CN101736189B - High-frequency quenching gear and heating processing technology thereof - Google Patents

Abstract

The invention discloses a high-frequency quenching gear and a heating processing technology thereof. The high-frequency quenching gear is characterized in that the core has high strength and high impact toughness after high-frequency quenching, tooth surface has high hardness and high abrasion resistance, and the high-frequency quenching gear can pass a 720-hour fatigue test. The invention not only provides the proportion relationship in cast iron but also provides the heating processing technology of the cast iron. After cast, shaped and processed, the cast iron is heated by high frequency and is quickly carried out with oil quenching treatment at the temperature of 860+/-20 DEG C; the temperature of 420+/-10 DEG C is kept for 120 minutes for tempering at low temperature. After poured by the ingredient of the invention, the gear cast iron with the component has tensile strength of 764 MPa and yield strength of 572 MPa and specific elongation of 4.2%, and hardness HB 269 satisfies the QT700-2 requirements. After processed, the high-frequency quenching gear satisfies the 720-hour fatigue test after heating processing of the invention.

Description

High-frequency quenching gear and thermal treatment process thereof

Technical field

The invention belongs to the Gear Processing field, concrete is to produce a kind of high-frequency quenching gear and this thermal treatment process.

Background technology

The processing of gear is divided into the processing of tooth base, the technological processs such as precision work that the tooth base gets into mechanical workout, tooth Profile Machining, heat treatment stages, profile of tooth at first mostly.Along with the development of mechanical skill, also different thereupon to the gear hardness requirement.Process, the tooth surface is hardened to achieve the required hardness, with the quenching process development there are high-frequency quenching treatment equipment, but if the production of the teeth bear grudge accordance with the previous process, to maintain the previous tooth bear grudge the material composition, production out of the gear can not achieve our desired hardness and toughness core part.Therefore, we have to bear grudge from the tooth material component, process engineering for this to be improved.

Summary of the invention

The purpose of this invention is to provide a kind of behind high-frequency quenching the heart portion HS, high impact toughness will be arranged, the flank of tooth has high firmness again, high abrasion, and high-frequency quenching gear that will be through fatigue test in 720 hours.

The technical scheme that the present invention is adopted to achieve these goals is: a kind of high-frequency quenching gear is provided, and said high-frequency quenching gear main ingredient is Fe, comprises that also following components in weight percentage is C:3.5-3.7%; Si:2.3-2.5%; Cr:0.15-0.25%; Mn:0.3-0.5%; Cu:0.6-0.8%.

High-frequency quenching gear one preferred version of the present invention is: said high-frequency quenching gear wherein objectionable constituent and weight percent thereof is P≤0.07; S≤0.03.

The present invention provides said a kind of thermal treatment process for preparing high-frequency quenching gear: said thermal treatment process step does,

((1) is poured the metal liquid that melts in the sand mold into, make it be cast into foundry goods after, subsequent use;

(2) carry out high-frequency quenching after the processing of foundry goods that above-mentioned casting is good, heating and temperature control is at 860 ± 20 ℃;

(3) the foundry goods oil quenching after will heating, air cooling is to room temperature;

(4) foundry goods behind the oil quenching air cooling is placed in the well formula resistance furnace carries out temper, temperature is controlled at 420 ± 10 ℃, and soaking time is 120 minutes;

(5) with the foundry goods after the temper, air cooling is to room temperature.

Beneficial effect of the present invention is: want high firmness, high abrasion behind the high-frequency quenching gear flank of tooth high-frequency quenching, mainly consider Cr, Mn, Ni element, it can improve hardening capacity.Through high-frequency induction heating, heat-up rate is fast, and soaking time is extremely short, and quenching temperature is high; Superheating temperature is big, and the austenite forming core is many, is difficult for again growing up, and the surface, back of therefore quenching obtains tiny cryptocrystalline martensite; Quenching gear surface intensity is higher, and the austenite crystal refinement, and wear resistance is significantly increased again; Ni element price is higher, and Cr, Mn price are relatively low, so select Cr, Mn element for use.

Embodiment

Raw material selection QT700-2 magnesium iron improves the Cu constituent content, reduces Mn, Cr, Si content.Confirm that composition range is: C:3.50-3.70, Si:2.3-2.5.Mn:0.3-0.5, Cr:0.15-0.25, Cu:0.6-0.8, wherein objectionable constituent and weight percent thereof are: P≤0.07, S≤0.03.

According to 300 gear blanks of cast behind the above ingredient composition, the matrix detected result is following: tensile strength 764MPa, ys 572MPa, unit elongation 4.2%, hardness HB269 satisfy the QT700-2 requirement.

The above; Be merely the preferable embodiment of the present invention; But protection scope of the present invention is not limited thereto; Any technician who is familiar with the present technique field is equal to replacement or change according to technical scheme of the present invention and inventive concept thereof in the technical scope that the present invention discloses, all should be encompassed within protection scope of the present invention.

Claims (1)

1. high-frequency quenching gear, it is characterized in that: the component of said high-frequency quenching gear is C:3.5-3.7% by weight percentage; Si:2.3-2.5%; Cr:0.15-0.25%; Mn:0.3-0.5%; Cu:0.6-0.8%; Wherein objectionable constituent and weight percent thereof do, P≤0.07; S≤0.03, all the other are iron,

The thermal treatment process of said high-frequency quenching gear does,

(1) metal liquid that melts is poured in the sand mold, make it be cast into foundry goods after, subsequent use;

(2) carry out high-frequency quenching after the processing of foundry goods that above-mentioned casting is good, heating and temperature control is at 860 ± 20 ℃;

(3) the foundry goods oil quenching after will heating, air cooling is to room temperature;

(4) foundry goods behind the oil quenching air cooling is placed in the well formula resistance furnace carries out temper, temperature is controlled at 420 ± 10 ℃, and soaking time is 120 minutes;

(5) with the foundry goods after the temper, air cooling is to room temperature.