CN1099810A

CN1099810A - Wear-resistance steel

Info

Publication number: CN1099810A
Application number: CN 93117604
Authority: CN
Inventors: 陈希杰; 张钊; 陈韶春
Original assignee: University of Science and Technology Beijing USTB; Wuhan Iron and Steel Group Corp
Current assignee: University of Science and Technology Beijing USTB; Wuhan Iron and Steel Group Corp
Priority date: 1993-09-11
Filing date: 1993-09-11
Publication date: 1995-03-08

Abstract

This invention discloses a new anti-wear steel whose chemical composition is C 1.00-1.20%, Mn 7.00-8.00%, Cr 2.00-3.00%, Si 0.50-1.00%, N 0.01-0.15%, P<0.09%, and S<0.05%. The workpiece and tool made of this steel have good strength, plasticity, and impact toughness, and under work condition of medium and low impact loading, this steel has good work-hardening property, and its anti-wearness can exceed that of workpiece made of traditional Mn 13. This steel has simple technology in smelting, casting and heat-treatment, and further has low content of alloy element, low cost, and very good industrial application prospect and economic value.

Description

Wear-resistance steel

The present invention relates to a kind of wear resisting steel, especially nitrogenous manganese is wear resisting steel.

There are a large amount of starting material to need to carry out grinding in many industrial production sectors such as metallurgical mine, building materials, thermoelectricity through ball mill.Ball grinding machine lining board is the very big consumable accessory of consumption, the annual hundreds of thousands of ton that consumes.Usually ball grinding machine lining board adopts the Mn13 steel to make.The Mn13 steel is a traditional widely used wear resisting steel, the manganese content height of this steel, and its chemical ingredients is: C0.90～1.50%, Mn11.0～14.0%, Si0.30～1.0%, P≤0.09%, S≤0.05%.The casting of this kind steel requires it to be organized as single austenite with after use the tough processing of water back.Under the effect of thump load, viscous deformation under the Mn13 steel workpiece surface generation cold conditions, dislocation desity rolls up in the steel, piling up of dislocations and entanglement occur, and has mechanical twin to occur.Cause the work hardening of material owing to these reasons.Austenitic initial hardness is HB190～230, and work hardening layer hardness can reach HB500～800, and thin hardened layer can reach several millimeters to tens millimeters.It is very suitable on the large-size ball mill of crusher, excavator and grinding hard material that these characteristics make the Mn13 steel workpiece.But in, under the low ballistic working condition because shock load is little, the work hardening capacity of workpiece surface material is low, surface hardness often is lower than HB300～350, hardened layer is also very shallow, the wear resistance wretched insufficiency that seems.And the Mn13 steel is owing to manganese, carbon content height in the steel, the stabilization of austenite height, be difficult to occur ε ' martensite (the close-packed hexagonal martensite that deformation is brought out) during deformation, more difficult or α ' martensite (being the B.C.T. martensite that deformation is brought out) do not occur, be that martensitic being formed on only occupied very little proportion in the work hardening process, this greatly reduces the speed of work hardening, and the degree that hardness improves is also low.

Industry member has been carried out the raising wear resistance at medium and small impact load condition for this reason, the research of exploitation novel material.Experimental results show that, reduce manganese, carbon content in the Austenitic Manganese Steel, reduce austenitic stability, can promote martensitic transformation during deformation, increase the reinforcement ability of steel, make steel except effect, because the result of phase transformation has improved work hardening speed and obviously improved hardness owing to dislocation and mechanical twin.Therefore the steel grade that some low manganese carbon contents occurred is as the steel grades such as Mn8Mo, low-carbon Mn 13Mo of the U.S..But the steel grade cost that contains molybdenum is very high, and wear resistance is not greatly improved, and can not large-scale popularization use.Russian patent SU1650756 discloses a kind of wear resisting steel, its main component is C0.6～0.8%, Mn0.7～1.7%, Cr1.3～1.6%, V1.1～1.5%, Nb0.6～0.9%, Co0.3～0.7% has used alloying elements such as the vanadium more expensive than molybdenum, niobium, cobalt and content higher in steel, and cost is very high, and non-austenite structure can not guarantee the impelling strength of workpiece.Chinese patent 87100948 discloses a kind of antiwear low-manganese steel that is used to make grinding, disintegrating apparatus vulnerable part, and its main chemical compositions is C0.37～0.52%, Mn0.9～2.0%, Si0.17～0.37%.This class medium carbon low alloy steel is a martensite steel sections, poor toughness, and the resistance to shock loads ability is low, and the thermal treatment process complexity, occurs crackle easily.

The object of the invention will provide a kind of work hardening ability good exactly, and is not only wear-resisting but also higher impelling strength and intensity are arranged, and the low new steel grade of the simple cost of production technique.

To achieve these goals, proposed a kind of invention of wear resisting steel, the principal character of this steel is to contain: C1.00～1.20%, Mn7.00～8.00%, Cr2.00～3.00%, Si0.50～1.00%, N0.10～0.15%, P≤0.09%, S≤0.05%.

