How should 65Mn plates be heat treated?

65mn is a commonly used spring steel.

Generally quenching and medium-temperature tempering, namely:

860-880 (15-30min) normalizing.

840-860 (10-20min) oil quenching or press oil quenching; 400 (2-5h) tempering. Tissue: Tempered sostenite (martensite is still present.)

morphology); Hardness: HRC 42-46.

Isothermal quenching can also be used, i.e.:

840-860 (10-20min) After heating and insulation, quench into 280 310 molten salt (salt bath treatment) to keep warm for 1-2h, take out and clean. Tissue: Lower bainite; Hardness: HRC 40-45.

Heat treatment specifications and metallographic structure.

Heat treatment specification: quenching 830 20, oil cooled; Tempering 540 50 (30 if special needs).

Metallographic structure: Drocytes.

Delivery Status: Hot-rolled steel is delivered in heat-treated or non-heat-treated condition, and cold-drawn steel is delivered in heat-treated condition.

65mn steel plate strength, hardness, elasticity and hardenability.

Both are higher than 65 steel, with overheating sensitivity and tempering brittleness tendency, and water quenching has a tendency to form cracks. The machinability of the annealed state is acceptable, the cold deformation plasticity is low, and the weldability is poor. Leaf springs with medium loads, coil springs and spring washers with diameters of 7-20 mm.

Spring rings. High wear resistance parts, such as grinding machine spindles, spring chucks, precision machine tool screws.

Cutters, collars on spiral roller bearings, rails. Wait.

Spring steel alloy 65mn material

65mn spring steel standard:

gb/t 1222-2007

65mn spring steel numerical code:

u21653

Characteristics and scope of application of 65mn spring steel:

Manganese improves hardenability, 12mm steel oil can be hardened, the surface decarburization tendency is smaller than that of silicon steel, and the comprehensive mechanical properties after heat treatment are better than carbon steel, but there is overheating sensitivity and tempering brittleness. It is used as a variety of flat and round springs, seat cushion springs, spring springs of small sizes, and can also be used to make spring rings, valve springs, clutch springs, brake springs and cold-drawn steel wire cold-rolled coil springs.

65mn Spring Steel Chemical Composition:

Carbon C: Silicon Si:

Manganese mn:sulfur s:

Phosphorus p:

Chromium cr:

Nickel ni:

Copper cu:

Mechanical properties of 65mn spring steel:

Tensile Strength b (MPa): 980(100).

Yield Strength s (mpa): 784(80).

Elongation δ10 (8

Section shrinkage 30

Hardness: hot-rolled, 302HB; Cold Drawing + Heat Treatment, 321HB

65mn spring steel heat treatment specification and metallographic structure:

Heat treatment specification: quenching 830 20, oil cooled; Tempering 540 50 (30 if special needs).

Metallographic structure: Drocytes.

65mn spring steel delivery status:

Hot-rolled steel is delivered in heat-treated or non-heat-treated condition, and cold-drawn steel is delivered in heat-treated condition.

65mn spring steel main specifications:

65mn round bar, 65mn rolled bar, 65mn cold drawn bar, 65mn forging bar, 65mn plate, 65mn flat bar, 65mn forging, 65mn forging ring, 65mn machining parts, 65mn pipe, 65mn forging cake.

After heat treatment and cold drawing hardening, the strength of 65mn is relatively high, and it has certain flexibility and plasticity; In the same surface state and fully hardened, the fatigue limit is comparable to that of multicolored alloy springs.

65mn low-alloy round steel must have a high elastic limit and a high yield ratio to avoid permanent deformation of spring steel under high loads;

At the same time, it is also required to have good hardenability and low decarburization sensitivity, so that the elastic limit is greatly reduced; As well as good surface quality, easy processing and forming in hot and cold conditions and good heat treatment processability.

Quenching and tempering specifications: quenching temperature 830 10, oil cooling; Tempering temperature 540-10, water and oil cooling.

65MN belongs to the national standard spring steel, the implementation standard: GB T 1222-200765MN after heat treatment and cold drawing hardening, the strength is high, with a certain toughness and plasticity; With the same surface condition and full hardening, the fatigue limit is comparable to that of alloy springs. However, the hardenability is poor, and it is mainly used for springs of smaller sizes, such as pressure and speed regulating springs, force measuring springs, round and square coil springs in general machinery or springs drawn into steel wires for small machinery.

Spring washers can be made.

The chemical composition of 65mn is shown below

65mn spring steel is easy to overheat, pay attention to the heating temperature and holding time. It is recommended to heat 820 degrees and keep warm properly. Tempering temperature: 320 degrees time to be sufficient.

Hardness: 45 48hrc has good performance.

Salt bath NaCl:BaCl=3:7 or so.

The heating temperature is 820 seconds, the time is 30 seconds (mm refers to the effective thickness of the part), and the oil is cooled. The tempering temperature is 280 meters, the air furnace time is 2 hours, and the nitrate furnace time is 30 minutes (for reference only, the specific temperature and time depend on the technical requirements).

The general process is annealing at about 800 degrees, oil quenching and water cooling at 860 degrees, and tempering at medium or high temperature according to the actual requirements.

After heat treatment and cold drawing hardening, the strength of 65mn is relatively high, and it has a certain flexibility and plasticity of acacia acacia. In the same surface state and fully hardened, the fatigue limit is comparable to that of multicolored alloy springs.

65mn low-alloy round steel must have a high elastic limit and a high yield ratio to avoid permanent deformation of spring steel under high loads;

At the same time, it is also required to have good hardenability and low decarburization sensitivity, so that the elastic limit is greatly reduced; As well as good surface quality, easy processing and forming in hot and cold conditions and good heat treatment process pure friendliness.

1.Quenching heating: 810-830C° 2Cool with oil or salt water 3Tempering heating: 370-400° 4Cool with clean water. The hardness of HRC42-45 is obtained.

What is it for. Make knives or something else.

What is your product used for?

What is the required hardness?

Otherwise it's hard to tell you, there are a lot of differences.

Please give the requirements for use to determine the process.

After quenching, the hardness of 65MN can reach about HRC62. As for tempering, it depends on how much temperature you use.

(1) As a special fixture, the workpiece is heated in the furnace.

2) Place in a place where the furnace is evenly heated.

3. Together with the fixture, the oil is quenched upright and cooled to about 250 oil.

4) Keep the quenching oil temperature at 50-60

5) Immediately put into the furnace and temper.

It is possible to smoke and not burn. The heating adopts the middle and lower limit temperature, 820 degrees is preferred. The holding time is related to the amount of furnace and the way it is placed. It should be determined according to practice, and the basic burn-through shall prevail.

Hammering leveling, carried out in tempering, one is the temperature straightening effect is good, the other is the stress after calibration, which needs to be tempered to relieve stress and prevent re-deformation.

In addition, if the oil is cooled to 250 (or 200) oil, whether the tempering temperature is adjusted (appropriately reduced) should be determined by the test.

The 65mn steel circular saw blade is pre-carbonitridized with the teeth to increase the carbon and nitrogen content, and then the conventional heat treatment is carried out to improve the tempering stability of the teeth, thereby increasing the hardness and wear resistance of the teeth and improving the service life of the circular saw blade.

Heat treatment process parameters: annealing, normalizing, tempering, tempering, quenching, tempering, stress relieving tempering (cold drawn spring steel wire).

Heating temperature 810 810 680 700 810360 570 250 360

Cooling test furnace cooling, air cooling, air cooling, oil and water, air cooling, air cooling.