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Alloy tempered steel is widely used in the manufacture of various important parts of automobiles

Alloy tempered steel

Alloy tempered steel is widely used in the manufacture of various important parts of automobiles, tractors, machine tools and other machines, such as gears, axles, connecting rods, bolts and so on.Most of the tempering and tempering parts bear a variety of working loads, the stress situation is relatively complex, the requirements of high comprehensive mechanical properties, that is, with high strength and good plasticity.

(1) medium carbon: the carbon mass fraction is generally between 0.25% and 0.50%, with a majority of 0.4%;

(2) add the elements Cr, Mn, Ni, Si to improve the hardenability: these alloy elements can not only improve the hardenability, but also form the alloy ferrite, improve the strength of steel.For example, the performance of 40Cr steel after tempering is much higher than that of 45 steel.

(3) add elements to prevent the second type of tempering brittleness: alloy tempered steel containing Ni, Cr and Mn, the second type of tempering brittleness is easy to occur when tempering at high temperature and cooling slowly.Adding Mo and W to steel can prevent the second type of tempering brittleness, and its appropriate content: the mass fraction of Mo is 0.15% ~ 0.30%, or the mass fraction of W is 0.8% ~ 1.2%.

At present, the most widely used alloy tempered steel is 4140,4340,8620, their basic information is as follows

Heat Treatment of SAE 4140 Alloy tempered steel

• ASTM 4140 Steel Annealing

Slowly heat to 800～8500 ºC, keep enough time, ensure heat thoroughly. then cooling in furnace to 480 ºC, then cool in air. After annealing, the hardness 92 HBS Max.

• AISI 4140 Steel Hardening & Quenching

4140 Steel is usually used at 18-22 HRc, If needs, AISI 4140 alloy steel can be hardened or Quenching by cold work. Quenching medium: oil

• Tempering Of ASTM 4140 Alloy tempered steel

/ ℃ tempering temperature: 205 ~ 649°C.

After tempering hardness HRC: 18-25 HRC.

Heat Treatment of SAE 8620 Alloy Steel

• Annealing of 8620 Alloy tempered steel

Slowly heated to 850 ℃ and allow enough times, let the steel to be thoroughly heated, Then cool slowly in the furnace. The 8620 alloy steel will get MAX 250 HB （Brinell hardness）.

• Hardening of 8620 Alloy structural steel

Heated slowly to 880-920°C, Then after adequate soaking at this temperature quench in oil. Temper as soon as tools reach room temperature.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

C45 quenched and tempered steel

C45 quenched and tempered steel

C45 steel is carbon structure steel, hot and cold processing performance is good, mechanical performance is better, and low price, wide source, so it is widely used.Its biggest weakness is the hardenability is low, large cross section size and high requirements of the workpiece is not suitable.

C45 steel quenching temperature in A3+(30~50) ℃

It is generally taken upper limit.The high quenching temperature can accelerate the heating speed, reduce the surface oxidation, and improve the efficiency.In order to make the austenite of the workpiece uniform, it needs enough time for insulation.If the actual furnace load is large, it is necessary to appropriately extend the insulation time.

Otherwise, the phenomenon of insufficient hardness may occur due to uneven heating.However, if the insulation time is too long, the grain size will also appear, serious defects of oxidation and decarburization, affecting the quenching quality.

heating and holding time should be extended by 1/5.

Because C45 steel hardenability is low, so should use cooling rate of large 10% brine solution.After the workpiece enters the water, it should be quenched thoroughly, but not cold. If the workpiece cools thoroughly in the brine, it may cause the workpiece to crack. This is because when the workpiece cools to about 180℃, the austenite rapidly changes to martensite, resulting in excessive tissue stress.Therefore.

When the quenching workpiece quickly cold to the temperature of the region, should take a slow cooling method.Because the water outlet temperature is difficult to grasp, must operate by experience, when the shaking of the workpiece in the water stops, the water outlet air cooling (such as oil cooling is better).In addition, the workpiece into the water should not be static. It should be in accordance with the geometric shape of the workpiece, regular movement.Static cooling medium plus stationary workpiece, resulting in uneven hardness, uneven stress and workpiece deformation, even cracking.

Hardness of C45 steel quenched

Hardness of C45 steel quenched parts should reach hrc56-59, and the section may be lower, but not lower than HRC48, otherwise, it means that: the workpiece has not been completely quenched, sostenite and even ferrite may appear in the tissue, which is still retained in the matrix through tempering, so as to reach the purpose of tempering.The tempering temperature of 45 steel after quenching is usually 560~600℃, and the hardness is HRC22~34.

