WO2009143697A1

WO2009143697A1 - Steel shot grain and manufacturing method thereof

Info

Publication number: WO2009143697A1
Application number: PCT/CN2009/000572
Authority: WO
Inventors: 王奇; 冯艳华; 王静; 邱锋
Original assignee: 大丰市大奇金属磨料有限公司
Priority date: 2008-05-30
Filing date: 2009-05-25
Publication date: 2009-12-03
Also published as: CN100486773C; CN101337338A

Abstract

Steel shot grain for surface treatment is made of 0.75-0.80 weight percentage of carbon, 0.48-0.58 weight percentage of manganese, 0.22-0.26 weight percentage of silicon, 0.001-0.006 weight percentage of sulfur, 0.011-0.015 weight percentage of phosphorus, iron and other avoidable impurities. The hardness of the shot is measured under load with an average value of 640HV±30HV, and the deviation range of the hardness is ±25HV. The shot is manufactured by selecting suitable raw material, drawing the raw material into a steel wire, cutting the wire into small cylindrical cut sections, sieving the cut sections, detecting the cut sections and putting them in storage. A rounding and strengthening process can be alternatively added before sieving step.

Description

Steel shot and its manufacturing method

The present invention relates to a metal product, and more particularly to a reinforced steel shot which is a shot blast which is mainly used for metal surface treatment.

technical background

China's current production and use of steel shot, cast steel shot or reinforced steel shot blasting products, there are two main production processes, one is extracted from scrap steel and iron mud, and the other is produced by atomization. The main defects of the shot blasting produced by these two methods are that the element ratio is not easily controlled, and the hardness deviation is large. At the same time, the density and surface shape deviation of the shot blasting are also large, and such shot blasting is also prone to hollow and surface microcracking. Therefore, such shot blasting products have insufficient impact resistance and abrasion resistance during shot blasting or shot peening, are easily broken, and have a short service life. Especially when used for shot blasting and strengthening treatment of high-strength steel, such as for metal surface treatment in large aircraft manufacturing, aerospace, automobile, motorcycle, shipbuilding, transmission, spring manufacturing, etc., the disadvantages are particularly prominent. The strengthening effect of changing the surface stress state of the workpiece, hardening the surface of the workpiece, improving the wear resistance of the part and the fatigue resistance can not achieve the desired effect.

Summary of the invention

SUMMARY OF THE INVENTION The object of the present invention is to overcome the above drawbacks and to provide a reinforced steel shot which is high in surface strength, good in durability, and small in hardness deviation, and is suitable for surface treatment of high-end workpieces.

The technical solution of the present invention is:

The reinforced steel shots have a composition of carbon 0.75~0.80%, manganese 0.48~0.58%, silicon 0.22~0.26%, 0.001-0.006%, phosphorus 0.011~0.015%, and the balance is iron and unavoidable impurities.

The average hardness measured under the reinforced steel pellet load was 640 HV ± 30 HV.

The reinforced steel shot has a hardness deviation range of ±25 HV.

The preparation method of the reinforced steel shot is:

Selecting a material, drawing, cutting, screening, and testing,

Or: Select a material, a wire, a cut, a surface, a round, a sieve, a test, and a storage.

The material selection refers to the selection of the elemental composition ratio consistent with the finished reinforced steel shot, and the carbon spring steel wire with the hardness deviation within the standard hardness of the finished reinforced steel shot ± 50 HV is the raw material for production. The drawn wire refers to a cylindrical steel wire of different specifications between 0 and 2 mm, which is drawn by a product of 3 to 5 times. The cutting refers to cutting a cylindrical steel wire into small cylindrical segments of uniform length, the cutting length being consistent with the diameter of the cylindrical steel wire. The surface rounding strengthening refers to impact rounding and impact strong on the cylindrical section by using the rounding strengthening equipment. Chemical. The sieving refers to sieving 2 to 3 times according to the size specifications. The test refers to hardness and durability testing.

The reinforced steel shot provided by the invention is produced by using the profile carbon spring steel wire with the element composition ratio and the finished reinforced steel shot as the raw material, so the density of the strengthened steel shot and the element ratio are high, and the hardness deviation is relatively small; The reinforced steel shots produced by the production process do not exhibit hollow and surface cracking, have small surface shape differences, high surface strength and good durability. The reinforced steel shot provided by the invention is particularly suitable for surface treatment of high-end workpieces.

detailed description

A reinforced steel shot having a weight percentage composition of carbon 0.75~0.80%, manganese 0.48~0.58%, silicon 0.22~0.26%, sulfur 0.001~0.006%, phosphorus 0.011~.015%, balance iron and inevitable Impurities. The average hardness is 640 HV and the hardness deviation ranges from ±25 HV.

