Metal material compound heat treatment surface strengthening method
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A technology of composite heat treatment and surface strengthening, applied in the field of heat treatment, to achieve the effect of large thickness of the infiltrated layer, ensuring the strength and hardness of the infiltrated layer, and good strength and toughness
Active Publication Date: 2020-03-31
JIANGSU UNIV
View PDF7 Cites 0 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
However, the Q-P-T process is a process for metal body materials, and there is no precedent for surface strengthening alone
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0024] (1) 40Cr compound heat treatment surface strengthening. The 40Cr sample was cleaned by hot water, then air-dried and installed in the furnace. Ammonia, methanol and a little kerosene were introduced into the furnace. The flow rate of ammonia gas was 1m 3 / min, the kerosene flow rate is 50 drops / min, the methanol flow rate is 200 drops / min, and carbonitriding is carried out at 820°C for 2 hours;
[0025] (2) Lower the furnace temperature to 720°C, and the flow rate of ammonia gas in the furnace is 3m 3 / min, the flow rate of methanol is 100 drops / min, and nitrocarburizing is carried out for 1h.
[0026] (3) After the metal workpiece comes out of the furnace, immediately quench it in a nitrate solution at 280°C and keep it warm for 5 minutes.
[0027] (4) Carry out 160 ℃ of nitrate salt solutions and keep warm for 30min then;
[0028] (5) Finally, perform aging treatment at 230°C for 4 hours.
[0029] The hardness of the obtained infiltrated layer is greater than 720H...
Embodiment 2
[0031] (1) 08F steel composite heat treatment surface strengthening process. Thin flaky 08F steel samples were cleaned and air-dried and then installed in a furnace. Ammonia, methanol and a little kerosene were introduced into the furnace. The flow rate of ammonia gas was 1m 3 / min, the kerosene flow rate is 50 drops / min, the methanol flow rate is 200 drops / min, and carbonitriding is carried out at 840°C for 1h;
[0032] (2) Cool down to 700°C for nitrocarburizing, and the flow rate of ammonia gas in the furnace is 3m 3 / min, the flow rate of methanol is 100 drops / min, and nitrocarburizing is carried out for 2h. In the last 0.5h of nitrocarburizing, the flow rate of ammonia gas is reduced to 0.5m 3 / min, in order to achieve the purpose of removing the compound layer.
[0033] (3) After being released from the furnace, the metal workpiece is subjected to 280 ° C nitrate isothermal quenching and kept for 5 minutes;
[0034] (4) Then carry out nitrate isothermal 30min at 160°...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
PUM
Property
Measurement
Unit
depth
aaaaa
aaaaa
Login to view more
Abstract
The invention belongs to the technical field of heat treatment and discloses a metal material compound heat treatment surface strengthening method. The method comprises the steps that a metal workpiece is heated to 780-900 DEG C, is subjected to carbonitriding by a certain depth and then is cooled to 650-720 DEG C and then is subjected to carbonitriding; during the later period of the carbonitriding process, a brittle compound layer in a nitriding layer is eliminated through control over a nitrogen potential; quenching is conducted, the workpiece is put into a nitrate solution of 250-300 DEG C to be subjected to isothermal quenching and heat preservation, then subjected to isothermal quenching at 120-180 DEG C and heat preservation and finally subjected to aging treatment at 220-240 DEG C. According to the method, the quenching temperature is low, deformation of metal parts is little, and the thickness of the nitriding layer is large; moreover, the surface of a non-brittle white bright layer can be obtained, and the brittleness of the nitriding layer is greatly reduced; meanwhile, after the quenching-distribution-tempering treatment, the strength and toughness of the core of a material is improved, and the strength and hardness of the nitriding layer are further improved. Besides, the metal workpiece is subjected to quenching twice, residual pressure stress is formed on the surface layer, and the anti-fatigue performance of the metal workpiece is improved.
Description
technical field [0001] The invention belongs to the technical field of heat treatment, and relates to a heat treatment process for metal material components, in particular to an effective method for strengthening the surface of medium-low carbon (low alloy) steel. Background technique [0002] As a mature chemical heat treatment process, nitriding and carburizing have been widely used in industrial production, especially for gears, shafts, thin sheets and other metal workpieces that require high surface strength and good toughness. However, the quenching heating temperature of the ordinary carburizing process is about 930°C, resulting in high quenching stress, and it is difficult to control the deformation of small and thin metal workpieces. Although the nitriding and austenitic nitrocarburizing process makes the quenching temperature below 700°C, the carburized layer is thin and brittle, which affects the surface strengthening effect. Therefore, it is of great industrial v...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to view more