Category Archives: Blog

30CrNiMo8 Round Bar Diameter size : 20-130MM sales promotion .

OTAI SPECIAL STEEL is 30CrNiMo8 alloy steel stockholders and suppliers from china . we have more 16 years experience in 30CrNiMo8 steel round bar, plate, steel flat bar, square supply.

30CrNiMo8 alloy steel is a high quality Quenched and Tempered Alloy Structural steel . It belong to the high quality medium carbon, Oil Quenched & Tempered Hardenss is 28-34 HRc.4340 Annealing delivery hardenss less than 250HB .

30CrNiMo8 Round Bar is a alloy structural steel,  30CrNiMo8 Round Bar is used for engineering structural . Used as require good toughness, high strength, as well as the important conditioning of large size, heavy machinery such as high load of axial .  turbine shaft, larger than 250 mm in diameter of helicopter rotor shaft, turbojet engine turbine shaft, blade, high load of transmission parts, fasteners of the crankshaft .

30CrNiMo8 Round Bar is Gear, etc.; Can also be used for operating temperature over 400 ℃ of rotor shaft and blade, etc.; And after nitriding processing can also be used to make special performance requirements of the important parts, after low temperature tempering or can be used for ultra-high strength steel after isothermal quenching .

30CrNiMo8 Round Bar and flat sections can be cut to your required sizes. AISI 4340 tool steel ground bar can also be supplied, providing a high quality tool steel precision ground tool steel bar to your required tolerances. ASTM 4340 steel is also available as Ground Flat Stock / Gauge Plate, in standard and nonstandard sizes .

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

S136 steel sold by Otai company is adorable by the shoe factory.

Recently, the global economy is affected by the pandemic, I am wondering our factory will not as busy as before. However, my boss told us our colleagues work till night. As a company exports steel all over the world,Otai also sells steel in the Chinese mainland, we have many loyal customers. Although it is a hard time for every company .many customers still buy the s136 steel from our company, because they trust us, the quality of our product is assured.

Almost the factories have already resumed production. Many customers producing the shoes buy S136 steel from our company to build to mold. Why they buy the s136 steel as the shoe mold. I would like to share some details about it with you.

There are many advantages to the s136 .the prominent one is it has good corrosion resistance. It costs less even it is used for a long time. also, it keeps smooth as before.

The other advantages of S136 steel are as follows

1.No special protection is required when the mold is operated or stored in a humid environment.

2.Lower production costs

As the cooling channel of the mold is not affected by corrosion (unlike ordinary mold steel), the heat conduction characteristics and cooling efficiency remain stable during the life of the mold, ensuring a permanent forming time for the mold. STAVAX ESR (S-136) is recommended for all molds. Due to its special properties, it is more suitable for the needs of special environments.

3Anti-corrosion and rust. For molds that use corrosive PVC, acetate and other injection molding materials or must be operated and stored in a humid environment.

4Abrasion resistance The use of injection mold materials (including thermoset injection molds) that require high wear or require molds to have a longer working time, such as electronic parts, disposable table knives, utensils, etc.

5Production of optical products such as cameras, sunglasses, chemical instruments, and plastic products with high smooth surfaces.

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

1.2343 tool steel is in DIN standard, and in JIS it is SKD6, in AISI it is H11. Our OTAI Special steel is the professional 1.2343 tool steel suppliers, we also supply other different tool steel grades.

Here following we will introduce the main characteristics and applications as below.

About 1.2343 tool steel applications: Tool steel stamped. Small hammer dies, large hammer and press inserts during the hot deformation of structural steels and non-ferrous alloys under conditions of large-scale and mass production. Injection molds of aluminum, as well as zinc and magnesium alloys.

For the 1.2343 steel characteristics as following:

1) High heat resistance hot work die steel.

2) Excellent toughness and scalability in all directions.

3)High thermal fatigue resistance and wear resistance.

4)Nitriding.

5)Good polishing.

6)Good dimensional stability.

7)Good hardenability.

8)Better isotropy than conventional smelted steel.

9)Can also be used for cold work dies.

As the 1.2343 tool steel suppliers, Otai exports various tool steel and alloy 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.Otai is stable and reliable supplier for Fortune 500 companies at home and abroad, such as Thyssenkrupp, China North Industries Group Corporation Limited.

