For special spring properties such as good fatigue life, nonmagnetic characteristics, resistance to corrosion, elevated temperatures and drift require special considerations. leaves are heated to critical temperature in an Oil-fired hardening furnace. Usually temperature maintained is between 850℃ and 950℃.
What is a leaf spring used for?
Leaf spring. A leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles. Originally called a laminated or carriage spring, and sometimes referred to as a semi-elliptical spring or cart spring, it is one of the oldest forms of springing, appearing on carriages in England after 1750...
What is tempered leaf spring?
Tempering process involves heating of leaves below their re-crystallization temperature and then cooling them using water or air. Because leaf springs are made of relatively high quality steel, they are a favorite material for blacksmiths.
What is heat treating spring steel?
Heat treating spring steel produces the most effective elastic limit along with best fatigue properties. The surface conditions should be sound and smooth. Corrosion and decarburisation are very detrimental to fatigue strength of steel springs. Removal of the decarburised layer increases the fatigue limits.
Why is tempering required after quenching leaf spring?
After quenching the structure of leaf spring becomes very hard and this property is not required. But this process is required to set the leaves to correct radius after cambering. To remove hardness tempering is done. Tempering: Tempering is a process of heat treating, which is used to increase the toughness.
Are leaf springs heat treated?
Leaf springs are already heat-treated, ideal for absorbing shocks, but I dont't think they will have good edge retention.
How are springs heat treated?
As soon as it's been coiled, it's taken off of the shaft and dipped into oil to cool it and quickly harden it. The coiling process causes stress in the wire, which is alleviated by stress relieving – heating the spring in an oven for a specific amount of time at a set temperature and then allowing it to cool slowly.
What are typical heat treatment methods?
Heat treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve the desired result such as hardening or softening of a material. Heat treatment techniques include annealing, case hardening, precipitation strengthening, tempering, carburizing, normalizing and quenching.
Which of the heat treatment process is generally done for spring?
annealingA method for heat treatment of a coiled spring includes cold forming a coiled spring, annealing the coiled spring after the cold forming, thereby removing of residual stress generated in the cold forming, in which the annealing is performed by electric resistance heating.
Do springs need to be heat treated?
0:000:51Should you heat treat a spring? Mid-west Spring - YouTubeYouTubeStart of suggested clipEnd of suggested clipWe don't heat treat Springs typically. It's not something that's necessary what people get confusedMoreWe don't heat treat Springs typically. It's not something that's necessary what people get confused with is stress relieved Springs or wire has a memory. Once you change that memory you add stresses.
What is the tempering temperature range for spring?
The material temperature is 730°C to 800°C. Thereafter, the tempering is performed at 400°C ± 10°C while the material is subjected to stress peening at 140 Kg/mm of initial stress.
What are the five basic heat treatment process?
There are five basic heat treating processes: hardening, case hardening, annealing, normalizing, and tempering. Although each of these processes bring about different results in metal, all of them involve three basic steps: heating, soaking, and cooling. Heating is the first step in a heat-treating process.
How many types of heat treatment are there?
4 TypesWhat are the 4 Types of Heat Treating Processes? Common types of heat treating methods include annealing, hardening, quenching, and stress relieving, each of which has its own unique process to produce different results.
What are the 3 stages of heat treatment process?
Stages of Heat TreatmentThe Heating Stage.The Soaking Stage.The Cooling Stage.
What is the most important heat treatment for hardening steels?
martensite formationAnswer. The most important heat treatment for steels is martensite formation by heating steel into the austenite region and quenching.
What is normalizing heat treatment?
Normalizing heat treatment helps to remove impurities and improve ductility and toughness. During the normalizing process, material is heated to between 750-980 °C (1320-1796 °F). The exact heat applied for treatment will vary and is determined based on the amount of carbon content in the metal.
What is hardening heat treatment?
Hardening heat treatments invariably involve heating to a sufficiently high temperature to dissolve solute-rich precipitates. The metal is then rapidly cooled to avoid reprecipitation; often this is done by quenching in water or oil.
What is a leaf spring?
