阅读说明：本技术 一种耐腐蚀制动蹄滚轮轴的加工工艺 (Machining process of corrosion-resistant brake shoe roller shaft ) 是由 梁宏军 于 2018-08-29 设计创作，主要内容包括：本发明公开了一种耐腐蚀制动蹄滚轮轴的加工工艺,属于机件加工技术领域,它包括以下步骤：以铬钢为原材料,按照规定尺寸下料后,依次进行退火、平头、抛丸、磷皂化处理、冷挤整形、机加工、淬火、回火、抛丸、清洗、磨床加工、废料回收,得到成品制动蹄滚轮轴。该工艺得到制动蹄滚轮轴精度高、个体间差异小,且强度性能好,使用寿命长。(The invention discloses a processing technology of a corrosion-resistant brake shoe roller shaft, belonging to the technical field of part processing and comprising the following steps: the method comprises the following steps of taking chromium steel as a raw material, blanking according to a specified size, and then sequentially carrying out annealing, flat-heading, shot blasting, phosphorization and saponification treatment, cold extrusion and shaping, machining, quenching, tempering, shot blasting, cleaning, grinding machine machining and waste recovery to obtain the finished brake shoe roller shaft. The brake shoe roller shaft obtained by the process has the advantages of high precision, small difference among individuals, good strength performance and long service life.)

1. A processing technology of a corrosion-resistant brake shoe roller shaft is characterized by comprising the following steps: the method comprises the following steps of taking chromium steel as a raw material, blanking according to a specified size, and then sequentially carrying out annealing, flat-heading, shot blasting, phosphorization and saponification treatment, cold extrusion and shaping, machining, quenching, tempering, shot blasting, cleaning and grinding machine machining to obtain the finished brake shoe roller shaft.

2. The process of claim 1 wherein said step of machining a corrosion resistant brake shoe roller shaft comprises: the annealing is carried out in an industrial quenching resistance furnace, the annealing temperature is 750-800 ℃, and the annealing time is 6-7 h.

3. The process of claim 1 wherein said step of machining a corrosion resistant brake shoe roller shaft comprises: the shot blasting refers to performing surface shot blasting treatment by using cast steel shots, and the shot blasting time is 5-6 min.

4. The process of claim 1 wherein said step of machining a corrosion resistant brake shoe roller shaft comprises: the phosphorization and saponification treatment comprises phosphorization treatment and saponification treatment, wherein the phosphorization treatment comprises the following steps: a 1: rinsing the chromium steel material subjected to surface shot blasting twice by using clear water to remove dust on the surface of the chromium steel; a 2: removing oil stains on the surface of the chromium steel material after dust removal by using deoiling agent at the temperature of 80-90 ℃; a 3: rinsing the degreased chromium steel material twice by using hot water at the temperature of 70-80 ℃ to remove the residual degreasing agent on the surface; a 4: and b, immersing the chromium steel material treated in the step a3 into a phosphating solution for phosphating, wherein the phosphating solution comprises the following components in percentage by weight: 15-20% of zinc oxide, 20-25% of zinc dihydrogen phosphate, 15-25% of nitric acid, 6-10% of citric acid, 1-3% of nickel sulfate, 1-3% of sodium molybdate and the balance of water, wherein the phosphating conditions are as follows: the total acidity is 40-60Pt, the free acidity is 7-10Pt, the acid ratio is TA/FA6-8, the accelerator is 1-3Pt, the phosphating temperature is 70-80 ℃, and the phosphating time is 10-15 min; a 5: filtering the phosphated chromium steel material with normal-temperature clear water for 20-40 s, and removing residual phosphating solution on the surface; a 6: and soaking the chromium steel material filtered by clear water in hot water of 70-80 ℃ for 40-60 s to improve the temperature of the machined part. a 7: soaking the workpiece heated by hot water into saponification liquid for saponification, wherein the saponification liquid is a water-soluble substance of sodium stearate, the mass ratio of the sodium stearate to water is 1: 8, the solution temperature is 70-80 ℃, and the soaking time is 40-60 s.

