Connecting rod is an important part of diesel engine, which not only has high tensile and compressive strength and high fatigue skeleton, but also has enough stiffness and toughness. Usually, the connecting rod is in service in the engine in the quenched and tempered state, and its service life depends on the quality of quenching and tempering process first, and the hardness should be HB 207 ~ 289 (different diesel engine models are different); Third, magnetic flaw detection should be carried out to ensure no cracks.

The connecting rod is made of the following materials: No.45 steel (medium carbon steel), 40Cr, 42Cr (medium carbon alloy steel), 40CrMo, malleable cast iron GTS65 and/or nodular cast iron GGG70 (mostly used in gasoline engines), etc. Quenching and tempering treatment of connecting rod material is very important, and its service life depends on the quality of quenching and tempering process, that is, its metallographic structure must be fine tempering with grain size of 1 ~ 4. Connecting rods of small gasoline engines are mostly made of malleable cast iron or nodular cast iron. The hardness of the former should be 2 10-260 HBS, and the tensile strength should not be lower than 6 19 MPa. The hardness of the latter is 240-280HBS, and the tensile strength is not lower than 690MPa. Generally speaking, connecting rods made of cast iron should be surface shot peened. Metallurgical powder forging technology has been applied to practical production in Europe and America in the 1930s. With the continuous progress of technology, metallurgical powder parts have become a new forming process of metal parts. Commonly used materials HS 150TM and HS 160TM, the mechanical properties and fatigue properties of powder forged connecting rods are similar to those of forged steel connecting rods, and the tensile strength of high-strength powder forged connecting rods can reach more than 1000MPa. Non-quenched and tempered steel connecting rod materials such as 35MnVS, 49MnVS3 and 30SiMnVS6. And breaking is a processing technology of connecting rod. I won't go into details one by one.

What material is the piston connecting rod of automobile engine made of? Why use this material (need to be explained in detail)?

The connecting rod is made of medium carbon steel or alloy steel by die forging or roll forging, and then it is machined and heat treated. Reason: The connecting rod connects the piston and the crankshaft, and it is subjected to complicated force, gas pressure from the piston pin, inertia force of piston reciprocating motion, inertia moment generated by connecting rod speed change, so it is also subjected to bending moment. All the above forces change periodically, so these materials are used to ensure strength and stiffness.

What kind of connecting rod is commonly used in diesel engines?

The connecting rod of diesel engine is generally medium carbon steel, so there are many possibilities. According to the size and type of engine, heat treatment is divided into quenching and tempering. It is common that the connecting rod of some small gasoline engines is low carbon alloy steel. The heat treatment is carburizing and quenching. Other materials are basically invisible. Never seen casting. Connecting rods are usually forgings. I'm afraid the strength of powder metallurgy parts is not enough.

What material is the connecting rod tile made of?

Connecting rod tile material: aluminum, copper, lead.

Connecting rod bearing includes connecting rod upper bearing and connecting rod lower bearing, which are installed at the joint of connecting rod and crankshaft and play the role of wear resistance, connection, support and transmission. When assembling the connecting rod tile, the upper and lower marks should not be right or wrong, the tile mouth direction should not be opposite, and the screw should reach the corresponding torque.

What problems should be paid attention to in the selection of connecting rod materials and blanks?

Problems needing attention in selecting connecting rod materials;

(1) shall have certain strength and rigidity: 45# medium carbon steel, 40Cr and 45Mn medium carbon alloy steel are generally used, and some materials are nodular cast iron. Medium carbon steel or medium carbon alloy steel can be die forged by hot working, and the fiber direction of the material is better during die forging. In order to improve fatigue strength, the surface of the connecting rod is shot peened to relieve stress.

⑵ Light weight: the cross section of the connecting rod is I-shaped, so it is light in weight and has good bending and torsional strength.

Problems that should be paid attention to when selecting blanks;

1, the influence of material manufacturability on blank selection, castings require good castability of materials, forgings require good plasticity of materials, and when welding blanks, materials require good weldability.

