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Many friends asked for the steel code lately,then I collect some as below.

American standard AISI Steel Code:

P1 – P19: LowCarbon Steel

P20-p39: Low Carbon, High Alloy Steel(plastic die Steel)

2 xx, xx, xx 4, 6 xx: Stainless Steel (Stainless Steel)

H1-h19: Chromium base (Chromium base – hot working steel)

Wx: Water Hardening Steel

Sx: Shock Resisting Steel

Ox: OilHardening Steel (Steel)

Ax: AirHardening Steel

Dx: High Carbon, High Chromium Steel

Mx: Molybdenum base (H.S.S.- high speed steel)

German standard DIN Steel Code:

Low carbon, high alloy (p20-plastic die steel)

Lowcarbon, high alloy (p20-plastic die steel)

Lowcarbon, high alloy, free Machine (p20-free cutting)

StainlessSteel (420 – acid-fast steel)

1.2316: Highperformance stainless Steel (420 – high acid Steel)

1.2343: Chromiumbase (Chromiumbase -H11 – hot working steel)

1.2344: Chromiumbase (chromium-based -H13 – hot working steel)

Lowalloy steel (o1-oil steel)

1.2379: Highcarbon, high chromium steel (D2 — chromium steel)

Japanese standard JIS Steel Code:

SxxC: Plain Carbon steel(yellow card-s55c)

SUSxx: Stainless Steel, acid Steel – 420)

SCrx: Chromium Steel

SCMx: Chromium Molybdenum Steel (P20)

SKx: Carbon Tool Steel

SKSx: Low Alloy Steel (oil steel-o1)

SKD11: MediumHigh Alloy Steel(chromium-d2)

SKD6: Medium High Alloy Steel(Medium High Alloy Steel -H11)

SKD61: Medium High Alloy Steel(Medium High Alloy Steel –H13)

SKHxx: High Speed Steel (hs-m 2)

SUMx: Free Cutting Steel

SUJx: Bearing Steel

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

According to the life of the mold into five grades, the requirements of mold steel:

Generally, the mold is divided into five grades according to the length of service life.

Level NO1:more than a million times,

level NO2：is 500,000 to 1 million times,

level NO3:is 300,000 to 500,000 times,

level NO4: is 100,000 to 300,000 times, and level 5 is less than 100,000 times.

The first and second grade molds are required to use heat treatment

Hardness in HRC50 or so of steel, otherwise it is easy to wear, the injection of the product is prone to out of tolerance, so the selected steel should have good heat treatment performance, and in the state of high hardness has good cutting performance, of course, there are other considerations.

Usually choose Sweden’s die steel

(1)

8407, S136, the United States of mold steel 420, H13, Europe’s 2316, 2344, 083, or Japan’s SKD61, DC53 (the original metal mold material, special circumstances use).

(2)

Strong corrosive plastic generally choose S136, 2316, 420 and other steel, weak corrosive in addition to mold steel S136, 1.2316, 420, and JIS SKD61, NAK80, PAK90.

Product appearance requirements

(1)

It also have a great impact on the choice of mold materials, transparent parts and surface requirements mirror products, materials available are S136, 2316, NAK80, PAK90, 420, the transparency of the mold should be selected S136, followed by 420.

(2)

There are many pre-hard materials for the three-stage mold,mold steel grades are S136H, 2316H, 083H, and the hardness is HB270-340.

Mold steel

P20, OT718, 738, OT618, 2311, 2312, 2711 are used for grade 4 and grade 5 molds. For the molds with extremely low requirements, S50C and S45C steel may be used, which is to directly make a cavity on the mould blank.

If you want to know more or any suggestion,please conract me,let’s discuss more.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

As you know, Otai sells different kinds of round steels. however, do you know about it?

Round steels are a long bar of solid steel with a circular section. The specification is expressed in diameter in mm (mm)

Classification of round  steels

Round steel is divided into hot rolling, forging, and cold drawing. The specification of hot rolled round steel is 5.5-250mm. Among them: 5.5-25mm small round steel is mostly supplied in bundles of straight bars and is commonly used for reinforcing bars, bolts, and various mechanical parts; round steel with diameter  More than 25 mm, mainly used for making machine parts, seamless steel tube billet.