Reinforced steel shots can be divided into four categories according to their shape:

Cylindrical type - ^ code is Z;

Elliptical - codenamed G1;

Quasi-spherical type - codenamed G2;

Ball type - codenamed G3.

The production process of the above reinforced steel shot is:

Material selection, drawing, cutting, screening, inspection, storage,

The material selection refers to the ratio of the composition of the elements to the weight percentage of carbon 0.75~0.80%, manganese 0.48~0.58%, silicon 0.22~0.26%, sulfur 0.001~0.006%, phosphorus 0.011~0.015%, the amount of iron is iron and not Carbon spring steel wire for avoiding impurities is a raw material for production, and its hardness ranges from 640 ± 50 HV.

Drawing is the drawing of the raw material 3 to 5 times according to the product specifications, and the carbon spring wire is drawn into a cylindrical steel wire of different specifications between 0 and 2-3 mm;

Cutting refers to cutting a cylindrical steel wire into a small cylindrical section with the same length by a wire cutter. The cutting length is the same as the diameter of the cylindrical steel wire. The shearing section requires flat, no burrs, and no tailing.

Surface strengthening refers to the use of strengthening equipment to impact the cylindrical section. The reinforced equipment causes the cylindrical section to be shot at a speed of 60-100 m / sec. After a distance of 30 to 80 m, the inner wall of the reinforced chamber is impacted, and the shape and hardness are strengthened according to the different times of repeated impact strengthening.

Strengthen the specific time as follows:

Z : 0 minutes

G1 : 30~60 minutes G2: 60~90 minutes

G3: 80~120 minutes

Strengthen the hardness grade and hardness range of steel shots -

The method and steps of screening are:

1毫米。 Dimensional specification in the particle deviation +0. 1 mm, that is, the diameter of the mesh hole is the standard size specification +0. 1 mm;

2, the second screen: the size specification is a standard product, the particle deviation is approximately +0. 00 mm, that is, the screen hole diameter is the standard size specification;

3毫米。 The third dimension: the size of the particle deviation is -0. 1 mm, that is, the diameter of the mesh hole is the standard size specification -0. 1 mm;

4, Remove the surface of the irregular shape of the product, the pellet is magnified 25 times visual inspection, the disagreement rate is 0.3%.

Attached: The final sieving rate: Ζ ≤ 0. 7%, G1 ≤ 0. 5%, G2 ≤ 0. 5%, G3 0. 5%. Standard size specifications for pellets: 0. 20 ~ 2. 00 mm.

Test methods for screening and screening rates on the first, second and third screens:

Screening rate of the X-mesh - the percentage of residue remaining on the screen after screening through the screen as a percentage of the total. Screening rate of the X-th sieve - the percentage of the sieves sieved through the screen after screening through the screen as a percentage of the total sample.

Take about 1 kilogram of reinforced steel shots to be tested, and weigh the total weight in the scale of the child's precision ^ ^; cattle 0. 1 and then place it in the first-stage screen and collect the residue on the screen. The wreckage. ^ It is weighed on the balance, Calculating the weight percentage of the first sieve retention sieve, after which the first sieve mesh is placed in the second sieve and sieved, and the residue remaining in the second sieve is weighed again to obtain The percentage of the screening rate of the second-stage sieve, and so on, the second-stage sieve and the sieve are placed in the third-stage sieve and sieved, and the sieve residue and the sieved material of the third sieve are collected, and It is placed on the balance and the percentage of the screening rate and the total sieving rate of the third sieve is determined. The entire test can be carried out on a three-screen overlapping automatic screening machine.

Example: The size distribution of the reinforced steel pellets with a nominal size of 1.0 mm was determined.

1克称。 Each of the three standard sieves, the first sieve 0. 9 mm, the second sieve 1. 00 mm, the third sieve 1. 10 mm, and a non-screen container, the accuracy is not less than 0. 1 gram A heavy balance.

