40cr characteristics 40cr main purpose 40cr how to heat treatment

1. Introduction to 40cr: 40Cr steel is a medium-carbon modulated steel. Normalizing can promote the spheroidization of the structure and improve the cutting performance of the blank with a hardness of less than 160HBS. Tempering at a temperature of 550~570℃, the steel has the best comprehensive mechanical properties. The hardenability of this steel is higher than that of 45 steel, and it is suitable for surface hardening treatments such as high-frequency quenching and flame quenching.

Second, 40cr characteristics: medium carbon quenched and tempered steel, cold heading die steel. The steel is moderately priced and easy to process. After proper heat treatment, a certain degree of toughness, plasticity and wear resistance can be obtained. The normalizing section promotes the spheroidization of the structure and is suitable for surface hardening treatments such as high-frequency quenching and flame quenching.

Third, the main purpose of 40cr: half shaft and gears, shafts, worms, spline shafts, top sleeves on machine tools, etc.; after quenching and tempering at medium temperature, it is used to manufacture parts that withstand high load, impact and medium speed work, such as gears, Sleeve, shaft, main shaft, crankshaft, 182 spindle, 3666 pin, 3769 connecting rod, screw, nut, intake valve, etc. In addition, this kind of steel is suitable for manufacturing various transmission parts that undergo carbonitriding treatment, such as gears and shafts with larger diameters and good low-temperature toughness.

Four, 40cr chemical composition:

Carbon 0.37～0.45%, silicon 0.17～0.37%, manganese 0.5～0.8, chromium 0.8～1.1%

Annealing hardness: less than 207HBS

Normalizing hardness: less than 250HBS

Five, 40cr delivery status: 40Cr delivery status is delivered by heat treatment (normalizing, annealing or high temperature tempering) or without heat treatment. The delivery status should be indicated in the contract.

Six, 40cr heat treatment: quenching at 850℃, oil cooling; tempering at 520℃, water cooling, oil cooling. The surface quenching hardness of 40Cr is HRC52-60, and the flame quenching can reach HRC48-55.