A leaf spring takes the form of a slender arc -shaped length of spring steel of rectangular cross-section. In the most common configuration, the center of the arc provides location for the axle, while loops formed at either end provide for attaching to the vehicle chassis. For very heavy vehicles, a leaf spring can be made from several leaves ...
How do leaf springs work?
A leaf spring can either be attached directly to the frame at both ends or attached directly at one end, usually the front, with the other end attached through a shackle, a short swinging arm. The shackle takes up the tendency of the leaf spring to elongate when compressed and thus makes for softer springiness.
Why do trampolines have leaf springs?
Leaf springs have also replaced traditional coil springs in some trampolines (known as soft-edge trampolines), which improves safety for users and reduces risk of concussion. The leaf springs are spaced around the frame as 'legs' that branch from the base frame to suspend the jumping mat, providing flexibility and resilience.
Why is it bad to use soft springs?
Because the positioning of the axle is carried out by the leaf springs, it is disadvantageous to use soft springs i.e. springs with low spring constant. Therefore, this type of suspension does not provide good riding comfort. The inter-leaf friction between the leaf springs affects the riding comfort.
What is the advantage of leaf springs over helical springs?
A further advantage of a leaf spring over a helical spring is that the end of the leaf spring may be guided along a definite path. A more modern implementation is the parabolic leaf spring. This design is characterized by fewer leaves whose thickness varies from centre to ends following a parabolic curve.
How are leaves bent?
Leaves are bent to required radius using a press. All the leaves are tested for required radius using cambering gauges. Quenching : Hot bent leaves kept in tray and quenched in oil bath to get martensite structure. Martensite is the hardest form of steel crystalline structure.
What is the fire point of quenching oil?
Fire point of quenching oil is around 200℃ and it is seen to that temperature of oil does not exceed 80℃. After quenching the structure of leaf spring becomes very hard and this property is not required. But this process is required to set the leaves to correct radius after cambering.
What is the purpose of leaf springs?
The main function of leaf springs is to provide comfort to the passengers by minimizing the vertical vibration caused by the nonuniformity of road geometry. Studies show that the desired leaf spring material should have high strength and low modulus of elasticity in the longitudinal direction [127].
What are leaf springs?
Leaf springs are a crucial part of the suspension system of a car. They consist of a number of layers of leaves with a gradation in their size, the bigger layer being on the top with each layer joined to the other. Leaf springs are directly attached to the frame, either at both ends or at one end. For the latter, the front end is attached to the frame while the other end is attached to a short swinging arm through a shackle. The main function of leaf springs is to provide comfort to the passengers by minimizing the vertical vibration caused by the nonuniformity of road geometry. Studies show that the desired leaf spring material should have high strength and low modulus of elasticity in the longitudinal direction [127]. In addition, high fatigue resistance is one of the most desired properties for leaf springs, since they carry the entire load of the vehicle and experience dynamic load under driving conditions [128]. Leaf springs are guided by the SAE J1123 standard titled Leaf Springs for Motor Vehicle Suspension—Made to Metric Units, and can be full, semi-, or quarter-elliptic with one or more leaves. Fig. 30.8 represents the mono-leaf spring [129].
What is leaf spring landing gear?
Leaf-spring Landing Gear (A) The leaf-spring landing gear, as the name implies, consists of a relatively flat but stiff cantilever beam that reacts landing loads in bending. The primary advantage of such landing gear is that it is inexpensive, stout, durable, and is relatively easy to mount to an airplane.
What is the best material for a spring of minimum volume?
Regardless of their shape or use, the best material for a spring of minimum volume is that with the greatest value of σ y 2 / E.
Can leaf springs be made from composites?
However, interest has grown in use of leaf springs made from composites meeting the desired standards while ensuring the desired properties. Many studies have been done to analyze the suitability of composite materials for leaf springs.
Do trucks have leaf springs?
Some trucks still have leaf springs, as shown in Figure 4.9 (a). On the other hand, most cars have coil springs, see Figure 4.9 (b), which are capable of greater compression than leaf springs. Coil springs, however, vary greatly in their stiffness, i.e. their ease of compression.
Do leaf springs work on passenger cars?