As the history in the steel industry, OTAI always is insisting to ensure we keep providing quality products and differentiated services to our customers. while at the same time, ensuring the well-being of our staff. Heard that this virus maybe affect the global economy heavily. So maybe in the coming months, it will be very difficult for all of us. But I do believe that it is only through working together as a team that we will overcome the setback. OTAI will be always with all of you as the best 1.2343 tool steel suppliers.

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

Imagine that if you stop after forging Cr12MoV steel, allow the austenite to recover and start to recrystallize, and then quench immediately, it can inhibit the growth of austenite grains, and also inhibit the re-aggregation and hornification of carbides.

Waste heat quenching-double refinement Forging Cr12MoV steel process

(1)

During the forging Cr12MoV steel process, there are two contradictory factors at play: on the one hand, the hammering effect of forging, which causes the carbide to be broken and broken, and the austenite is seriously deformed; on the other hand, the Forging Cr12MoV steel temperature,it is higher and the deformation,The subsequent austenite immediately recovered，and recrystallized in the gap between hammers, and then began to grow. The crushed carbides also re-gathered with the hammer gap and gradually horned. The effect of temperature is continuous, and the refinement of hammering is intermittent. If the forging ratio is not enough, the stopping forging temperature is too high, and the number of fires is too large, the grains will be coarsened, the carbides will be coarse and multi-angled, the fracture of the workpiece will be coarse-grained, and the corners will be brittle.

(2)

When the sintering is stopped and slowly cooled, the carbides will grow, the carbon in the austenite is precipitated continuously, and the carbides are gradually keratinized, or the carbide keratinization is mostly formed during the sintering and slow cooling. The higher the forging temperature, the slower the cooling rate after forging, and the more severe the coarsening and horning of austenite grains and carbides. The sharp corners of carbides ，they are the focus of stress concentration and the source of fracture，which for early brittle failure of tool and die. Changing the distribution and morphology of carbides，it can extend the service life of the tool and die.

(3)

Imagine that if you stop after forging Cr12MoV steel, allow the austenite to recover and start to recrystallize, and then quench immediately, it can inhibit the growth of austenite grains, and also inhibit the re-aggregation and hornification of carbides. A relatively satisfactory carbide particle size and morphology can be obtained, which is the theoretical basis of the forging waste heat quenching process. If combined with appropriate firing times and forging ratios, we can explore the best forging waste heat quenching process scheme to obtain the effect of double refinement of carbides and austenite grains.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

42crmo4 plate steel pre-hard nice thickness is under loading!

Today is another day! The rainbow comes after the rainy day. Although times seem a little hard amid the pandemic, it will pass just like a miss. As a member of Otai company, I want to share the update product news with you. That is, We have 42crmo4 plate steel pre-hard, the nice thickness is under loading! If anyone likes it, please let me know.

I want to talk about something interesting to you. the culture between china and the other china is really different. Just like china, most countries imitate measures we took to prevent the spread of the coronavirus. The prominent way is quarantine. What’s the difference when everyone is quarantined. In China, we are stuck at home, cook delicious food, watch TV, or play the TikTok. This is our daily life during the past two months. We even not dare to go out walking. We have to enjoy the quiet time at home until the government resumes the factory. We finally can enjoy a rich life.

However, the foreign country is totally different. They sing songs and dance at home, chatting with friends online or do exercise at home. Compared with the Chinese, they are outgoing. They think they should live as they want even during the quarantine time.

When we back to work, we find we are fatter than before. More interesting, everyone prepares the supper personally. We find our cooking skills are really improved a lot.maybe this is another thing we shall be thanked for during the hard times.

Otai company keeps the daily stocks for our customer, 42crmo4 plate steel pre-hard, the nice thickness is under loading! To serve the customers,we are fighting.

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

Cr12MoV steel Six-sided forging

Cr12MoV steel Six-sided forging

Cr12MoV steel hexahedral forging,it refers to the combined process of three-way upsetting and drawing.

