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Talking about the influence of heat treatment on the material of crossed roller bearing

Talking about the influence of heat treatment on the material of crossed roller bearing

Crossed roller bearings have excellent rotation accuracy and greatly save installation space. They are widely used in modern precision machinery and equipment. The reason why bearings have good performance is inseparable from the heat treatment process when processing their materials. Finished product usage plays a vital role. The heat treatment of bearing rings is also a key factor affecting production efficiency and finished product quality. Today, the editor will talk to you about the influence of heat treatment on bearing materials. 1. Quenching cracks There are two types of quenching cracks after bearing quenching: deep cracks and surface cracks. Deep cracks are caused by stresses related to temperature gradients; surface cracks are related to surface decarburization. Another reason for cracks is mainly due to the reduction of the brittle fracture strength of the formed martensite due to the higher quenching temperature. Increasing the quenching temperature will reduce the number of quenching cracks; ℃, can make it more stable. If it is taken out from the hot oil and cleaned immediately, it will induce cracks, and even a mixture of a small amount of water entering the quenching oil will significantly increase the risk of cracks; if the intermediate annealing is not sufficient, or the decarburized layer is not removed. Secondary quenching also increases the possibility of cracks. Surface quenching cracks caused by decarburization are largely related to the depth of the tool marks on the surface after machining, which causes stress concentration. The greater the depth of the tool marks before quenching, the longer the cracks after quenching.
Time of issue: : 2022-03-31
Characteristics of common heat treatment furnaces and introduction of refractory materials for masonry

Characteristics of common heat treatment furnaces and introduction of refractory materials for masonry

Heat treatment furnaces are used to treat metals to change the properties and organization of metals so that they have the required physical and mechanical properties. One of the main equipments in the heat treatment workshop of the heat treatment furnace stone metallurgical factory. Due to the diversity of process requirements of the metal to be processed and the differences in thermal systems and temperature systems, there are many types of heat treatment furnaces. Due to the different process requirements of the heat treatment furnace, the temperature range of the furnace is large. Generally, the furnace temperature higher than 650℃ is called high temperature heat treatment furnace; the furnace temperature lower than 650℃ is called low temperature heat treatment furnace. The commonly used refractory materials for masonry heat treatment furnaces are refractory clay bricks and clay heat insulating refractory bricks. At present, fully lined refractory heat treatment furnaces are very common. Common heat treatment furnaces include chamber heat treatment furnaces, car bottom heat treatment furnaces, roller hearth heat treatment furnaces, bell heat treatment furnaces, tower continuous annealing furnaces, pit heat treatment furnaces, chain heat treatment furnaces, etc. 1. Chamber heat treatment furnace Various types of chamber heat treatment furnaces can be used for heat treatment of small and medium-sized parts. Figure 1-25 is a chamber heat treatment furnace with an area of ​​1.59m2, which is used for annealing and quenching of parts. The fuel is coke oven gas. There are two smoke-returning combustion chambers in the lower part of the furnace, each with a burner. The maximum heating temperature of the furnace is 950°C. The main masonry materials required for the furnace: clay drill 12.9t; diatomite brick 1.1t
Time of issue: : 2022-03-31
The latest air-cooled intermediate frequency equipment is used for induction brazing, preheating before welding, and post welding heat treatment

The latest air-cooled intermediate frequency equipment is used for induction brazing, preheating before welding, and post welding heat treatment

Electromagnetic induction heating technology is highly regarded in the field of induction brazing due to its special working principle, high heating efficiency, environmental protection and other advantages. Although not all working conditions and workpieces are suitable for induction brazing, induction brazing can help enterprises Realize fast, controllable, precise, energy-saving and repeatable brazing connections, and the application fields are also expanding. For example, mining machinery, petroleum machinery, railway transportation, wind power machinery, automobile manufacturing and other industries can see induction heating equipment. . However, with the development of the economy, the prices of raw materials in all walks of life are constantly rising, especially metals and steels, resulting in higher and higher prices of induction heating equipment. Therefore, when choosing induction heating equipment, you must choose cost-effective of. If you are familiar with the induction heating equipment industry, you know that Beichen Yike is a company that has been operating for decades, and has been committed to the research of electromagnetic induction heating equipment, especially the newly developed air-cooled intermediate frequency power supply, which is worthy of everyone's attention.
Time of issue: : 2022-03-31
Welding and heat treatment of Q235B steel plate

