CN105648355A

CN105648355A - Novel bearing steel

Info

Publication number: CN105648355A
Application number: CN201410639364.4A
Authority: CN
Inventors: 璧典凯; 赵俭
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-14
Filing date: 2014-11-14
Publication date: 2016-06-08

Abstract

The invention discloses a formula of novel bearing steel, relates to a kind of novel bearing steel and belongs to the field of metal materials and bearings. In order to solve the problems that crystalline grains are coarse and matching of toughness is poor, especially meet the requirements for heavy-duty bearings, the formula of the novel bearing steel is provided. The novel bearing steel comprises, by mass, 0.12-0.18% of carbon, 0.05-0.25% of chromium, 0.001-0.005% of sulfur, 3.10-3.50% of nickel, 0.015-0.040 % of aluminum, 0.04-0.08% of vanadium, 0.5-1.0% of manganese, more than or equal to 2% of aluminum/nitrogen, less than or equal to 0.0010% of oxygen, less than or equal to 0.020% of phosphorus, and the balance Fe and inevitable impurities.

Description

A kind of novel bearing steel

Technical field

The present invention relates to a kind of novel bearing steel, belong to the field of metallic substance and bearing.

Background technology

Bearing allows the device carrying out constrained relative motion between two parts. Rolling shaft parts is contracted containing interior raceway and outer raceway and is arranged rolling part (ball or roller) between which in a large number. For long-term reliability and performance, it is important that rolling contact fatigue, abrasion and creep are had high tolerance by different part. Along with machinery manufacturing industry, particularly the developing rapidly of automobile, aviation, nuclear industry etc., improves constantly the performance requriements of bearing, as need high temperature, at a high speed, the extraordinary bearing that works under high loading, the severe condition such as anti-corrosion. For adapting to the demand of these bearings, various countries are Study and Development one batch of new steel grade with property in succession, defines the bearing materialss such as high-carbon-chromium bearing steel, carburizing bearing steel, stainless bearing steel, high-temperature bearing steel. Wherein high-carbon-chromium bearing steel, especially 52100 steel (are equivalent to the GCr15 of China), owing to over-all properties is good, produce the advantages such as easy, price is lower, are used widely. The annual turnout of high-carbon-chromium bearing steel accounts for more than the 80% of world's bearing steel ultimate production.

Although China has become bearing steel manufactures big country, but also have suitable distance from bearing steel manufacturing power, it is mainly manifested in the following aspects: (1) bearing steel kind, specification are incomplete, low-grade more, high-grade less. High quality, high-performance bearing steel kind are few. From kind aspect, not yet form the special bearing material series such as high-carbon-chromium bearing steel, carburizing bearing steel, middle carbon bearing steel, high hardenability bearing steel, stainless bearing steel, high-temperature bearing steel. The ratio of the fine work bearing steel of high-purity cleanliness is lower. (2) quality of bearing steel steel, stability are poor, and visual appearance is not good enough. (3) the Virtual production degree of bearing steel is lower. China's bearing steel is dispersed in tens enterprises and produces, and the production technique equipment of major part manufacturer does not match, and particularly the equipment of finished product operation and relevant on-line checkingi means thereof fall behind, thus restrict the raising of domestic bearing steel oeverall quality and the stable of performance. Car bearing steel, high-speed railway bearing steel, import equipment special bearing steel, part high precision, high added value and the special bearing used when special operation condition still need import.

Chinese patent 2010080041975.9, denomination of invention bearing steel. The invention provides novel bearing steel compositions and form the method for bearing. This bearing steel composition comprises: carbon 0.4 to 0.8 weight %;Nitrogen 0.1 to 0.2 weight %; Chromium 12 to 18 weight %; Molybdenum 0.7 to 1.3 weight %; Silicon 0.3 to 1 weight %; Manganese 0.2 to 0.8 weight %; And iron 78 to 86.3 weight %. The deficiency of the present invention is owing to containing more impurity in bearing steel, have impact on the high-wearing feature of bearing steel.