Each time,A certain forging ratio is required,it make the eutectic carbide gradually,it become irregular and uniformly distributed,or nearly uniformly distributed. Unidirectional drawing is a commonly used method in actual production. The carbides distributed in the network are forged into bands,and the carbides are also broken. This forging process is still feasible for long-axis workpieces, but it is also suitable for molds. In terms of anisotropy,when pulling in one direction,there is obvious anisotropy.Although large die blanks are sometimes forged reasonably,their central structure is still difficult to be significantly improved.

Thallium carbides are stacked in a network and carbides are stacked in a band

Rhenium carbides are randomly and uniformly distributed.The number of upsetting forgings shall be determined according to the specific circumstances, but shall not be less than three forgings and three forgings.

(1) Technical requirements for die forgings

Generally small precision molds with high toughness requirements require carbide unevenness levels of less than or equal to 2, general molds or large molds can be appropriately relaxed.

(2) The level of carbide unevenness in raw materials Cr12Mov.

If the level of carbide unevenness in the supplied steel is high, for example, the electroslag steel ingots that have not been bloom-rolled, the dendritic carbides are very developed and the level of carbide unevenness is high Therefore, it is necessary to repeatedly forge and forge. Even so, it is still difficult to completely change the carbide distribution by forging. For another example, although the large-sized steel used in large molds is rolled, most of the carbides in the center of the steel still remain in a networked distribution. For such large mold blanks, a reasonable six-sided forging must be carried out. Even so, the level of carbide unevenness is often difficult to be lower than 3 levels.

The carbides still have a more or less directional distribution even after a good six-sided forging, so it is necessary to consider that the long side of the mold should be consistent with the rolling direction in order to make full use of its higher longitudinal direction. The outer edge part of the metal with relatively uniform properties and carbide distribution, and the part with the largest hole type and wear, should avoid the center part with the worst quality of the blank as much as possible, because the carbide at this place is the easiest to homogenize.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

Cr12MoV forging cannot be simply understood as blank forming.For steel and prolong the service life of the mold,forging is an important key to improve the inherent quality, Through reasonable forging,not only the density of the forging slab can be increased,the pores,looseness, shrinkage, and microcracks in the ingot ,or profile can be welded together, but the eutectic carbide can be crushed and refined, and the coarse dendrites,The eutectic carbides are scattered and broken,to improve the uniformity of carbide distribution,and refine the particle size of carbides.

Forging characteristics of Cr12MoV steel material

(1) Poor plasticity of steel Cr12MoV steel belongs to bainite steel.

The steel has a large amount of carbides, is hard and brittle, and has poor plasticity, especially when the eutectic carbide dendrites are very developed and the carbide bulk is very coarse.The easiest to crack.

(2) Large deformation resistance of steel.

Due to the high content of carbon and alloy elements in steel, the austenite recrystallization temperature increases, and its deformation resistance is 2 to 3 times higher than that of carbon tool steel.

(3) Poor thermal conductivity of steel

Due to the poor thermal conductivity of steel, it must be preheated in stages during heating,otherwise cracks will occur during heating.

(4)Easily over-burned during heating.

In unforged Cr12MoV steels, eutectic carbides are mostly clustered and reticulated. The melting point is the lowest and it is easy to melt. Therefore, the forging heating temperature should not be too high. On the other hand, due to the large deformation resistance of the steel, the forging heating temperature cannot be too low, so the forging temperature range is relatively narrow.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

In order to reduce or eliminate the adverse effects of Cr12Mo1V1 ,which of the uneven distribution of eutectic carbides on it,which it on the mechanical properties and deformation of the mold, it is necessary to forge the raw materials. If it is not forged, it is necessary to seek to improve the unevenness of carbide distribution from heat treatment. The adverse effects are extremely difficult.

Forging process of Cr12Mo1V1 steel

The reasonable forging process of Cr12Mo1V1 steel is as follws:

Preheating temperature: 750 ～ 850 ℃;

Heating temperature: 1080 ～ 1120 ℃;

Initial forging temperature: 1050 ～ 1100 ℃;

Finishing temperature: 850 ～ 900 ℃;

Cooling method: slow cooling (pit or sand cooling)

Cr12Mo1V1 steel has poor thermal conductivity

During the forging process, the heating and cooling speed should not be too fast, so as to avoid excessive temperature difference and cracking on the cross section of the mold blank. It is necessary to strictly control the forging temperature. If the stopping forging temperature is too high, which causes the grains to grow and coarsen, and carbide aggregation occurs, the mechanical properties of the steel may be reduced; and if the stopping forging temperature is too low, the plasticity of the steel is poor. Increased stress easily leads to cracking and scrapping of the billet.