Because the purpose of tempering is to obtain comprehensive mechanical properties, the hardness range is relatively wide.But the drawing has the hardness request, must adjust the tempering temperature according to the drawing request, in order to ensure the hardness.If some shaft parts require high strength, high hardness requirements;And some gear, with keyway shaft parts, because after conditioning, but also milling, insert processing, hardness requirements are lower.

About tempering insulation timeaccording to the hardness requirements and the size of the workpiece, we believe that the hardness after tempering depends on the tempering temperature, and the tempering time is not relevant, but must be back through, generally the tempering insulation time of the workpiece is always more than an hour.

The commonly used alloy tempered steels are divided into 4 categories according to hardenability and strength:

(1) quenched steel with low hardenability;

(2) quenched tempered steel;

to be continued

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

Tempered steel, generally refers to the carbon content in 0.3-0.6% of medium carbon steel.

1 introduction

The so-called tempered steel, generally refers to the carbon content in 0.3-0.6% of medium carbon steel.Generally, the parts made of this kind of steel are required to have good comprehensive mechanical properties, that is, to maintain a high strength and have good plasticity and toughness, people often use tempering treatment to achieve this purpose, so people used to call this kind of steel tempering steel.Tempered steel is widely used in the structural parts of all kinds of machines.

Quenched martensite in the temperature range of 500~650℃.After tempering, the strength, plasticity and toughness of the steel have a good match.The composition of tempered steel is carbon 0.25% ~ 0.5% carbon steel or low alloy steel and medium alloy steel.Tempered steel is widely used in the structural parts of all kinds of machines.The most widely used quenched steels are chromium quenched steels (such as 40Cr, 40CrSi), chrome-manganese quenched steels (such as 40CrMn), chrome-nickel quenched steels, (such as 40CrNiMo, 37CrNi3A), boron-containing quenched steels, etc.

2 performance characteristics

In addition to the general metallurgical low and high power structure requirements.the main mechanical properties of steel,and the cold brittle transition temperature.fracture toughness and fatigue resistance, which are closely related to the reliability.Under specific conditions, it is also required to have wear resistance, corrosion resistance and certain heat resistance.Due to the use of high temperature tempering,the stress in the steel can be completely eliminated, the hydrogen embrittlement failure tendency of steel is small, the notch sensitivity is low, the brittle failure resistance is large.

Most tempered steel are of medium carbon alloy construction with yield strength (0.2) of 49-1200 mpa.It is a low carbon alloy structural steel with a yield strength (0.2) of 490-800mpa and high plasticity and toughness.A few precipitated hardened tempered steels with yield strength (0.2) up to more than 1400Mpa belong to high strength and ultra high strength steel.

to be continued.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

DC 53 steel is a good chioce for the mask mold manufacture .If you can’t choose a suitable material, the mold may be fractured.

(4) Advantages in surface hardening treatment

The surface hardness after surface hardening is higher than that of SKD11, so the mold performance can be improved.

(5) Advantages in repairing welding operations

Since the preheating and post-heating temperatures are lower than SKD11, the repair welding operation is relatively simple.

One of our clients bought the cheaper steel to make the mask mold to save the money. The mold fractured in a short period .so he loses much as the machines don’t work. so we should choose the good steel material to produce a good product. Compared with other materials,the DC53 steel is much better .it is durable.

There are some points we need to remind to fulfill the DC 53 steel application.

In the forging process of DC53 steel die material, it is necessary to control the initial forging temperature and the final forging temperature. The initial forging temperature is controlled at 1000-1200℃ and the final forging temperature is controlled at 850-900℃. After forging, it is necessary to use asbestos or dry sand for heat preservation and slow cooling, or immediately enter the box furnace with atmosphere control for annealing treatment, the annealing temperature is 830-850℃, according to the effective thickness of the mold to determine the heat preservation time, and then the furnace cold to 550℃ below before air cooling.

Otai Steel offers both technical advice and support, as well as global professional steel solution and service. Due to satisfactory reliable quality and professional service, Otai expands our market worldwide, such as UAE, Canada, Brazil, Colombia, Chile, Spain, Turkey, Algeria, Vietnam, Malaysia and so on. Welcome to consult .

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

DC 53 steel is a good chioce for the mask mold manufacture, If you can’t choose a suitable material, the mold may be fractured.

Recently, many clients bought DC 53 steel from our company. I would like to write an article about it. with the breakout of the corona-19, we need many masks to prevent the pandemic .so the mask makers have to buy more mask mold to produce the masks.

However ,which material is better for the mask manufacture? SKD11 maybe a good choice . DC 53 steel is much better if you choose this one. If you can’t choose a suitable material, the mold may be fractured.

Why many mask factory in china choose the DC 53 steel from our company? Our company not only provides the high-quality steel product but also the skills consultation.