Although the modelling of leaf springs is now rare on passenger cars they are still fitted extensively on light trucks and goods vehicles where they offer the advantage of providing relatively constant rates of stiffness for large variations in load at the axle. The modelling of leaf springs has always been more of a challenge in an MBS environment when compared with the relative simplicity of modelling a coil spring. Several approaches may be adopted, the most common of which are shown in Figure 6.15.
Penn Electric Racing: Heat Treating the Drive Train Spindle
This past spring, Metlab assisted Penn Electric Racing by heat treating one of their critical drive train components. Penn Electric Racing is part of a colligate international competition; similar to an Indy stock car race where the teams must design … Continue reading →
Metlab Heat Treats Automobile Parts For Antiques Racing Car
Metlab, a Philadelphia based heat treatment company, recently heat treated custom fabricated leaf springs of an antique Alfa Romeo Sports Car, which were fabricated for a Pennsylvania based automobile restorer. The leaf springs, made from HR-5160 steel, were patterned after … Continue reading →
Mrhappybottms
First off I will say that this has nothing to do with knives, but it does have to do with heat treating. I am planning a project where I need to forge my own leaf spring.
dablacksmith
well the first problem is your steel ...home depo does not sell spring steel ... at least the one here does not... you will want to get a known spring steel . Then you will want a way to get the entire thing up to around 1500 degrees . then you need to quench it in a bath (i prefer oil quench) then you need a oven to temper it .
AISI 5160 Steel
AISI 5160 steel, also known as 5160 spring steel, is a high carbon chromium alloy (maximum carbon content 0.61%, chromium content 0.9%).
5160 Spring Steel Datasheet
The table below shows the AISI 5160 steel datasheet such as chemical composition, and mechanical properties.
5160 Carbon Steel Heat Treatment
Heat treatment of 5160 steel includes spheroidizing annealing, full annealing, normalizing and austenitizing.
AISI 5160 Equivalent Grade
ASTM AISI SAE 5160 carbon steel equivalent to European EN (German DIN EN, British BSI, French NF…), Chinese GB and Japanese JIS standard.
Overview
A leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles. Originally called a laminated or carriage spring, and sometimes referred to as a semi-elliptical spring, elliptical spring, or cart spring, it is one of the oldest forms of springing, appearing on carriages in France in the mid-17th century in the form of the two-part elbow spring (as the illustrated ex…
History
There are a variety of leaf springs, usually employing the word "elliptical". "Elliptical" or "full elliptical" leaf springs, patented in 1804 by the British inventor Obadiah Elliott, referred to two circular arcs linked at their tips. This was joined to the frame at the top center of the upper arc, the bottom center was joined to the "live" suspension components, such as a solid front axle. Additional suspension components, such as trailing arms, would usually be needed for this desig…
Characteristics
The two ends of a leaf spring are formed as eyes or eyelets, through which a fastener connects each end to the frame or body of the vehicle. One eye is usually fixed translationally but allowed to pivot with the motion of the spring, whereas the other eye is fastened to a hinge mechanism that allows that end to pivot as well as undergo limited translational movement. The axle is usually fastened to the middle of the spring by U-bolts.
Manufacturing process
Multi-leaf springs are made as follows
1. Pre heat treatment process:
2. Heat treatment processes:
3. Post- heat treatment processes:
4. Assembly and surface finishes:
Heat treatment
1. Heating for Hardening: Any metal, or alloy which can be hard drawn, or rolled to fairly high strength and retains sufficient ductility to form, may be used for springs, or any alloy which can be heat treated to high strength and good ductility before, or after forming may be used. For special spring properties such as good fatigue life, nonmagnetic characteristics, resistance to corrosion, elevated temperatures and drift require special considerations. leaves are heated to critical tem…
Other uses
Because leaf springs are made of relatively high quality steel, they are a favorite material for blacksmiths. In countries such as India, Nepal, Bangladesh, Philippines, Myanmar and Pakistan, where traditional blacksmiths still produce a large amount of the country's tools, leaf springs from scrapped cars are frequently used to make knives, kukris, and other tools. They are also commonly used by amateur and hobbyist blacksmiths.
See also
• Bogie
• Carriage
• Car suspension
• Coil spring
• Corvette leaf spring