Commonly used material of round steel

Q195, Q235, 10#, 20#, 35#, 45#, Q215, Q235, Q345, 12Cr1Mov, 15CrMo, 304, 316, 20Cr, 40Cr, 20CrMo, 35CrMo, 42CrMo, 40CrNiMo, GCr15, 65Mn, 50Mn, 50Cr, 3Cr2W8V, 20CrMnTi, 5CrMnMo, etc.

standard of round steels

Standard: (gb699-1988, gb700-1988, gb3077-1988, gb702-1986, QJ/ hg02.17-1991)

The difference between round steel and other rebars:

1 appearance is not the same, round steel appearance light circle, no grain without rib, other rebar surface appearance has cut grain or have rib, so as to cause round steel and the concrete bonding force is small, and another rebar and the concrete bonding force are large.

2 composition is not the same, round steel (grade steel) is common low carbon steel, other steel reinforcement for alloy steel. Three different intensity, low intensity of round steel and other steel with high intensity, the diameter of the same size of round steel compared with other steel bars, round steels can withstand strength than other bar is small, but the plastic is better than other steel round steels, the round steels before is pulled with large deformation, and other steel before being pulled deformation is much smaller.

Theoretical weight

Theory of round steels weight calculation formula: outer diameter *diameter *0.00617 kg/m=weight of per meter

As for carbon steel, The carbon content is less than 1.35%, except for iron, carbon, and impurities such as silicon, manganese, phosphorus, and sulfur within the limit, steel without other alloying elements. The performance of carbon steel mainly depends on the carbon content. With the increase of carbon content, the strength and hardness of steel increase, and the plasticity, toughness, and weldability decrease. Compared with other steels, carbon steel is the earliest to be used, with low cost, wide performance range, and the largest consumption.

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

There are three main ways to change the properties of die steel steel:Alloy composition、Smelting process、Heat treatment

There are three main ways to change the properties of die steel steel:

1、Alloy composition

Carbon: C

Increase the hardness of quenched tissue;

Forming carbide to improve wear resistance;

Reduced toughness;

Reduce weldability

Cr: Cr

Increase the hardness of steel, forming hard and stable chromium carbide, thus improving wear resistance;

Can improve the hardenability of steel;

When Cr content exceeds 12%, it is resistant to corrosion and provides good optical rotation

Mo, Mo

Mo is a strong carbide forming element to improve wear resistance.

Mo b b 0 0.5% can restrain the tempering brittleness caused by other alloy elements.

Provide red hardness, thermal intensity;

Increase the hardenability, temper stability

V: V

High hardness carbides can be formed to improve wear resistance.

Fine steel grain, reduce the sensitivity of overheating

Improve the strength, toughness and tempering stability of steel

Nickel: Ni

Ni can increase the hardenability of die steel;

Ni refines grains

Sulfur (S)

Often exists in steel in the form of MnS, breaks the continuity of matrix, deteriorates the material’s toughness, corrosion resistance, optical rotation, discharge processing, etch, can improve the cutting ability of the material.

2、Smelting process

Common steelmaking process

(1) electroslag remelting (ESR)

The thick billet is placed in the electroslag furnace, and a strong current is put into the furnace to produce a very high temperature, so that the thick billet is melted into molten steel, and the molten steel flows through the electroslag, and the impurities are filtered and absorbed by the electroslag, so as to achieve the purification effect.The overall remelting is fast, but some very fine impurities are not removed.

(2) vacuum arc remelting (VAR)

In a vacuum furnace, a strong electric current is applied to the steel shell. The bottom of the steel shell begins to melt, and the impurities are vaporized into gas and pumped away, thus improving the purity of the steel.It is characterized by thorough removal of impurities but slow overall remelting.