In the process of mold design and manufacturing, the R Angle radius should be kept above 0.50mm in such parts as sharp Angle, groove and step, to avoid the risk of mold heat treatment and cracking during use due to stress concentration.

APPLICATION OF DC53 STEEL

1. Punching mold, cold forming mold, cold drawing mold
2. Forming rolls, punches

Precision stamping die

Precision blanking die for wire cutting and stamping die for various purposes

Tool for plastic deformation of difficult-to-machine materials

Cold forging, deep drawing, and boring die

other

High-speed punching punch, stainless steel plate punch

DC53  steel Practical features:

(1) Machinability and good abrasiveness.

The machinability and the abrasiveness are superior to those of the SKD11, so the processing tool has a long life and the number of processing hours is relatively low.

(2) Advantages of heat treatment

Quench hardening is higher than SKD11, so it can improve the defects of insufficient hardness during vacuum heat treatment.

(3) Advantages of online cutting processing

High-temperature tempering can reduce the residual stress and eliminate the residual Worthfield iron, which can prevent the cracking and deformation of the wire cutting process.

To be continued

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

1.2311 Mould Steel Materials could use for N95 Mask machine production . Dongguan Otai Special Steel could provide to export all over the world .

1.2311 Mould Steel Materials is a mould materials for plastic injection . it belong to the high quality medium carbon,Pre-hardness(28~34HRc) .  Cold work plastic mould steel. It no need further heat treatment. so you don’t have any worry about distortion or cracking. 2311 steel is most widely used to plastic mold material in injection plastic mould.

DIN 1.2311 tool steel, we can supply the round bar, flat bar, plate, hexagonal and square block . Diameters can be sawn to your required lengths as one offs or multiple cut pieces . Rectangular pieces can be sawn from flat bar or plate to your specific sizes . Ground tool steel bar and precision ground steel plate can be supplied, providing a quality precision finished bar to tight tolerances .

1.2311 Tool steel is a German Die steel, the steel by “super clean” production process, pre hardened, showing the height of micro pure and excellent homogeneous structure, excellent polishing and light etching engraving. After heat treatment, processing and polishing performance is good, can be carried out, and can be processed, suitable for the surface treatment of chrome, material hardness even (to 400mm thick), good toughness, good mechanical processing performance. Gold microstructure is martensite and bainite structure.

Main be applied to in zinc, aluminum, magnesium and its alloy die-casting mould ; Hot-pressing mold, all kinds of hot forging die; Metal extrusion die, die set.

So this time , we could use them for N95 mask mould  . 1.2311 Mould Steel Materials could best match with mask manufacture .

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

Otai keeps the daily storage of the SCM440 plate. It is professional material for the N95 Mask machine ,because SCM440 has good properties.

2020 is a special year for everyone because of the pandemic. All people get into a panic .we hurry up to buy the masks, then someone busy buying the Ventilators. Others made an urgent request for the tissue. However, as a member of a steel company, we are busy keeping the storage of steel. The price of steel fluctuates. We will keep the daily storage of the SCM440 plate. It is professional material for the N95 Mask machine.

We sold many 42crmo4 plates, it is a hot-selling product of Otai company. To server the customer better, we bought new equipment for cutting steel. More sizes of SCM440 are available.

We had 20 year experience of 4140 plate trade and processing ,and had trade with middle east& sounth American countries.etc.we also offer milling and graiding processing,and most of the customer will take it for automobile die.we offer three condition.NO.1,hot rolled,black surface.NO.2.Q+T,No.3,Annealed.and the Q+T hardness would be 28-32 HRC generlly.

 AISI SCM440 plate equivalent material

♦JAPAN♦ : JIS SCM440 alloy steel

♦GERMANY♦ : DIN WN-r 1.7255 / 42CrMo4 steel alloy

♦CHINA♦ : GB 42CrMo steel

♦BRITISH♦ : BS 708M40

SCM440  steel has good workability, slight processing deformation, fatigue resistance is quite good, is a medium and so on hardenable steel, SCM440 heat treatment has better strength and good comprehensive mechanical properties, good processability, yield High. The highest use temperature is 427 degrees Celsius. SCM440 strength, high hardenability, good toughness, small deformation during quenching, high creep strength and long-term strength at high temperature. It is used to manufacture forgings that require higher strength and larger quenched and tempered section than 35CrMo steel, such as large gears for locomotive traction, supercharger transmission gears, rear axles, heavily loaded connecting rods and spring clips. Petroleum deep well drills pipe joints and fishing tools below 2000m and can be used in the mold of the bending machine.

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

4140 Mold for Mask Machine direct use . The mold have machined , heat treated , for mask manufacture .

4140 Mold for mask machine provided by Otai Special Steel . Otai Special Steel promised that we reponsible for work for Anti-coronavirus . As coronavirus infected all over the world . And all Chinese are fight with them as people on the earth . We provide all kinds of steel materials use for mask machine . Such as : 4140 , 4Cr13 , Cr12MoV .

