8 commonly used metal materials and their characteristics

1.45——High-quality carbon structural steel, the most commonly used medium-carbon quenched and tempered steel
Main features: The most commonly used medium carbon quenched and tempered steel has good comprehensive mechanical properties, low hardenability, and is prone to cracks during water quenching. Small parts should be quenched and high temperature tempered, and large parts should be normalized.

Application examples: Mainly used to manufacture high-strength moving parts, such as turbine impellers and compressor pistons. Shafts, gears, racks, worms, etc. Pay attention to preheating of welded parts before welding and stress relief annealing after welding.

2. Q235A (A3 steel) - the most commonly used carbon structural steel

Main features: It has high plasticity, toughness, welding performance, cold stamping performance, as well as certain strength and good cold bending performance.

Application examples: Widely used in parts and welded structures with general requirements. Such as tie rods, connecting rods, pins, shafts, screws, nuts, ferrules, brackets, machine bases, building structures, bridges, etc. that are not subject to large forces.

3. 40Cr - one of the most widely used steel types, belonging to alloy structural steel

Main features: After quenching and high temperature tempering treatment, it has good comprehensive mechanical properties, low temperature impact toughness and low notch sensitivity. It has good hardenability. It can obtain high fatigue strength when oil-cooled. Parts with complex shapes can be easily processed when water-cooled. Cracks occur, the cold bending plasticity is medium, and the machinability is good after tempering or quenching and high temperature tempering, but the weldability is not good and cracks are prone to occur. It should be preheated to 100~150℃ before welding. It is generally used in the quenched and high temperature tempered state. It can also carbonitriding and high-frequency surface quenching are performed.

Application examples: After quenching and tempering, it is used to manufacture medium-speed and medium-load parts, such as machine tool gears, shafts, worms, spline shafts, ejector sleeves, etc. After quenching and tempering and high-frequency surface quenching, it is used to manufacture high-hardness, durable surfaces. Grinding parts, such as gears, shafts, spindles, crankshafts, spindles, sleeves, pins, connecting rods, screws and nuts, intake valves, etc., are used to make heavy-duty, medium-speed impact parts after quenching and medium-temperature tempering. Parts, such as oil pump rotors, sliders, gears, spindles, collars, etc., are quenched and tempered at low temperatures to make heavy-duty, low-impact, wear-resistant parts, such as worms, spindles, shafts, collars, etc., carbon The nitriding process is used to manufacture transmission parts with larger sizes and higher low-temperature impact toughness, such as shafts, gears, etc.

4.HT150—— Grey cast iron

Application examples: gear boxes, machine tool beds, boxes, hydraulic cylinders, pump bodies, valve bodies, flywheels, cylinder heads, pulleys, bearing caps, etc.
5.35——Commonly used materials for various standard parts and fasteners

Main features: Appropriate strength, good plasticity, high cold plasticity, and acceptable weldability. It can be partially upsetting and drawing in the cold state. Low hardenability, use after normalizing or quenching and high temperature tempering.

Application examples: Suitable for manufacturing small-section parts and parts that can withstand larger loads: such as crankshafts, levers, connecting rods, shackles, etc., and various standard parts and fasteners.

6. 65Mn——Commonly used spring steel

Application examples: various small-sized flat and round springs, seat springs, spring springs, spring rings, valve springs, clutch reeds, brake springs, cold-rolled coil springs, circlips, etc.

7. 0Cr18Ni9——The most commonly used stainless steel (US steel number 304, Japanese steel number SUS304)

Characteristics and applications: It is most widely used as stainless heat-resistant steel, such as food equipment, general chemical equipment, and industrial equipment.

8. H13——Commonly used die-casting molds

Used for aluminum, zinc, magnesium and alloy die casting, hot stamping dies, aluminum extrusion dies.