General machinery parts manufacturer
- Commodity name： General machinery parts manufacturer
- Commodity ID： 1191888393319632896
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Quenched-and-tempered components in general-purpose machinery—such as bolts, crankshafts, and intake valves—are typically made from medium-carbon steel or medium-carbon alloy steel. These parts undergo quenching followed by high-temperature tempering to produce a microstructure of tempered sorbite, which offers excellent overall mechanical properties. For such quenched-and-tempered parts, especially those that are not further machined after tempering—for example, bolts and intake valves—it is essential to control the carbon potential during heat treatment to prevent surface decarburization, which would reduce the part’s strength. Carburized components are quite common in general-purpose machinery, particularly stamped parts, because their surfaces must have sufficient hardness when in contact with other metal components. Examples include the speed-control flyweights on speed-control gears, the pressure plates and pawls on starter pull plates, rocker arms, and speed-control caps. After carburizing, the microstructure of the speed-control flyweights consists of needle-like martensite at the surface, providing high hardness, while the core remains ferrite with a small amount of pearlite. Nitriding: Nitrogen–carbon co-diffusion involves simultaneously introducing nitrogen and carbon atoms into the component’s surface; when nitrogen diffusion predominates, the process is called nitriding, whereas the opposite is referred to as cyaniding. In general-purpose machinery, nitrided components mainly include intake and exhaust valves, valve spring seats, tappet limit plates, and camshafts, all aimed at increasing surface hardness and wear resistance. Induction heating heat treatment is based on the principle that eddy currents induced in the workpiece generate heat, thereby heating the surface, localized areas, or the entire workpiece and then rapidly cooling it. This process is categorized into high-frequency, medium-frequency, power-frequency, and ultra-high-frequency methods. Induction hardening can enhance local hardness and strength, requires short heating times, results in minimal distortion, saves energy, and produces low pollution, making it widely used. It is suitable for medium-carbon steels and medium-carbon alloy steels, such as crankshafts, small ends of intake valves, adjusting nuts, and valve tappets in general-purpose machinery. Crankshaft: It endures cyclic gas pressures, inertial forces from the crank-connecting rod mechanism, torsional and bending stresses, as well as impact loads. Moreover, in high-speed internal combustion engines, torsional vibrations also occur, leading to substantial stress concentrations. Therefore, the crankshaft must exhibit high strength, adequate impact toughness, and good resistance to bending, torsion, and fatigue, along with high wear resistance at the journal surfaces. For medium-speed internal combustion engines, quenched-and-tempered carbon or alloy steels are typically used, such as 45, 40Cr, 45Mn2, 50Mn2, as well as ductile cast iron.
Product Details
Quenched-and-tempered components in general machinery—such as bolts, crankshafts, and intake valves—are typically made from medium-carbon steel or medium-carbon alloy steel. These parts undergo quenching followed by high-temperature tempering to produce a microstructure—tempered sorbite—that exhibits excellent overall mechanical properties. For such quenched-and-tempered components, particularly those that are not further machined after tempering—such as bolts and intake valves—it is essential to control the carbon potential during the heat treatment process to prevent decarburization of the surface, which could reduce the part’s strength.
Many components in general-purpose machinery are subject to carburizing, particularly stamped parts, because their surfaces must achieve sufficient hardness when in contact with other metal components. Examples include the speed-control flyweights on speed-control gears, the pressure plates and pawls on the start-up pull plate, the rocker arms, and the speed-control caps, among others.
Metallographic structure of the speed-regulating flyweight after carburizing: the surface consists of acicular martensite with high hardness, while the core remains ferrite with a small amount of pearlite.
Nitriding: Nitrocarburizing involves the simultaneous diffusion of nitrogen and carbon atoms into the surface of a component. When nitrogen diffusion predominates, the process is referred to as nitriding; when carbon diffusion is dominant, it is called cyaniding. Common machine-component parts that undergo nitriding include intake and exhaust valves, valve spring seats, tappet limit plates, and camshafts, all aimed at enhancing surface hardness and improving wear resistance.
The principle of induction heat treatment is to utilize the heat generated by eddy currents induced in the workpiece to heat its surface, a localized area, or the entire piece, followed by rapid quenching. This process is classified into high-frequency, medium-frequency, power-frequency, and ultra-audio categories.
Induction hardening can enhance the local hardness and strength of parts, features short heating times, minimal workpiece distortion, energy savings, and reduced environmental pollution, making it widely used. It is suitable for medium-carbon steels and medium-carbon alloy steels, such as crankshafts, small-end caps of intake valves, adjusting nuts, and valve tappets in general machinery products.
Crankshaft:
It is subjected to cyclic gas pressure, inertial forces of the crankshaft–connecting rod mechanism, torsional and bending stresses, and impact loads. Moreover, in high-speed internal combustion engines, torsional vibrations also occur, which can induce substantial stresses.
It is required to have high strength, as well as adequate impact toughness, bending strength, torsional strength, and fatigue strength, along with high wear resistance at the journal.
Medium-speed internal combustion engines use quenched-and-tempered carbon steel or alloy steel, such as 45, 40Cr, 45Mn2, and 50Mn2, as well as ductile cast iron.
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Address: No. 7, Meijia Road, Nan’an District, Chongqing
Email: fenghai@cqfenghai.com
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Company Phone：023-61966749
Company email：fenghai@cqfenghai.com
Recruitment Hotline：023-61966751
Recruitment Email：zouzongze@cqfenghai.com