CN105671271A - Hardening and tempering process for 35CrMo steel - Google Patents

Abstract

The invention discloses a hardening and tempering process for 35CrMo steel. The hardening and tempering process is characterized by comprising the following steps that (1) the quenching temperature is 860-870 DEG C, heat preservation time is calculated according to the section size 20-25 mm/h, primary water quenching time of a workpiece is calculated in the mode that every millimeter of the diameter of the workpiece is cooled for 1-1.2 s, the time for standing in air is 10-20 s, the workpiece is cooled in water again, and then the workpiece is transferred into oil and continues to be cooled to the room temperature; and (2) the tempering temperature is 560-630 DEG C, heat preservation is conducted for 2-2.5 h, and furnace cooling is conducted at the speed of 10-15 DEG C/h. According to the hardening and tempering process for the 35CrMo steel, the comprehensive performance of the 35CrMo steel can be improved.

Description

A kind of 35CrMo steel hardening and tempering process

Technical field

The invention belongs to Technology for Heating Processing field, specifically a kind of 35CrMo steel hardening and tempering process.

Background technology

35CrMo steel carbon content chrome-molybdenum steel between 0.25%-0.60%, there is after modified higher hardness, toughness, elasticity and thermostability, there is again good quenching degree simultaneously, it is widely used on the strength member manufacturing plant equipment, its hardening and tempering process is dealt with improperly, directly influences the mechanical property of this kind of steel. The hardening and tempering process of present 35CrMo steel adopts 850 DEG C+high tempering of quenching (500-650 DEG C). But the mechanical integrated performance after prior art 35CrMo steel is modified is desirable not enough, it is badly in need of a kind of technique more reasonable, and the hardening and tempering process of the 35CrMo steel of its combination property can be improved.

Summary of the invention

It is an object of the invention to for Shortcomings part in above-mentioned technology, the present invention provides a kind of 35CrMo steel hardening and tempering process, can improve its combination property.

The technical scheme realizing the object of the invention is as follows:

A kind of 35CrMo steel hardening and tempering process, it is characterised in that its Technology for Heating Processing comprises the steps of

(1) hardening heat 860-870 DEG C, temperature retention time calculates with sectional dimension 20-25mm/h, workpiece shrend time first time presses diameter every millimeter cooling 1-1.2s and calculates, it is cooled to after the water of surface of the work is evaporated after water outlet in atmosphere, the time of staying is between 10-20s in atmosphere, again cools down in water, and the second time shrend time is primary 2-3 times, then cool down 3-5min in atmosphere, then proceed in oil and continue cool to room temperature;

(2) temperature 560-630 DEG C, insulation 2-2.5h, 10-15 DEG C/h speed stove is cold.

A kind of 35CrMo steel hardening and tempering process of the present invention, 35CrMo round steel the water-cooled time can by diameter every millimeter cool down 1-1.2s calculate, turn oil and continue cooling, 35CrMo quenching degree is good, workpiece is made to immerse in quenching media with speed faster, and make workpiece temperature drop to Ms point with the cooling rate more than critical cooling rate to be carried out below martensite transfor mation, change 35CrMo steel internal organizational structure, improve the resistance to bending fatigue of gear, anti-contact fatigue ability and intensity. The internal stress that tempering produces when eliminating quenching, and improve elongation percentage, the contraction percentage of area and toughness.

Detailed description of the invention

Below in conjunction with embodiment, the invention will be further described:

A kind of 35CrMo steel hardening and tempering process, its Technology for Heating Processing comprises the steps of

(1) hardening heat 860-870 DEG C, temperature retention time calculates with sectional dimension 20-25mm/h, workpiece shrend time first time presses diameter every millimeter cooling 1-1.2s and calculates, it is cooled to after the water of surface of the work is evaporated after water outlet in atmosphere, the time of staying is between 10-20s in atmosphere, again cools down in water, and the second time shrend time is primary 2-3 times, then cool down 3-5min in atmosphere, then proceed in oil and continue cool to room temperature;

(2) temperature 560-630 DEG C, insulation 2-2.5h, 10-15 DEG C/h speed stove is cold.

The preferred embodiment of the present invention described in detail above. Should be appreciated that those of ordinary skill in the art just can make many modifications and variations according to the design of the present invention without creative work. All technical staff in the art, all should in the protection domain being defined in the patent claims under this invention's idea on the basis of existing technology by the available technical scheme of logical analysis, reasoning, or a limited experiment.

Claims (1)

1. a 35CrMo steel hardening and tempering process, it is characterised in that its Technology for Heating Processing comprises the steps of

(1) hardening heat 860-870 DEG C, temperature retention time calculates with sectional dimension 20-25mm/h, workpiece shrend time first time presses diameter every millimeter cooling 1-1.2s and calculates, it is cooled to after the water of surface of the work is evaporated after water outlet in atmosphere, the time of staying is between 10-20s in atmosphere, again cools down in water, and the second time shrend time is primary 2-3 times, then cool down 3-5min in atmosphere, then proceed in oil and continue cool to room temperature;

(2) temperature 560-630 DEG C, insulation 2-2.5h, 10-15 DEG C/h speed stove is cold.