3、Heat treatment

The heat treatment of die steel refers to the process of heating and then cooling, by controlling the heating temperature, holding time and cooling speed of steel to change the properties of steel, in order to meet the requirements of processing or use.The main heat treatment processes are: annealing, quenching, tempering.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

In the production process of iron and steel plate products, when the blank is pressed, the surface wrinkle, the surface is not flat phenomenon, is a common punching defect.

This not only leads to the waste of raw materials, sometimes also increases the subsequent scrap, such as automotive stamping parts wrinkle, will directly lead to the welding process after welding poor quality or even welding joint cracking.So how does the wrinkling happen?

When the steel plate is pressed and deformed, it is subjected to the tensile stress in the plane drawing direction and the compressive stress in the plate thickness direction.Under certain pressure, the thinner the plate, the easier to wrinkle.

At the same time, during the processing, the maximum tangential compressive stress appears on the edge of the flange, that is, the wrinkle on the outer edge is the most obvious.

Product wrinkling mainly from three aspects to find the reasons:

1、Parts design

Is the product model reasonably taking into account the molding problem, is the press bar set too small?Does the place that crinkle easily need to add to absorb crinkle rib?

Solution: increase the bar or change the layout of the bar.Add wrinkle absorbent to scrap section.

2、Process design

A) the pressure surface is loose and tight

Solution: repair the grinding press surface.

B) unreasonable shape of filling surface

Solution: modify the shape of the feed surface to avoid the uneven material flow caused by its shape immobility.

C) reasons for blanks.The blank is too small or the blank is not positioned properly in the mold

Solution: increase the blank size.Improve the blank positioning on the mold so that the mold can accurately press the steel plate.

D) too little pressure

Solution: increase the mandrel pressure.

E) the gap between upper and lower modules is too large

Solution: adjust the gap.

F) the fillet radius of the die mouth is too large, which makes the punch unable to press the material

Solution: reduce the radius of the fillet.

G) too much grease

Solution: apply oil according to the requirements of the operation regulations to ensure the correct position and amount of oil applied

3、Materials

The yield strength of the material is not up to the standard and the material is too soft.

Solution: to ensure the product performance, the use of better formability of materials.

For different cases, specific problems need to be analyzed, but in the final analysis, it is still inseparable from the above principles.With such a train of thought, if encounter corresponding problem again, you do not need to worry about this little wrinkle again!

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com

SCM440 Steel Plate Mold for Mask Machine direct use . The mold have machined , heat treated , for mask manufacture .

quivalent material

• ♦JAPAN♦ : JIS SCM440 alloy steel

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

• ♦CHINA♦ :  GB 42CrMo steel

• ♦BRITISH♦ : BS 708M40

• American : AISI 4140

SCM440 Steel Plate 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 .

SCM440  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 .

SCM440 Steel Plate 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 .

SCM440 Alloy steel material stockholders and suppliers from China-OTAI SPECIAL STEEL . we have more 16 years experience in SCM440 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 .

SCM440 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

seamless steel 440 is a kind of economic section steel. it is widely used in the manufacture of structural parts. Otai company provides it for our clients.

Seamless steel tube is a round, square, rectangular steel with a hollow section and no joints around it. A seamless steel tube is made of the ingot or solid tube blank through the perforation into a capillary tube, and then by hot rolling, cold rolling, or cold drawing. Otai company provides Seamless steel 440 for our clients.

Seamless steel pipe has a hollow section, a large number of pipe used for conveying fluid, steel pipe and round steel and other solid steel, in the same bending and torsional strength, weight is lighter, is an economic section of steel, widely used in the manufacture of structural parts and mechanical parts, such as oil drilling steel scaffolding.

Use and classification of seamless steel tube

Application: A seamless steel tube is a kind of economic section steel, which has a very important position in the national economy. It is widely used in petroleum, chemical industry, boiler, power station, ship, machinery manufacturing, automobile, aviation, aerospace, energy, geology, construction, and military industry.

