35CrMo alloy steel

35CrMo steel is an alloy steel widely used in China, mainly for various engineering projects. This steel has excellent durability and creep strength at high temperatures, as well as good impact toughness at low temperatures. It has a very wide operating temperature range and can operate normally at high temperatures up to 500°C, while at low temperatures, its operating temperature can be as low as -100°C. In addition, 35CrMo steel also has high static strength and high fatigue strength, good hardenability, not easy to overheat, small quenching deformation, moderate processing performance. However, this material also has a problem, that is, the first type of temper brittleness, which makes it poor welding performance. Therefore, before welding, it needs to be preheated to 150-400°C and heat treated to remove stress. Usually, we use this material after quenching and tempering treatment.

The application of 35CrMo alloy steel is very wide, it can be used in the manufacture of a variety of machines to withstand impact, bending and high loads of the main parts. For example, we can use it to manufacture rolling mill gears, crankshafts, connecting rods, fasteners, automotive engine spindles, bearings, engine transmission parts, large motor shafts, etc. In addition, we can use it to manufacture boiler bolts for operating temperatures below 400°C, nuts for operating temperatures below 510°C, and high pressure seamless wall thickness catheters (non-corrosive media) for chemical machinery operating temperatures between 450 and 500°C.

The mechanical properties of 35CrMo alloy steel are also excellent. Its yield strength can reach ≥835 MPa, tensile strength can reach ≥980 MPa, elongation can reach ≥12%, area reduction rate can reach ≥45%, impact absorption energy can reach ≥63 J. In addition, its Brinell hardness can reach ≤229 (annealed or high-temperature tempered steel rods), and the sample size is 25mm.

For the heat treatment specification of 35CrMo materials, we usually perform first quenching heating at 850°C (cooling medium is oil), followed by tempering heating at 600°C (cooling medium is water or oil). In addition, 35CrMo is equivalent to American ASTM, European German DIN EN, British BS EN, French NF EN, Japanese JIS and ISO.