Chinese patent 201310163627.X, denomination of invention is a kind of carburizing bearing steel. The present invention discloses a kind of carburizing bearing steel, and its chemical element mass percentage is: carbon: 0.10-0.16%; Manganese: 0.40-0.90%; Silicon: 0.15-0.40%; Chromium: 1.30-1.80%; Nickel: 3.10-3.80%; Molybdenum: 0.02-0.09%; Aluminium: 0.015-0.040%; Nitrogen: 0.0040-0.0070%; Aluminium/nitrogen >=3; Oxygen��0.0010%; Phosphorus��0.020%; Sulphur: 0.005-0.020%; Titanium��0.0020%; Copper��0.15%; Tin��0.025%; Antimony��0.015%; Arsenic��0.030%; Surplus is Fe and inevitable impurity. This invention Problems existing often produces pore in cementation process in steel, thus the obdurability making bearing steel is difficult to satisfy the demands.

Summary of the invention

In order to meet the strict demand of bearing steel mechanical property and work-ing life. In order to solve, crystal grain is easily thick and obdurability coupling problem, particularly for satisfied heavy duty bearing, it is desirable to provide a kind of novel bearing steel formula, solves above proposed problem.

The technical solution adopted for the present invention to solve the technical problems is: (1) control oxygen level, in non-metallic inclusion, bearing fatigue life harm is maximum is oxide based inclusion, oxygen level is more high, not only cause oxide inclusion increasing number, and size increases, to the harm also just significantly aggravation of fatigue lifetime. Therefore the most direct means be exactly control steel in oxygen level but oxygen level is down to certain level, continue to reduce oxygen level the raising effect of fatigue lifetime is not obvious, so oxygen level is not more low more good, but should there is a scientific knowledge based on analysis of experiments checking. (2) reducing titanium content, titanium belongs to residual element, and content is very low, and the past does not have its Con trolling index of clear stipulaties in a standard. But research finds, the harm of titanium-type inclusion is very big, because titanium carbonitride, the inclusiones such as titanium nitride have very high rigidity, and in size and geometry in angular, thus very easily causes stress to concentrate, bring out fatigue cracking. In addition, titanium nitride is easier than oxide compound produces segregation, and therefore, present high quality bearing steel both increases the regulation to titanium content, usually requires to be less than, and advanced level can reach left and right. The life-span discreteness of high cleanliness steel and reliability oxygen level are down to or even following high cleanliness steel, and its, dispersion property can be bigger fatigue lifetime, and serious impact is to the control of reliability level sometimes. Although this is owing to the defects such as the non-metallic inclusion in steel are little, if but occurring on the work surface or in the secondary surf zone of maximum stress, bearing will be caused to occur very soon, and early fatigue peels off! This is wherein, the large size non-metallic inclusion (essence is the crack length in the fatigue damage region formed around non-metallic inclusion) of existing minute quantity, for the bearing worked under the cleaning lubricant environment being mixed into without foreign matter, major cause especially. (3) new inclusion assessment method is adopted, as extreme statistics substitutes former ASTME45 method etc., to improve process for making technology, the quantity of control non-metallic inclusion, size and distribution, especially controlling the quantity of large-sized inclusions and probability on the work surface occur, for the discreteness significantly reducing bearing life, the reliability namely improving bearing life is very effective. Except non-metallic inclusion, contact fatigue life is also very responsive to the homogeneity of structure of steel, and thick carbide is the preferential source region producing fatigue flake equally. In the high purity steel that oxygen level and oxide inclusion content are extremely low, this impact is especially outstanding. Therefore, multiple measure should be adopted to carry out refinement uniform carbon compound, such as induction stirring homogenizing (High temperature diffusion) annealing " controlled rolling and controlled cooling " controlled atmosphere continuous spheroidizing annealing etc.! Compression ratio is also the important means ensureing that carbide refinement even " improving material density " improves material mechanical performance and fatigue strength.Bearing steel billet, especially for continuously cast bloom, it is necessary to strengthens compression ratio and improves its heart defect, such as the continuously cast bloom for general carbon steel, just can meet requirement when compression ratio is about 4 times; For highquality carbon steel and alloy steel continuous casting base, minimum compression ratio is not less than 10 times.