5. The process of claim 1 wherein said step of machining a corrosion resistant brake shoe roller shaft comprises: and performing cold extrusion and shaping on a high-speed cold extrusion forming machine provided with a shaping die, immediately putting the chromium steel material subjected to phosphorization and saponification treatment into a female die of the shaping die, pressing a core rod of the shaping die into the female die, and positively extruding the chromium steel material by a punch with the impact force of 300 tons through a hydraulic press to form a brake shoe roller shaft blank.

6. The process of claim 1 wherein said step of machining a corrosion resistant brake shoe roller shaft comprises: the quenching is carried out in a multi-purpose furnace, the furnace is placed in a furnace with the furnace temperature less than or equal to 300 ℃, the temperature is increased to 800-850 ℃, the temperature is kept for 0.5h, and then the temperature is quickly increased to 900-9500 ℃ for short-time heat preservation.

7. The process of claim 1 wherein said step of machining a corrosion resistant brake shoe roller shaft comprises: the tempering is carried out in an industrial tempering furnace, the tempering temperature is 200 ℃, and the tempering time is 1.5 hours.

Technical Field

The invention relates to the technical field of machining of machine parts, in particular to a machining process of a corrosion-resistant brake shoe roller shaft.

Background

The vehicle brake is an important part of the vehicle and is the key for ensuring the driving safety. Currently used vehicle brakes include drum brakes and disc brakes. The drum brake widely used in domestic trailers, semitrailers and trucks at present consists of a brake bottom plate, brake shoes, friction linings, brake shoe supporting pins, a cam shaft, a return spring, an adjusting arm, a tension spring, a roller shaft, rollers and other parts. When the brake is stepped, the cam curved surface of the cam shaft pushes the roller to open the brake shoe, and a friction lining on the brake shoe is contacted with the inner cylindrical surface of the rotating brake drum to generate a friction resistance distance to implement braking.

In the prior art, the roller shaft is complex in structure, generally made of 45# oil steel through hot forging and machining, the forging process is complex, the production efficiency is low, particularly, each surface of a part needs to be machined after forging, the machining amount is large, and the production cost of the product is high. Some factory tests adopt an extrusion process for processing, but due to the factors of unreasonable process design, overlarge deformation and the like, a large number of cracks exist on the surface of a product, and a qualified product cannot be obtained.

Disclosure of Invention

The invention aims to provide a processing technology of a corrosion-resistant brake shoe roller shaft aiming at the defects of the prior art, most surfaces of a product are directly formed after being extruded, so that the surface processing amount is small, the processing cost is reduced, and the production efficiency is improved.

The technical scheme adopted by the invention is as follows:

a processing technology of a corrosion-resistant brake shoe roller shaft comprises the following steps: the method comprises the following steps of taking chromium steel as a raw material, blanking according to a specified size, and then sequentially carrying out annealing, flat-heading, shot blasting, phosphorization and saponification treatment, cold extrusion and shaping, machining, quenching, tempering, shot blasting, cleaning and grinding machine machining to obtain the finished brake shoe roller shaft.

The annealing is carried out in an industrial quenching resistance furnace, the annealing temperature is 750-800 ℃, and the annealing time is 6-7 h.

The shot blasting refers to performing surface shot blasting treatment by using cast steel shots, and the shot blasting time is 5-6 min.

