CN102534400A

CN102534400A - Steel for large-sized mechanical cutlery and heat treatment process

Info

Publication number: CN102534400A
Application number: CN2010105901646A
Authority: CN
Inventors: 张莹
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-12-16
Filing date: 2010-12-16
Publication date: 2012-07-04

Abstract

The invention provides steel for a large-sized mechanical cutlery and a heat treatment process. The steel comprises the following chemical ingredients: C, Cr and Mo alloy elements as main ingredients, and trace B element as an auxiliary ingredient. The chemical ingredient content is as follows (based on wt%): 0.25-0.40% of C, 1.50-2.00% of Si, 0.25-0.75% of Mn, not more than 0.030% of P, not more than 0.030% of S, 0.45-0.90% of Cr, 0.08-0.18% of Mo, 0.0005-0.0050% of B, and the balance of Fe and inevitable impurities. The heat treatment process comprises quenching and tempering. According to the invention, the defects of the prior art are overcome, the chemical ingredient ratio is reasonable, the heat treatment process is simple and feasible, and the comprehensive performance of the steel is excellent; and the steel not only can bear greater impact and violent collision, but also has excellent wearing performance of a wear-resistant material, and is an ideal material for manufacturing the large-sized mechanical cutlery.

Description

The big machinery cutlery is with steel and thermal treatment process

Technical field

The invention belongs to metal material field, particularly a kind of big machinery blade is with steel and thermal treatment process.

Background technology

In the industrial and agricultural production field, big machinery commonly used has dozer, shovel loader, grapple machine etc., and blade is the main working parts that constitutes whole machinery.For example, dozer in land reclamation and cultivation, water conservancy, mine, build the road, play an important role in harbour and the military engineering.Blade is the forward position knife plate of dozer, and directly shovel is gone into materials such as sandstone, earth under forceful action, and with material generation strong friction and bump, Working environment is very abominable, the quality of blade material will directly influence its work-ing life.Therefore, also quite harsh to the requirement of blade material, it not only will have higher intensity, and good abrasion resistance will be arranged.At present, this type of blade generally is to adopt high mangaenese steel to process.But research in recent years shows that because the weave construction of high mangaenese steel is an austenite, hardness is lower; Wear resistance is relatively poor, is especially standing to can not get work hardening in the short period of time under the situation of severe impact; Under the situation of the medium and small energy impact material wearing and tearing of opposing, high mangaenese steel is not wear-resisting.Thereby causing the grinding initial stage rate of wear very fast, work-ing life is shorter.

In order to solve the wear problem of shear steel, the patent No. is to disclose a kind of " material, thermal treatment and the welding process of shovel loader integral type wear-resistant cutting edge " in 200310103856.3 the document.Described abrasion-proof shovel knife edge material is homemade steel 1E921, and component content is: C 0.15-0.20, Si0.15-0.35, Mn0.95-1.30, P≤0.035, S≤0.040, Cr0.40-0.65, Mo0.25-0.35, B 0.0005-0.0030.Though the steel wear resistance of this material is better; But tensile strength is on the low side, is merely 1450Mpa, can only under less shock load, work; Be difficult to bear strong impaction and bigger load, still can not satisfy big machinery demand of practical production under various and bad working environments.

Summary of the invention

The objective of the invention is to the deficiency of prior art and provide a kind of big machinery cutlery with steel and thermal treatment process.This steel chemical composition reasonable ratio; Thermal treatment process is simple, feasible; Not only intensity is high, good toughness, and can bear bigger impact and violent bump, has good wear-resistant grinding abrasion performance; Its over-all properties is superior to existing manganese steel and the 1E921 steel of containing, and is to be used for the ideal material that big machinery is made blade.

The present invention is achieved in that

It is to be main with C, Cr, Mo alloying element that the big machinery cutlery uses the chemical ingredients of steel, the auxilliary B element that adds trace.Each component content (wt%) is: C 0.25-0.40, and Si 1.50-2.00, Mn 0.25-0.75, P≤0.030, S≤0.030, Cr 0.45-0.90, Mo 0.08-0.18, B 0.0005-0.0050, all the other are Fe and unavoidable impurities.

The proportioning of each alloying element and main effect are among the present invention:

C:C is the one of the chief elements of decision hardness of steel.If the C too high levels is prone in the tissue produce carbide network, cause fragility to increase; If C content is low excessively, can makes decrease of hardness, thereby reduce the wear resisting property of steel.