Bearing steel novel in the present invention, its chemical element mass percentage is: carbon: 0.12-0.18%; Chromium: 0.05-0.25%; Sulphur: 0.001-0.005%; Nickel: 3.10-3.50%; Aluminium: 0.015-0.040%; Vanadium: 0.04-0.08%; Manganese: 0.5-1.0%; Aluminium/nitrogen >=2; Oxygen��0.0010%; Phosphorus��0.020%; Surplus is Fe and inevitable impurity.

Present invention employs brand-new Technology, solve the problem that prior art products performance is not up to standard, can farthest meet the requirement of high strength height durability degree bearing steel, substantially increase quality product, be the economic benefit that enterprise creates.

Embodiment

Embodiment 1: carbon: 0.15%; Chromium: 0.05%; Sulphur: 0.001%; Nickel: 3.20%; Aluminium: 0.015%; Vanadium: 0.04%; Manganese: 1.0%; Aluminium/nitrogen >=4; Oxygen��0.0010%; Phosphorus��0.020%; Surplus is Fe and inevitable impurity.

Embodiment 2: carbon: 0.18%; Chromium: 0.15%; Sulphur: 0.005%; Nickel: 3.10%; Aluminium: 0.020%; Vanadium: 0.04%; Manganese: 0.5%; Aluminium/nitrogen >=2; Oxygen��0.0010%; Phosphorus��0.020%; Surplus is Fe and inevitable impurity.

Embodiment 3: carbon: 0.16%; Chromium: 0.25%; Sulphur: 0.001%; Nickel: 3.50%; Aluminium: 0.040%; Vanadium: 0.08%; Manganese: 0.7%; Aluminium/nitrogen >=2; Oxygen��0.0010%; Phosphorus��0.020%; Surplus is Fe and inevitable impurity.

The various enforcement low alloy steel performance comparison of table 1.

Experiment shows that illustrated bearing steel has good mechanical property and fatigue strength, reduces superheated susceptivity and the decarburizing tendency of steel simultaneously.

Claims

1. a novel bearing steel, it is characterised in that: its chemical element mass percentage is: carbon: 0.12-0.18%; Chromium: 0.05-0.25%; Sulphur: 0.001-0.005%; Nickel: 3.10-3.50%; Aluminium: 0.015-0.040%; Vanadium: 0.04-0.08%; Manganese: 0.5-1.0%; Aluminium/nitrogen >=2; Oxygen��0.0010%; Phosphorus��0.020%; Surplus is Fe and inevitable impurity.

2. novel bearing steel according to claim 1, it is characterised in that: carbon: 0.15%; Chromium: 0.05%; Sulphur: 0.001%; Nickel: 3.20%; Aluminium: 0.015%; Vanadium: 0.04%; Manganese: 1.0%; Aluminium/nitrogen >=4; Oxygen��0.0010%; Phosphorus��0.020%; Surplus is Fe and inevitable impurity.

3. novel bearing steel according to claim 1, it is characterised in that: carbon: 0.18%; Chromium: 0.15%; Sulphur: 0.005%; Nickel: 3.10%; Aluminium: 0.020%; Vanadium: 0.04%; Manganese: 0.5%; Aluminium/nitrogen >=2; Oxygen��0.0010%; Phosphorus��0.020%; Surplus is Fe and inevitable impurity.

4. novel bearing steel according to claim 1, it is characterised in that: carbon: 0.16%; Chromium: 0.25%; Sulphur: 0.001%; Nickel: 3.50%; Aluminium: 0.040%; Vanadium: 0.08%; Manganese: 0.7%; Aluminium/nitrogen >=2; Oxygen��0.0010%; Phosphorus��0.020%; Surplus is Fe and inevitable impurity.