In order to improve the uneven distribution of carbides in Cr12Mo1V1 steel.

In the forging processing,it is necessary to pay attention to the correct method. Multi-direction and multiple times of upsetting and drawing are generally used, such as three forging three or three or more forging methods, and two light, one heavy, two uniform forging experience. Two light and one heavy refers to tapping at the beginning of forging (in the range above 1050 ℃), the hammering force should be small, and hitting between the intermediate temperature range (950 ~ 1050 ℃) to ensure that the carbides are broken, and it will be lighter again below 950 ℃ Hit to prevent cracking. The so-called bi-uniform means uniform deformation and uniform temperature.

Molds with different performance

The level of carbide distribution unevenness allowed after forging,it may also be different. Generally, molds with high requirements,which for impact toughness and deformation should be controlled below 3 levels. If hardness, strength, wear resistance, impact toughness and deformation are all required, the level of unevenness of carbide distribution should be strictly increased. Control is generally required to be below 2 levels,and it is best to control the cold extrusion die at 1 to 1.5 levels.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

P20 steel supplier Otai special steel company

Today is a nice day for us because we are busy pack the gift-mask for our dear customer. Although the country and culture are different,the care and love are boundless. We believe the bright future will finally come. As a P20 steel supplier, we hope everyone is safe and keep health.

P20 steel differs from area to area in different countries. Europeans generally use the DIN spec-DIN EN ISO 4957 standard materials (1.2311 and 1.2312), while in Japan steel industry standard, PX5 is the new standard P20. And the Americas Countries, Grade steel P20 is the most and widely used steel grade material. In China, 3CrM2Mo is the P20 steel grade equivalent, which is in the standard GB/T 1299 tool steel specification.

P20 supplier Otai contributes to providing the perfect steel for the customer. It is Main be applied to in zinc, aluminum, magnesium, and its alloy die-casting mold; Hot-pressing mold, all kinds of a hot forging die; Metal extrusion dies, die set.

As a P20 supplier, we can supply the round bar, flat bar, plate 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. The tolerance will be strictly applied according to clients’ requirements.

P20 steel supplier Otai’s Regular size and Tolerance

Steel round bar: Diameter Ø300mm –500mm

The hardness is uniform, quality is assured, the delivery time is desirable. Any questions,please don’t hesitate to reach out to me.

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

OTAI supply the grade 4140 widely. Recently we sold a lot of grade 4140 steel plates which is for fulfilling the mould parts. This mould is used on the facemask-producing machine widely.

During the end of Jan to the early of March, China was going through the dark and difficult time because of the virus. There was a lot of fear here. Most of people in Hubei have become infected, and they were isolated from their families and their loved ones. And they have to be alone in the wards.They do not even have a chance to say goodbye when they passed away. Someone chased and run after the ambulance when their loved ones died and was delivered to the cremation. This virus is indeed terrible. It affected the people in different age, no matter elder or younger, healthy and ill.

It seems that we pressed the stop button in our life. All the streets were empty, everybody stayed at home . The virus was rampaging. The numbers were increasing in every day. The rumors were spreading, and the fear is growing. The whole country lost its original vitality and prosperity. But people life are the most important, people are at the heart of our world. So at this time, life means everything. Staying yourself at home and staying safely is the greatest contribution we could do for our own country.

Usually, in the difficult time, someone became the hero, and someone was with the shameful behavior. Some leaders did nothing at that moment, but some normal ones with the very sincere spirit on their devotion. Someone sold the mask in a very high price at this special difficult time. Someone gave the facemask for free. People always say that life is a mirror. Here I would like to say the virus is also a mirror.

At this special moment, we should work as a strong team to overcome the virus and help each other. A friend in need is a friend indeed. These days, OTAI is a supplier who supplies the grade 4140 widely. We for supporting to the customers located in the serious area and country, we do our best to send some facemask to them. Sincerely hope them, their loved-ones, friends and colleagues remain safe and healthy. Lets’s go through the difficult time together, expect our more working together no matter on the grade 4140 but other more steel grades.

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com