Test steps:

One kilogram of reinforced steel shots are randomly selected, and more weighted test specimens can be taken for the strengthened steel shots with larger specifications. Re-stringing clean first, second and third screens and non-porous containers on an automatic vibrating screen allows manual methods. Pour all the sampled reinforced steel shots into the first sieve, start the machine through the sieve, or manually sieve.

The residue in the first sieve, the residue in the second sieve, the residue in the third sieve and the sieve (the residue in the non-porous vessel) were weighed separately on the balance.

The weight of each of them is divided by the total weight of the initially sampled sample to obtain the weight distribution percentage.

Hardness testing method:

Randomly collect 100 pellets for inlaying, the inlay temperature is not more than 120 degrees Celsius, and after grinding, use the grinding wheel to make the exposed surface of the pellet close to the nominal diameter of the pellet. ^: After grinding the pellet with red sandpaper 。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。 0. 5 kg), pellet size 0. 5-1. 2 mm load is 9. 81 Newtons (1.0 kg), 3⁄4 pellets are measured, 20 hardness values are added and the arithmetic mean is taken, and Any test value must be within the specified range.

Durability test method:

A random sample of 500 grams of pellets and 100 grams of spare pellets from the tested pellets were placed in an Ervin tester. The Ervin test machine was set to 500 cycles. After setting a cycle test, use the nominal diameter of 0.2 mm to sort the sieve to take the pellets of the test pellets, and use the spare pellets to replenish the lost pellets, and then continue the cycle test until the loss pills. The amount of grain a reached 100 g, and the number of revolutions of 100 g of the weight loss was estimated to be durability.

The formula for calculating durability is:

The total number of revolutions of the total number of revolutions is one [(500 ÷ last cycle loss weight) X (total loss total weight - 100)] Example: Sampling _n 3⁄4 500 and backing 100 g, setting a cycle of every 500 rpm, when the total weight loss exceeds 100 g, a total of nine cycles, counting 4500 rpm, the last cycle loss is 25 gram, the final loss total weight For 118. 6 grams, calculate the number of revolutions that have been transferred when the chemical composition has just lost 100 grams, which not only enhances the durability of the steel shot.

450— [ (500+25) X ( 118. 6-100) ]

=4500— 20X 18. 6

=4500-372

=4128

Namely: 4128 is the durability of the sample

Finally, the relevant data of the finished product is as follows:

Reinforced steel shot

Carbon (0 0.75-0.80%

Manganese (Mn) 0.48-0.58%

Silicon (Si) 0.22-0.26%

Sulfur (S) 0.001-0.006%

Phosphorus (P) 0.011-0.015%

Iron (Fe), which is iron (Fe), average hardness

640 HV ±30 HV

(Measured under load) Hardness deviation Maximum deviation range is ±25HV Durability

Minimum density

=7.8 g / cm3

(Measured by alcohol replacement method)

Particle difference Maximum deviation range soil 0. 02 mm

Claims

Rights request

1. A reinforced steel shot, characterized in that the weight percentage composition is: carbon 0.75~0.80%, .0.48-0.58%, silicon 0.22~0.26%, sulfur 0.001~0.006%, phosphorus 0.011~0.015%, balance For iron and inevitable impurities.

A reinforced steel shot according to claim 1, wherein the average hardness measured under the load of the reinforced steel pellet is 640 HV soil 30 HV.

A reinforced steel shot according to claim 2, wherein the reinforced steel shot has a hardness deviation range of ±25 HV.

A method of preparing a reinforced steel shot according to claim 1, wherein: the method for preparing the reinforced steel shot is:

Selecting a material, drawing, cutting, screening, and testing,

The method according to claim 4, characterized in that: the material selection is a carbon spring in which the ratio of the elemental composition is the same as that of the finished reinforced steel shot, and the hardness deviation is within ±50 HV of the standard hardness of the finished reinforced steel shot. The wire is used as a raw material; the wire drawing is performed 3 to 5 times, and the carbon spring wire is drawn into a cylindrical steel wire of different specifications having a diameter of 0.2 to 3 mm; the cutting is to cut the cylindrical steel wire into a uniform length. The small cylindrical section has a cutting length which is consistent with the diameter of the cylindrical steel wire; the surface rounding strengthening is performed by rounding and strengthening the cylindrical cutting section by impact rounding and impact strengthening; Dimensions require 2 to 3 screenings; the test is for hardness and durability testing.