4140 alloy steel material is a high quality Quenched and Tempered Alloy Structural steel . It belong to the high quality medium carbon alloy steel, Oil Quenched & Tempered Hardenss is 28-34 HRC . 4140 Annealing delivery hardenss less than 250HB .

4140 Mold for Mask Machine finished direct use . Could exported to all over the world . If you have any demands . we can supply the round bar, steel flat bar, plate, hexagonal steel bar and square, block . 4140 alloy steel Round bar can be cut to your required lengths as one offs or multiple cut pieces . Rectangular pieces can be cut from flat bar or plate to your specific sizes. Ground tool steel bar can be supply, providing a quality precision finished bar to tight tolerances .

AISI 4140 Alloy steel material stockholders and suppliers from China-OTAI SPECIAL STEEL . we have more 16 years experience in 4140 steel plate, round bar, flat bar, square supply . AISI 4140 alloy steel is chromium, molybdenum, manganese containing low alloy steel . It has high fatigue strength, abrasion and impact resistance, toughness, and torsional strength .

DIN 4140 Tool steel is a alloy structural steel, 4140 is used for engineering structural, like high tensile shafts, bolts and nuts, gears, pinions and spindles. Locomotive traction with the big gear, supercharger drive gear, pressure vessel, rear axle, gear load of connecting rod and a spring clip,4140 can also be used to under 2000 m deep well of oil drill pipe joint and the fishing tool, and can be used for bending machine mould, etc

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

1.2738 is used as mask mold. The mask mold produced by Otai company has the good properties of cutting and embossing.

1.2738 is used as mask mold

To cope with the problem of mask shortage, many mask factories extend the demand for mask mold. However, do you know which material is a suitable one for the mask mold manufacture? 1.2738 may be the ideal one.

S136 steel and the OT718H are also a suitable material for mask mold. which part do the 1.2738 works on the mask mold manufacture .It is used as the melt spray cloth mold. melt spray cloth is the core of the mask producing. So you shall choose the right steel material for it. As we know, 1.2738 is commonly used as a tool for steel and mold steel. Our Otai company has many 1.2738 plates of steel in storage, many mask manufacturers bought the 1.2738 and s136 from our company.

Why  1.2738 steel is used as mask mold?

1.2738 is based on P20 steel. Adding 0.9% to 1.2% Ni so that its toughness, plasticity, and corrosion resistance have been significantly improved. It is a widely used international plastic mold steel. Its comprehensive mechanical properties are good, quenched high, can make a larger cross-section of steel. It has a more uniform hardness, and  polishing performance, mold surface finish is high.

When using the steel to manufacture the mold, the general first to adjust the treatment. the hardness of 28-35HRC (i.e. pre-hardened), and then by cold processing into a mold. It can be used directly. In this way, not only to ensure the use of mold performance but also to avoid heat treatment caused by mold deformation. Therefore, the steel species is suitable for the manufacture of large and medium-sized plastic molds.

The mask mold produced by Otai company has the good properties of cutting and embossing. the storage is limited, anyone wants it, please hurry up contact me.

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

How is the plastic mold steel market now? Let’s see the market demand for plastic mold steel.

Since the 1980s, the global demand for plastic mold steel has grown rapidly, and now the growth rate has slowed down. Among them, the classic steels 1.2311 and 1.2738 can meet the growing demand for a long time. In the 1990s, the focus of plastic mold steel development was not to improve quality, but to use cheaper steel as much as possible, so growth during this period was more achieved through quantity rather than quality.

However, with changes in engineering applications, those classic steel grades are increasingly unable to meet existing production requirements. These requirements mainly include:
-Mold size
-Complex design
-Hardness and uniformity
-Cleanliness level
-Polished and textured
-Better wear resistance
-Working time
-Solderability during repair

After nearly thirty years of development, the types of mold steel have increased a lot. And a substantial improvement has been made on the basis of the original steel types. The plastics mold steel have been improved by following methods.
1)Improving the metallurgical quality of steel.
2)Increasing the pre-hardening hardness, and improving the production process.
So that it could achieve the wear resistance, polishing performance, corrosion resistance, etc.
These steels are continuously developed to adapt to the production of modern plastic parts.

As the virus is spreading rapidly all over the world, now in China the machines of mask-producing orders are lined up to this June already. And the plastic mold steel material price is increasing every day because of the high consumption on this type of steel. Our OTAI Special steel exports various tool steel,alloy steel and high speed steel to more than 35 countries from Europe and America, Middle East and Asia. Our steel materials meet DIN / ASTM / EN / JIS etc different international standards.

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com