Welding and heat treatment of Q235B steel plate

Option 1: Welding preheating, er80s-b2l welding wire, T1G backing, e8018-b2 welding rod, electrode arc welding cover, local heat treatment after welding. Option 2: er80s-b2l welding wire, T1G bottom welding, e309mo-16 welding rod, welding rod filling arc welding cover, no heat treatment after welding. 2 Preparation before welding The welding method of the test piece using the Q235B steel plate 1 welding material is based on the weldability of the Q235B steel plate and the working characteristics of the high-pressure pipeline on site. The specification is φ32525 Before welding, use an angle grinder to polish the inside and outside of the groove and the edge of the groove within 50mm to reveal the metallic luster, and then clean it with acetone. The specimen is in a horizontal fixed position with a butt gap of 4 mm. Six points should be spot welded evenly around the circumference by manual TIG welding. The fixed length of each point of the Q235B steel plate shall not be less than 20mm. Electrode model baking temperature and holding time e8018-b2300℃2he309mo-16150℃1.5h3 Welding process parameters According to the calculation formula of preheating temperature, it should be preheated according to scheme 1 before welding: to=350√ [C] -0.25℃; formula , to the preheating temperature, °C.
Time of issue: : 2022-03-31
What material is 4142H, 4142H heat treatment process

What material is 4142H, 4142H heat treatment process

Steel performance parameters ●Steel number/grade/steel grade: 4142H ●Code: H41420 ●Steel name: Steel for oil drilling ●Execution standard: ASTM A304-2016 Quenching Hardenability Alloy Steel Bar JX2534-2016-01 Xingcheng Special Steel Enterprise Standard QZ/SJ.G7308-2019 Shigang Enterprise Standard AISI American Iron and Steel Institute Standard SAE J1268-2010 steel strip standard ●Delivery status: annealed status, the specific delivery status should be indicated in the warranty book. ●Main production steel mills: Jiangyin Xingcheng, Shigang, Fushun, etc. 4142H Summary: It is a kind of medium hardenability steel. It has high strength and good comprehensive mechanical properties after heat treatment. It has good manufacturability and the maximum operating temperature can reach 420 °C. It can withstand various forces and has good mechanical properties. At the same time, it can cope with the erosion of corrosive liquids such as hydrogen sulfide and carbon dioxide contained in the environment, and has good corrosion resistance. ●4142H chemical composition range value: Note: The actual chemical composition is subject to the steel factory warranty. Carbon C: 0.39～0.46 Silicon Si: 0.15～0.35 Phosphorus P: ≤0.035 Sulfur S: ≤0.040 Manganese Mn: 0.65～1.10 Chromium Cr: 0.75～1.20 Molybdenum Mo: 0.15～0.25 4142H mechanical properties range value: Note: The actual mechanical properties are subject to the steel factory warranty. Tensile strength σb (MPa): ≥931 Yield strength σs (MPa): ≥690 Elongation δ5(%): ≥13 Section shrinkage ψ(%): ≥45 Impact energy Akv(J): ≥48(-20℃) Annealing hardness: ≤269HB Sample size: sample blank size is 100mm 4142H use: Auger collar, square kelly, hexagonal kelly, trenchless drill pipe, drill pipe sub, weighted drill pipe, drill string combination, drill collar, non-magnetic drill collar, drilling tool, drill pipe joint, drill pipe body Wait. 4142H heat treatment process: 4142H is subjected to stress such as tension, compression, torsion and bending during use, as well as the friction of the well wall, the corrosion and friction of oil, gasoline and mud. Therefore, the correct heat treatment process plays an important role in the use of 4142H steel. Heat treatment specification: Quenching: 850℃, holding time 45min, oil cooling; Tempering: 610-640℃, water cooling, air cooling; (Note: the lower the tempering temperature, the higher the tensile strength and yield strength; the lower the elongation and impact energy) Annealing: 810℃. 4142H Features: The steel used for oil drilling is generally added between the drill pipe and the drill collar when forming the drill string to prevent the sudden change of the drill string cross section and reduce the fatigue of the drill pipe. Used in directional wells, it can drill at high speed with low torque, reducing the wear and tear of the drill string, because its rigidity is smaller than that of drill collars, and the contact area with the well wall is small.
Time of issue: : 2022-03-31
High frequency heating machine to deal with defects in drill bits

High frequency heating machine to deal with defects in drill bits

When the drill bit is heat treated by a high-frequency heating machine, it is easy to cause heat treatment defects due to unqualified chemical composition, irregular operation, and improper heat treatment. 1. The hardness and deformation are very poor If the hardness is too high, the drill will be brittle, easy to crack, reduce the wear resistance of the drill, and if the deformation effect is not good, it needs to be re-heated, which will cause resource loss, and these two problems will shorten the service life of the drill. . The reason for this is that the temperature during tempering or quenching is too low or too high, and the time is too short or too long. The temperature during straightening is low, and plasticity cannot be used for straightening. Solution: We should strictly follow the correct heat treatment process specification of the high-frequency heating machine to avoid collision, and strictly control the temperature and time of the heating process.
Time of issue: : 2022-03-31
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