According to the failure analysis result to the Mn13 steel liner plate, requiring novel material must be austenitic steel, good plasticity, toughness and higher intensity, higher initial hardness and good work hardening capacity should be arranged, and production cost should not increase.So the present invention adopts the manganese of moderate content, use chromium and nitrogen as the alloying element of strengthening and improve work hardening capacity and wear resistance.Each component content determine to be based on following consideration.

Carbon is the element that promotes that austenite structure forms in manganese steel, and the solution strengthening effect of carbon improves the intensity of steel and initial hardness, thereby improves the wear resistance of steel.But carbon content surpasses the toughness that can reduce steel after 1.20%, and high-load on the other hand carbon increases stabilization of austenite and improves austenitic stacking fault energy, and is unfavorable to the work hardening ability of steel.High carbon content obtains the single-phase austenite structure difficulty that becomes when also making the tough processing of water, high-carbon content makes ε ' martensite be difficult to form the more difficult formation of α ' martensite.These all are unfavorable for improving wear resistance.Therefore carbon content can not be too high, is advisable with 1.00～1.20%.

Manganese is the element of stable austenite, reduces manganese content and helps the martensitic formation of α ', and to work hardening, it is all favourable to improve hardness and wear resistance.But manganese can not fall lowly excessively, otherwise the intensity of steel and mould, toughness reduces too much.Because nitrogen solubleness in manganese is high in iron, for making full use of the effect of nitrogen, manganese content also can not be low excessively.Take all factors into consideration the influence of various factors, determine that manganese content is 7.00～8.00%.

Nitrogen is alloying element among the present invention, though its content important role less.The main effect of nitrogen is crystal grain thinning, solution strengthening, raising intensity and impelling strength.Nitrogen helps fault, mechanical twin, α ' martensite and the martensitic formation of ε ', thereby improves work hardening capacity and wear resistance.According to experiment, the content of nitrogen is suitable in 0.10～0.15% scope.

Chromium is alloying element the most frequently used in the Austenitic Manganese Steel, and chromium in austenite, increases the intensity of steel through solid solution after the solution treatment.Add small additions of chromium in the steel and can remedy the decline that reduces the strength property that causes owing to manganese content, make the intensity of steel remain on higher level.Chromium reduces stacking fault energy in addition, helps fault, mechanical twin, α ' martensite and the martensitic formation of ε ', helps improving work hardening capacity and wear resistance.Chromium content is 2.00～3.00% among the present invention.

Other composition all is controlled in the normal ranges among the present invention.As silicon is 0.50～1.00%, objectionable constituent P≤0.09%, S≤0.05%.

The smelting of wear resisting steel of the present invention, cast are identical with conventional Mn13, but since among the present invention the manganese content of steel obviously reduce than Mn13 and contain chromium, the more carbide of formation easily in the as cast condition undertissue.Therefore the temperature of solution treatment (being the tough processing of water) will suitably improve, and its lower limit temperature is not less than 1100 ℃, is advisable with 1100～1130 ℃, improves 20～30 ℃ than the treatment temp of Mn13 steel.

Because smelting, casting, the thermal treatment process of wear resisting steel of the present invention are simple, and the alloying element content of wear resisting steel of the present invention is low, so cost is low, and (ferrochrome in the starting material is a high carbon ferro-chrome, its price is the same substantially with ferromanganese), the production of the attrition component of low gouging abrasion load condition condition has favorable industrial application prospect and high economic worth in can being widely used in.

According to test-results, the optimal components scope of wear resisting steel of the present invention is: C1.10～1.20%, Mn7.50～8.00%, Cr2.00～2.50%, Si0.50～0.70%, N0.10～0.12%, P≤0.08%, S≤0.04%.Producing the wear resisting steel of mentioned component can smelt in the most frequently used basic electric arc furnace or induction furnace.Molten steel carries out final deoxygenation with aluminium, and the add-on of aluminium is 0.10～0.15% of a molten steel weight.Foundry goods uses after the tough processing of water.

After tested, the mechanical property of wear resisting steel of the present invention is as follows:

σ0.2(MPa) σb(MPa) δ(%) ak(J/cm ²)

450～460 600～700 13～16 100～110

As seen the σ 0.2 of novel material surpasses the level (300MPa) of Mn13, and σ b is equivalent to the level (650MPa) of Mn13, and impelling strength and plasticity index are also all very high, can satisfy the needs of industrial application.Particularly novel material in, work hardening ability is fine under the low impact abrasive wear working condition, work hardening speed is fast, hardenability is high, working-surface hardness can reach HV1070, substantially exceed the wear resistance of Mn13 under the same terms, under the condition of impact abrasive of simulation ball mill, its wear weight loss is 0.38395g, and the wear weight loss of Mn13 is 0.67266g, and wear resistance has improved 75%.

Claims

1, a kind of wear resisting steel, its feature is in containing C 1.00～1.20%, and Mn 7.00～8.00%, and Cr 2.00～3.00%, and Si 0.50～1.00%, and N 0.10～0.15%, P≤0.09%, S≤0.50.

2, wear resisting steel as claimed in claim 1.The optimum range that it is characterized in that each component is: C1.10～1.20%, Mn7.50～8.00%, Cr2.00～2.50%, Si0.50～0.70%, N0.10～0.12%, P≤0.08%, S≤0.04%.