The phosphorization and saponification treatment comprises phosphorization treatment and saponification treatment, wherein the phosphorization treatment comprises the following steps:

a 1: rinsing the chromium steel material subjected to surface shot blasting twice by using clear water to remove dust on the surface of the chromium steel;

a 2: removing oil stains on the surface of the chromium steel material after dust removal by using deoiling agent at the temperature of 80-90 ℃;

a 3: rinsing the degreased chromium steel material twice by using hot water at the temperature of 70-80 ℃ to remove the residual degreasing agent on the surface;

a 4: and b, immersing the chromium steel material treated in the step a3 into a phosphating solution for phosphating, wherein the phosphating solution comprises the following components in percentage by weight: 15-20% of zinc oxide, 20-25% of zinc dihydrogen phosphate, 15-25% of nitric acid, 6-10% of citric acid, 1-3% of nickel sulfate, 1-3% of sodium molybdate and the balance of water, wherein the phosphating conditions are as follows: the Total Acidity (TA) is 40-60Pt, the Free Acidity (FA) is 7-10Pt, the acid ratio is TA/FA6-8, the accelerator (AC value) is 1-3Pt, the phosphating temperature is 70-80 ℃, and the phosphating time is 10-15 min;

a 5: filtering the phosphated chromium steel material with normal-temperature clear water for 20-40 s, and removing residual phosphating solution on the surface;

a 6: and soaking the chromium steel material filtered by clear water in hot water of 70-80 ℃ for 40-60 s to improve the temperature of the machined part.

a 7: soaking the workpiece heated by hot water into saponification liquid for saponification, wherein the saponification liquid is a water-soluble substance of sodium stearate, the mass ratio of the sodium stearate to water is 1: 8, the solution temperature is 70-80 ℃, and the soaking time is 40-60 s.

And performing cold extrusion and shaping on a high-speed cold extrusion forming machine provided with a shaping die, immediately putting the chromium steel material subjected to phosphorization and saponification treatment into a female die of the shaping die, pressing a core rod of the shaping die into the female die, and positively extruding the chromium steel material by a punch with the impact force of 300 tons through a hydraulic press to form a brake shoe roller shaft blank.

The quenching is carried out in a multi-purpose furnace, the furnace is placed in a furnace with the furnace temperature less than or equal to 300 ℃, the temperature is increased to 800-850 ℃, the temperature is maintained for 0.5h, and the temperature is quickly increased to 900-9500 ℃ for short-time heat preservation. The temperature and time of this step are important to harden the material, increase strength, and increase service life.

The tempering is carried out in an industrial tempering furnace, the tempering temperature is 200 ℃, and the tempering time is 1.5 hours. The step is a post-treatment of quenching, and after the step, the fatigue resistance, the toughness and the corrosion resistance of the material are greatly improved.

Compared with the prior art, the invention has the following remarkable advantages and beneficial effects:

(1) according to the invention, the flat head is firstly carried out after the chromium steel is blanked, the indexes of the flat head process are that the quality of each chromium steel material is equal, namely, the quality consistency among individuals is strictly ensured at the previous stage, the chromium steel materials with the same quality are directly shaped, and the steps of boring and the like on the quality of the materials are not carried out in the middle, so that the consistency of the shape and the size of the sleeve blank obtained after the shaping of the die is very high, the deviation among samples is small, the precision is high, the internal quality of the sleeve blank is uniformly distributed, the density consistency among the samples is high, and the difference among batches is small;

(2) after annealing treatment, shot blasting is firstly carried out to remove an oxide layer on the surface of the chromium steel material, and then phosphorization and saponification are carried out, so that the phosphorization effect can be greatly improved, and the formed phosphate layer has uniform thickness, smooth surface, compact combination and low possibility of falling off;

(3) the phosphating solution and the dipping treatment method thereof have the characteristics of low use temperature (70-80 ℃), short phosphating time (10-15 min) and less sediment, and after phosphating, a zinc phosphate film with the film weight of 8-10g/m2 is generated on the surface of a metal, the film is compact and uniform and has no ash hanging, the film obtained by the phosphating solution has good stability to a lubricant, and the film is most suitable for being used as a lubricating bottom film during cold heading;

(4) the quenching and tempering play a key role in the invention, and the strength, the toughness and the tensile strength of the material are greatly improved and the service life is prolonged through the synergistic effect between the quenching and tempering.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.