C for 1-2 hours;

(3) Send the compact into the steam treatment furnace, and pass steam for 50-60 minutes under the condition of the temperature in the furnace at 450-490°C;

(4) Put the compact into the furnace at 320-340°C, keep it warm for 2-3 hours, and take it out.

the

The scientific formula of the invention adopts the combination of graphite and chromium, and the produced product has compact structure, good microstructure, few pores, and excellent structural rigidity, hardness, fatigue resistance and tensile strength. Moreover, due to the adoption of mold pressing, the equipment is simplified and the production cost is reduced.

The invention can increase the wear resistance, high temperature resistance, corrosion resistance and radial crushing strength of the product.

Detailed ways

A high wear-resistant powder metallurgy valve seat is made of the following raw materials (kg) in parts by weight:

Iron powder 102, graphite 1.4, chromium powder 1.4, molybdenum powder 0.2, Si1.7, As0.9, Sb0.12, Sc0.07, ZrO ₂ 0.5, SiO ₂ 1.2, zirconium diboride 0.6, titanium diboride 0.5 , Dispersant 3.

The dispersant is made of the following raw materials in parts by weight: aminopropyltriethoxysilane 1.8, zirconium boride 0.3, high wear-resistant carbon black 0.4, zirconium fluoride 0.5, dimethyl silicone oil 2.5, microcrystalline paraffin 3. Carboxymethyl cellulose 2;

The preparation method is as follows: mixing all materials, grinding and dispersing evenly.

A method for preparing a high wear-resistant powder metallurgy valve seat, comprising the following steps:

(1) Mix the materials, stir evenly at 53-57°C for 40-50 minutes, put them into the mold, and press them into billets;

(2) Put the compact in a sintering furnace in a nitrogen atmosphere with an oxygen content of 0.1-0.2%, and sinter at a rate of 6-8°C/min to 450-480°C for 2-3 hours; Sintering at a rate of -12°C/min to 880-920°C for 2-3 hours; heating at a rate of 16-18°C/min to 1100-1190°C for 1-2 hours;

(3) Send the compact into the steam treatment furnace, and pass steam for 50-60 minutes under the condition of the temperature in the furnace at 450-490°C;

(4) Put the compact into the furnace at 320-340°C, keep it warm for 2-3 hours, and take it out.

After testing, the heat treatment hardness of the present invention: HRC65; tensile strength: 1180MPa.

Claims (2)

1. high-wear-resistant powder metallurgy valve seating is characterized in that being made by the raw material of following weight portion:

Iron powder 99-102, graphite 1.2-1.4, chromium powder 1.4-1.6, molybdenum powder 0.2-0.3, Si1.5-1.7, As0.5-0.9, Sb0.08-0.12, Sc0.04-0.07, ZrO ₂0.4-0.5, SiO ₂1.2-1.5, zirconium diboride 0.4-0.6, titanium diboride 0.3-0.5, dispersant 2-3;

Described dispersant is made by the raw material of following weight portion: aminopropyl triethoxysilane 1.5-1.8, zirconium boride 0.3-0.5, high wear-resistant carbon black 0.2-0.4, zirconium fluoride 0.2-0.5, dimethicone 2.3-2.5, microcrystalline wax 3-4, carboxymethyl cellulose 2-3; The preparation method is: with each mixing of materials, grinding distribution evenly gets final product.

2. the preparation method of high-wear-resistant powder metallurgy valve seating according to claim 1 is characterized in that may further comprise the steps:

(1) with each mixing of materials, after stirring 40-50 minute under 53-57 ℃, the mould of packing into is pressed into base;

(2) pressed compact is placed in the sintering furnace, oxygen content is in the blanket of nitrogen of 0.1-0.2%, is warming up under the 450-480 ℃ of condition sintering 2-3 hour with 6-8 ℃ of/minute clock rate; Be warming up under the 880-920 ℃ of condition sintering 2-3 hour with 10-12 ℃ of/minute clock rate again; Be warming up under the 1100-1190 ℃ of condition sintering 1-2 hour with 16-18 ℃ of/minute clock rate;

(3) pressed compact is sent in the steam treatment stove, in stove, passed into steam 50-60 minute under temperature 450-490 ℃ the condition;

(4) pressed compact is put under the stove 320-340 ℃ condition again, be incubated 2-3 hour, take out and get final product.