CN102517499A

CN102517499A - High-strength and low-cost dilute alloy wear resistant cast steel

Info

Publication number: CN102517499A
Application number: CN2011104254821A
Authority: CN
Inventors: 郭凯成
Original assignee: 张家港市鼎力铸钢有限公司
Priority date: 2011-12-19
Filing date: 2011-12-19
Publication date: 2012-06-27

Abstract

The invention discloses a low-cost and high-strength wear resistant cast steel utilizing silicon and manganese as main alloy elements and capable of being used for manufacturing such wear resistant components as a ball mill lining plate and an excavator bucket tooth, and the like. The chemical ingredients of the cast steel and the mass percents thereof are as follows: 0.2-0.6% of C, 0.5-1.5% of Si, 0.5-1.5% of Mn, 0.5-1.5% of Cr, smaller than 0.20% of Ti, smaller than 0.20% of RE, smaller than 0.015% of B, smaller than 0.15% of Ca and smaller than 0.015% of Al; the cast steel is firstly quenched at 950+/-10 DEG C and is annealed at 200+/-10 DEG C, the tensile strength thereof is larger than 1550 MPa, the impact toughness is larger than 90 J/cm2, the fracture toughness is larger than 80 Mpa.m1/2, and the hardness thereof is larger than 52 HRC.

Description

The cheap low-alloy wear-resistant steel of a kind of HS

Technical field

The present invention relates to a kind of low-alloy wear-resistant steel; Particularly a kind of precious metal elements such as molybdenum, nickel, copper, vanadium that do not contain; With silicon, manganese, chromium is main alloy element, can make the high-strength abrasion-proof cast steel of wear resisting parts such as excavator bucket teeth, grinder hammerhead, ball grinding machine lining board.

Background technology

Fret wear is one of three big forms with the material damage that material ruptures, material corrosion is arranged side by side, and the financial loss that causes is quite surprising.According to statistics; China consumes nearly 2,300,000 tons because of wearing and tearing cause ball mills every year; Ball mill and various crusher liner plate consume nearly 500,000 tons; Nearly 900,000 tons of roll consumption, various engineering excavation machines and shovel loader bucket tooth, various wear resistant conveying pipes road, various grinder hammerhead and jaw, various grip-pad consumption are also above 500,000 tons.In all kinds of wearing and tearing; Abrasive wear occupies an important position again; In the galling total amount, account for more than 50%; Wearing and tearing are many industrial sector ubiquities such as metallurgy, mine, machinery, electric power, coal, oil, traffic, military project and become a major reason that causes equipment failure or material damage, also are to cause one of maximum problem of financial loss.

The high-abrasive material of widespread use at present mainly contains three major types: 1. high mangaenese steel; 2. low, interalloy wear resisting steel: 3. rich chromium cast iron.High mangaenese steel is since 1882 come out, and the history in existing more than 100 year becomes traditional high-abrasive material, be widely used, China in the 50-6O age in 20th century almost high mangaenese steel as omnipotent high-abrasive material.Use in the practice and find that the wear resistance of high mangaenese steel is with good conditionsi, only impacting under the situation big, that stress is high, abrasive material is hard, high mangaenese steel is just wear-resisting.And its ys is low, easily deformable.Therefore, replaced by other high-abrasive material gradually in a lot of fields.Low, interalloy wear resisting steel is to be the basis with silicon, manganese, adds chromium, molybdenum and other trace element and grows up.Its alloy system is tied to the chromium of complicated component by the simple single manganese of composition system, silicon system, chromium system, chromium manganese. manganese. and silicon. molybdenum. the polynary composite system of other trace elements.Low, interalloy wear resisting steel has better strength and toughness, and the wear resistance under low, the middle shock load is superior to high mangaenese steel, but has hardening capacity and the low deficiency of hardenability, and wear resistance is relatively poor.Contain in the rich chromium cast iron tissue and surpass 20% high firmness eutectic carbides; Have excellent abrasive, still, have that alloying element content is high, production cost is high and high-temperature heat treatment is yielding and rimose is not enough; Ordinary white cast iron and low-alloy chilled cast iron carbide hardness are low; Carbide is continuous shape and distributes, and fragility is big, is prone in the use peel off even ftracture.

In addition, the domestic and international wear-resisting alloy steel majority of developing all contains expensive alloy element such as nickel, molybdenum at present, causes the wearable cast steel cost high, and competitive power weakens.Therefore, research and development a new generation high-abrasive material to reduce galling, has important meaning to national economy.

Summary of the invention

Technical problem to be solved by this invention is: a kind of precious metal elements such as molybdenum, nickel, copper, vanadium that do not contain are provided, and are main alloy element with silicon, manganese, chromium, can make the high-strength abrasion-proof cast steel of wear resisting parts such as ball grinding machine lining board, excavator bucket teeth.

For addressing the above problem, technical scheme of the present invention is: the chemical ingredients of said cast steel and mass percent thereof are: C:0.2-0.6; Si:0.5-1.5; Mn:0.5-1.5; Cr:0.5-1.5; Ti:＜0.20; RE:＜0.20; B:＜0.015; Ca:＜0.15; Al:＜0.15.