Si:Si is an element common in the steel, in steel, does not form carbide, is that the form with sosoloid is present in ferritic or the austenite, in order to the intensity that improves sosoloid in the steel and the effect of cold deformation cementation index.

Cr:Cr is the main alloy element that improves steel hardenability, and chromium and iron form continuous solid solution, form multiple carbide with carbon, can significantly improve the antioxygenation of steel, strengthens the resistance to corrosion of steel.In steel, add Cr, can effectively improve the hardening capacity of steel, strengthen matrix.

Mo:Mo can improve the hardening capacity of steel in steel, can promote bainite transformation again, can also improve the solidifiability of steel.

B:B is the relatively richer a kind of alloy of China.In steel, add the B of trace, can form dystectic boride, be adsorbed on the crystal boundary, play dispersion-strengthened action, can also improve the hardening capacity of steel simultaneously exponentially, help bainite and form with other metals such as Cr, Mo.

The present invention provides two kinds of cutleries to use Heat Treatment Of Steel technology:

When I. using under stronger shock load abrasive wear operating mode as if steel part, should choose the steel that carbon content is a lower limit, its thermal treatment process is:

Quench: 920-930 ℃, insulation 2-2.5min, shrend;

Tempering: 230-240 ℃, insulation 2-3.0min, air cooling.

Steel after this kind thermal treatment can obtain lath martensite and add the lower bainite tissue, thereby has good obdurability, can be used for bearing in the manufacturing machine spare parts of intense impact wearing and tearing, like dozer blade, shovel loader abrasion-proof shovel knife edge etc.

When II. using under general energy impact load abrasive wear operating mode as if steel part, should choose the steel that carbon content is the middle upper limit, its thermal treatment process is:

Quench: 900-910 ℃, insulation 2-2.5min, oil quenching;

Tempering: 220-230 ℃, insulation 2-3.0min, air cooling.

Steel after this kind thermal treatment has good abrasion resistance, is applicable to the spare parts of intensity abrasive wear in bearing in the manufacturing machine, like agricultural machinery blade, ploughshare etc.

The present invention has overcome the deficiency that prior art exists, and has following advantage:

1, the composition proportion of steel is reasonable, and choosing the rich boron of China, to carry out microalloying be to reduce cost, and improves the effective measure of steel obdurability;

2, Heat Treatment Of Steel technology is proper, can obtain lath martensite and add the two-way tissue of lower bainite, and its over-all properties is superior to the steel of single martensite or bainite structure;

3, the over-all properties of steel is good, and tensile strength reaches more than the 1650Mpa, is superior to the 1E921 steel, and impelling strength and high mangaenese steel compare favourably, and wear resistance is enhanced about more than once than high mangaenese steel.

Embodiment

Produce Cutlery Steel according to prescription provided by the invention and thermal treatment process, concrete chemical ingredients is listed table 1 in, and corresponding mechanical property is listed table 2 in.

Table 1 cutlery is with the chemical ingredients (wt%) of steel

Embodiment	C	Si	Mn	P	S	Cr	Mo	B
									1	0.40	1.90	0.50	0.025	0.022	0.86	0.10	0.0010
2	0.25	1.50	0.25	0.030	0.029	0.45	0.08	0.0050
									3	0.30	1.70	0.70	0.023	0.021	0.60	0.15	0.0005

Table 2 cutlery is with the mechanical property of steel

Claims

1. a big machinery cutlery is used steel, it is characterized in that, and be main with C, Cr, Mo alloying element, the auxilliary B element that adds trace; Its Chemical Composition content (wt%) is: C 0.25-0.40, and Si 1.50-2.00, Mn0.25-0.75, P≤0.030, S≤0.030, Cr 0.45-0.90, Mo 0.08-0.18, B0.0005-0.0050, all the other are Fe and unavoidable impurities.

2. use Heat Treatment Of Steel technology to the said big machinery cutlery of claim 1, it is characterized in that:

I. quench: 920-930 ℃, insulation 2-2.5min, shrend;

Tempering: 230-240 ℃, insulation 2-3.0min, air cooling;

II. quench: 900-910 ℃, insulation 2-2.5min, oil quenching;

Tempering: 220-230 ℃, insulation 2-3.0min, air cooling.