2. The influence of the structure, shape and size of parts on the choice of blank production mode, casting can produce blank with complex shape; Blanks with complex shapes can also be welded with good quality, but the productivity is low when the batch is large; Forging can only produce blanks with simple shapes.

3. The reliability of parts performance affects the selection of blank. Castings are easy to form various defects and have poor impact toughness. Therefore, it is not suitable to use castings as blanks for parts that usually bear dynamic loads. Forgings are mostly used for important parts with high requirements on strength, impact toughness and fatigue strength, and rolled profiles are mainly used for welding, so the performance is also good.

4. The influence of mass production of parts on blank selection. When the output is large, high-precision and high-productivity blank manufacturing methods should be adopted, such as stamping, die forging and die casting. When the output is small, it is advisable to use sand casting, free forging and other single pieces, especially when the shape is complex and the size is large. The welding method has short period and low cost.

Crank connecting rod mechanism material

Crankshaft and crank on the engine are made of 45 # steel forgings or nodular cast iron, and connecting rod is generally made of 40Gr alloy structural steel.

The crank connecting rod in ordinary machinery can be made of 45 steel.

What is the connecting rod for?

In the Linkage mechanism, the two ends of the link are hinged with the driving and driven components respectively to transmit motion and force. For example, in reciprocating piston power machinery and compressors, connecting rods are used to connect pistons and cranks. Connecting rods are mostly made of steel, and the cross section of the main body is mostly circular or I-shaped, with holes at both ends. Bronze bushings or needle bearings are installed in the holes for mounting shaft pins to form hinges. Connecting rod is an important part in automobile engine. It connects the piston and the crankshaft, and its function is to convert the reciprocating motion of the piston into the rotating motion of the crankshaft, and to transfer the force acting on the piston to the crankshaft to output power. When working, the connecting rod not only bears the pressure generated by the gas in the combustion chamber, but also bears the longitudinal and transverse inertial forces. Therefore, the connecting rod works in a complicated stress state. It bears alternating tensile stress, compressive stress and bending stress. The main damage forms of connecting rod are fatigue fracture and excessive deformation. Usually, the fatigue fracture site is three high stress areas on the connecting rod. The working conditions of the connecting rod require that the connecting rod has high strength and fatigue resistance; It also needs sufficient rigidity and toughness. In the traditional connecting rod processing technology, quenched and tempered steels such as 45 steel, 40Cr or 40MnB are generally used. However, the advanced machining technology of connecting rod fracture and splitting widely used abroad requires brittleness and high hardness. Therefore, new connecting rod materials produced by German automobile enterprises are adopted, such as C70S6 high carbon microalloyed non-quenched and tempered steel, SPLITASCO series forged steel, FRACTIM forged steel and S53CV-FS forged steel. Although alloy steel has high strength, it is sensitive to stress concentration. Therefore, strict requirements should be put forward for connecting rod shape and excessive fillet, and attention should also be paid to surface processing quality to improve fatigue strength, otherwise the application of high-strength alloy steel will not achieve the expected results.

What material is the connecting rod of the printing press made of?

Forged part (40cr) material

What material is the connecting rod tile of the engine divided into several layers?

It is a sign that the manufacturer indicates the material composition, and the records used by each manufacturer are different. It has no practical significance.

The material of each part of piston connecting rod group is 10 point.

First of all, pistons are generally made of aluminum alloy, and some diesel engines also use high-grade cast iron or heat-resistant steel. The piston only bears the impact of fuel combustion and the friction of the cylinder, so it should have good thermal conductivity and wear resistance. Piston rings are usually cast with alloy cast iron. Piston pin is a hollow cylinder, generally carburized and quenched with low carbon steel and low carbon alloy steel or quenched with 45 # medium carbon steel at high frequency. When the piston connecting rod swings and the piston group reciprocates, it bears the force and inertia force of the gas transmitted by the piston pin. The magnitude and direction of these forces change periodically. Therefore, the connecting rod bears lateral loads such as compression, tension and bending, which requires the connecting rod to have high strength and hardness. Piston connecting rod is generally made of medium carbon steel or alloy steel.