CN102965672A - Heat treatment method for knife board of loading machine - Google Patents

Abstract

The invention discloses a heat treatment method for a knife board of a loading machine, relating to the technical field of heat treatment. The heat treatment method is characterized by comprising the steps of preheating a knife board workpiece at 350-450 DEG C, conducting oxygen and nitrogen penetration for low-temperature chemical heat treatment at 450-550 DEG C, then implementing high-temperature austenite nitriding at 550-650 DEG C, finally conducting quenching at 200-300 DEG C, conducting high-temperature tempering at 500-600 DEG C, and conducting air cooling. According to the heat treatment method, the quality of the knife board subjected to heat treatment has the advantages of good quality, long service life, corrosion resistance, wear resistance, and reasonable hardness; and the heat treatment process is energy-saving and low in consumption.

Description

A kind of shovel loader knife plate heat treating method

Technical fieldThe present invention relates to the heat treatment technics field, specifically relate to a kind of shovel loader knife plate heat treating method.

Background technologyShovel loader is a kind of restoration in earth-rock construction machinery that is widely used in the construction projects such as highway, railway, building, water power, harbour, mine, be mainly used in the bulk materials such as shovel dress soil, sandstone, lime, coal, also can dig operation to the slight shovel of the works such as ore, pan soil.Change the outfit that different auxiliary working apparatus also can be bulldozed, the loading and unloading operation of lifting and unclassified stores such as timber.At road, particularly in Expressway Construction, shovel loader is used for that filling out of subgrade engineering dug, the gathering materials and the operation such as charging of asphalt and coagulating cement borrow.Also can push soil, scrape plane earth and draw the operations such as other machineries.The advantages such as operating speed is fast, efficient is high, maneuvering ability is good because shovel loader has, operation is light, so it becomes one of main machine of restoration in earth-rock construction in the engineering construction.

Shovel loader knife plate general requirement has higher intensity and enough toughness, wear resistancies, thermal treatment then is the effective ways that improve the mechanical propertys such as its intensity, toughness and wear resistance, in the heat treating method of existing knife plate, the ubiquity energy dissipation is large, production efficiency is lower, product life is short, needs the phenomenon of frequent.

Summary of the inventionIn view of the defective that prior art exists, the objective of the invention is to provide the knife plate quality after a kind of thermal treatment good, the life-span is long, and is corrosion-resistant, wear-resisting, and hardness is reasonable, the heat treating method of heat treatment process low energy.

For achieving the above object, the technology used in the present invention solution is: the knife plate workpiece is passed through first preheating, carry out the cryochemistry thermal treatment of cxygen nitrogen coinfiltration again; After implementing again the high temperature austenite nitriding, quench again at last tempering.

(1) preheating: the knife plate workpiece after will shaping is delivered in the preheating zone of heating system and carries out preheating, and preheating temperature is 350～450 ℃, and be 0.25～1.0min/mm warm up time.

(2) cxygen nitrogen coinfiltration: the ammonia process is purified, be heated to 450 ℃～550 ℃ by helical pipe, ammonia is through adding heat evolution nitrogen ion, in mixing tank, pass into oxygen, and temperature is remained within 450 ℃～550 ℃, and apply 0.1～0.2Pa barometric point, oxygen and nitrogen ion are around rotational flow pipeline formation eddy current is full of at a slow speed pending knife plate workpiece, after 10 hours, when temperature is down to 350 ℃～450 ℃, stops ammonia and pass into.

(3) austenitic nitriding: be warming up in 550 ℃～650 ℃ scopes, carry out austenitic nitriding, the ammonia process is purified, be heated to 550 ℃～650 ℃ by helical pipe, ammonia is through adding heat evolution nitrogen ion, treats that ammonia decomposes when obtaining the highest nitrogen concentration the high-nitrogen austenitic layer that can reach capacity.

(4) quench: then put into fast immediately heat-eliminating medium salt and cool off, be cooled in 200 ℃～300 ℃ scopes, kept 4～5 hours.

(5) tempering: control temperature high tempering in 500 ℃～600 ℃ scopes, kept 2～3 hours, again the knife plate workpiece is placed on Slow cooling in the air.

Knife plate workpiece quality after the thermal treatment of the present invention is good, and the life-span is long, and is corrosion-resistant, wear-resisting, and hardness is reasonable, and whole heat treatment process low energy is a kind of novel method with promotional value.

EmbodimentEmbodiment of the present invention is:

(1) preheating: the knife plate workpiece after will shaping is delivered in the preheating zone of heating system and carries out preheating, and preheating temperature is 350～450 ℃, and be 0.25～1.0min/mm warm up time.

(2) cxygen nitrogen coinfiltration: the ammonia process is purified, be heated to 450 ℃～550 ℃ by helical pipe, ammonia is through adding heat evolution nitrogen ion, in mixing tank, pass into oxygen, and temperature is remained within 450 ℃～550 ℃, and apply 0.1～0.2Pa barometric point, oxygen and nitrogen ion are around rotational flow pipeline formation eddy current is full of at a slow speed pending knife plate workpiece, after 10 hours, when temperature is down to 350 ℃～450 ℃, stops ammonia and pass into.

(3) austenitic nitriding: be warming up in 550 ℃～650 ℃ scopes, carry out austenitic nitriding, the ammonia process is purified, be heated to 550 ℃～650 ℃ by helical pipe, ammonia is through adding heat evolution nitrogen ion, treats that ammonia decomposes when obtaining the highest nitrogen concentration the high-nitrogen austenitic layer that can reach capacity.

(4) quench: then put into fast immediately heat-eliminating medium salt and cool off, be cooled in 200 ℃～300 ℃ scopes, kept 4～5 hours.

(5) tempering: control temperature high tempering in 500 ℃～600 ℃ scopes, kept 2～3 hours, again the knife plate workpiece is placed on Slow cooling in the air.

Claims (1)

1. shovel loader knife plate heat treating method is characterized in that: (1) preheating: the knife plate workpiece after will shaping is delivered in the preheating zone of heating system and carries out preheating, and preheating temperature is 350～450 ℃, and be 0.25～1.0min/mm warm up time;

(2) cxygen nitrogen coinfiltration: the ammonia process is purified, be heated to 450 ℃～550 ℃ by helical pipe, ammonia is through adding heat evolution nitrogen ion, in mixing tank, pass into oxygen, and temperature is remained within 450 ℃～550 ℃, and apply 0.1～0.2Pa barometric point, oxygen and nitrogen ion are around rotational flow pipeline formation eddy current is full of at a slow speed pending knife plate workpiece, after 10 hours, when temperature is down to 350 ℃～450 ℃, stops ammonia and pass into;

(3) austenitic nitriding: be warming up in 550 ℃～650 ℃ scopes, carry out austenitic nitriding, the ammonia process is purified, be heated to 550 ℃～650 ℃ by helical pipe, ammonia is through adding heat evolution nitrogen ion, treats that ammonia decomposes when obtaining the highest nitrogen concentration the high-nitrogen austenitic layer that can reach capacity;

(4) quench: then put into fast immediately heat-eliminating medium salt and cool off, be cooled in 200 ℃～300 ℃ scopes, kept 4～5 hours;

(5) tempering: control temperature high tempering in 500 ℃～600 ℃ scopes, kept 2～3 hours, again the knife plate workpiece is placed on Slow cooling in the air.