Said cast steel is before thermal treatment, and its as-cast structure is perlite and ferritic, also contains a small amount of martensite.Under 950 ± 10 ℃, quench earlier; Again after carrying out temper under 200 ± 10 ℃; Its heat-treated sturcture of X-ray diffraction analysis is a lath martensite, under the high power transmission electron microscope, contains a large amount of nanocrystalline austenite films between said martensite lath; Its tensile strength is greater than 1550MPa, and impelling strength is greater than 90J/cm ², fracture toughness property is greater than 80Mpa.m ^1/2,, hardness is greater than 52HRC.

Beneficial effect of the present invention:

Solved at present and made wearable cast steel as main alloy element, caused the high difficult problem of wear resistance castings cost with precious metal elements such as molybdenum, nickel.Providing a kind of is main alloy element cheapness, HS, high-wear-resistant alloy cast steel with cheap silicon, manganese.

Embodiment

The invention provides a kind of is main alloy element with low price silicon, manganese etc., can make the cheap high-strength abrasion-proof cast steel of wear resisting parts such as ball grinding machine lining board, excavator bucket teeth, and the chemical ingredients of its said cast steel and mass percent thereof are: C:0.2-0.6; Si:0.5-1.5; Mn:0.5-1.5; Cr:0.5-1.5; Ti:＜0.20; RE:＜0.20; B:＜0.015; Ca:＜0.15; Al:＜0.15.Wherein, the major function that each alloy had is:

Carbon (C): carbon content is high more, and the intensity of steel and hardness value increase, and plasticity and toughness index reduce;

Silicon (Si): reinforced ferrite, improve tensile strength and ys, improve thermotolerance and solidity to corrosion, reduce plasticity and toughness;

Manganese (Mn): improve intensity, hardness and wear resistance;

Chromium (Cr): reduce the thermal conductivity of steel, improve the wear resistance of steel;

Titanium (Ti): obvious refinement cast steel crystal grain, reduce dendritic segregation, improve the intensity and the toughness of steel, improve the wear resistance of steel;

Rhenium (Re): Re adds the effect that has desulfurization, degasification in the steel; And can change the sulfuration inclusion form to alleviate its harm in steel casting; The fine particle of rhenium and liquid reactant metal generation simultaneously, the forming core effect with accelerated solidification improves the molten steel purity; The restriction dendritic segregation, the impelling strength of raising steel;

Boron (B): boron adds in the steel as trace element, can significantly improve the hardening capacity of steel, in addition, in the compound adding steel of boron and titanium, can form tiny TiB ₂, improve the intensity and the wear resistance of cast steel;

Calcium (Ca): calcium and oxygen have very big avidity, and the deoxidizing capacity of calcium is very strong, and molten steel is had good degassing effect.Calcium also has remarkable effect to inclusion in the cast steel rotten; Add an amount of calcium and can change the strip sulfide inclusion in the cast steel into globular CaS or (Ca; Mn) S is mingled with; An amount of calcium can also significantly reduce sulphur in the gathering partially of crystal boundary, and the hot-cracking resistance ten minutes was useful when calcium was cast with raising cast steel reducing cast steel fragility.

Aluminium (Al): increase the cast steel wear resisting property.

The cheap low-alloy wear-resistant steel of HS of the present invention; Under 950 ± 10 ℃, quench, after carrying out temper under 200 ± 10 ℃, its heat-treated sturcture of X-ray diffraction analysis is a lath martensite again; Under the high power transmission electron microscope; Contain a large amount of nanocrystalline austenite films between said martensite lath, its tensile strength is greater than 1550MPa, and impelling strength is greater than 90J/cm ², fracture toughness property is greater than 80Mpa.m ^1/2,, hardness is greater than 52HRC.

Announcement through above-mentioned alloy technology scheme is visible, and Medium Alloy Steel of the present invention has characteristics such as HS, high abrasion, low cost, is especially suitable for use as the wear resisting part of ball grinding machine lining board, grinder hammerhead, excavator bucket teeth and jaw crusher jaw.

Disclosed embodiment will obtain embodying and protection through claim, any according to the present invention in resulting enlightenment, among the scope that all falls into the present invention and protected.

Claims

1. the cheap low-alloy wear-resistant steel of HS is characterized in that the chemical ingredients of its said daybreak steel and mass percent thereof are: C:0.2-0.6; Si:0.5-1.5; Mn:0.5-1.5; Cr:0.5-1.5; Ti:＜0.20; RE:＜0.20; B:＜0.015; Ca:＜0.15; Al:＜0.15.

2. low-alloy abrasion-proof fish sticking its mouth out of the water steel according to claim 1 is characterized in that: said cast steel after heat treatment, its tensile strength is greater than 1550MPa, impelling strength is greater than 90J/cm ², fracture toughness property is greater than 80Mpa.m ^1/2,, hardness is greater than 52HRC.

3. low-alloy wear-resistant steel according to claim 2 is characterized in that: said heat treatment process is: said cast steel quenches under 950 ± 10 ℃ earlier, under 200 ± 10 ℃, carries out temper again.

4. according to claim 1 or 2 or 3 described low-alloy wear-resistant steels, it is characterized in that: the as-cast structure of said cast steel is perlite and ferritic, also contains a small amount of martensite.

5. according to claim 2 or 3 described non-molybdenum non-nickel high-strength abrasion-proof cast steels; It is characterized in that: said cast steel after heat treatment; Its heat-treated sturcture of X-ray diffraction analysis is a lath martensite, under the high power transmission electron microscope, contains a large amount of nanocrystalline austenite films between said martensite lath.