Classification:

(1)According to the section shape: circular section tube, shaped section tube

(2)According to the material: carbon steel pipe, alloy steel pipe, stainless steel pipe, composite pipe

(3)According to the connection: threaded connection pipe, welding pipe

(4) according to the production mode: hot rolling (extrusion, top, expansion) tube, cold rolling (drawing) tube

(5) according to the use of the following: boiler pipe, oil well pipe, pipeline pipe, structure pipe, fertilizer pipe

Seamless steel tube production process

(1) main production process of hot rolled seamless steel pipe (main inspection process) :

Preparation and inspection of tube billet → tube billet heating → perforation → rolling pipe → reheating of raw pipe → fixing (reducing) diameter → heat treatment → straightening of finished pipe → finishing → inspection (nondestructive, physical and chemical, table inspection) → storage

(2) cold rolling (drawing) seamless steel pipe main production process

Blank preparation → pickling lubrication → cold rolling (drawing) → heat treatment → straightening → finishing → inspection

If you want to know more about stainless steel 440, welcome to contact me.

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

34CrNiMo6 Intorcution –Properties/chemical/application/heat treatment

34CrNiMo6 steel Intorcution –Properties/chemical/application/heat treatment

34CrNiMo6 is equal to 1.6582 .

The chemical of the grade for 34CrNiMo6 and 1.6582 as the below sheet :

The application of 34CrNiMo6:

34CrNiMo6 is a typical difficult-to-machine material, widely used in the manufacture of important parts such as camshafts and connecting rods of engines.

The 34CrNiMo6 alloy is high-strength. Because of its excellent comprehensive mechanical properties, it is widely used in the manufacture of engine camshafts and connecting rods and other important parts.

The stock for the specification as the below :

Mechanical properties of 34CrNiMo6 as the below mention :

After 34CrNiMo6 material is quenched and tempered, the hardness is 36-40 HRC, the tensile strength σb is 1 100 MPa, the elongation δ is 12%, and the impact toughness value ακ is 8 kg / cm2.

Heat treatment:

The tempering process of 34CrNiMo6 is 850 oil quenching and 580 degree tempering.

Quenched and Tempered (Q+T) of 34CrNiMo6 Steel

• Heat 34CrNiMo6 round steel slowly to the temperature of 850°C;
• Soak at this hardening temperature quench in oil;
• Temper as soon as 34CrNiMo6 steels reach room temperature.
• Heat uniformly to the suitable temperature;
• Withdraw from the furnace and cool in the air.
• The usual tempering temperature is 600°C which depending on the actual requirements.

WhatsApp: +86-769-23190193

Tel: +86-769-23190193

Fax: +86-769-88705839

Email: Jack@otaisteel.com

On one hand, the pandemic causes badly damage to the global economy, on the other hand, it takes a new chance for the special steel industry.

The pandemic takes the new chance for the special steel industry

On one hand, the pandemic causes badly damage to the global economy.on the other hand, it takes a new chance for the special steel industry. As a member of the Otai special steel company, we have faith we can finally fight the pandemic. We will take advantage of the chance to provide better steel for our customers. In 2020, we will insist on providing high-quality 4140 steel,p20 steel, and 440 Steel.

High-quality development currently requires the industrial chain to move from the low end to the high end. Because of this, the epidemic provides the special steel industry with an industry consolidation to achieve the survival of the fittest opportunity.

Due to the epidemic situation, the market demand for special steel products is insufficient. However, the production of special steel enterprises is not reduced during the epidemic period. The combination of the two factors leads to the sudden rise of inventory pressure. It also stimulates the prominent contradiction between market supply and demand. At the same time, the global epidemic makes it more difficult to export. Enterprises suffer multiple impacts. In general, the outbreak has a huge impact on the special steel industry, special steel demand, especially high-end special steel demand decline.

The future development trend of special steel

The future development trend of the special steel pandemic, we provide the different sizes of mask mold for the mask manufacture. If you want to know more about it, please contact me. must be that the demand for steel quality, performance, and variety is greater than the demand for steel quantity. In other words, it is the quality, performance, and variety of special steel that will lead and guide the future market.

To satisfy the requirement of the customer’s different sizes, we bought the new cutting machine. Otai devotes to improve the high-quality after sell service and better special steel for our customers .during the pandemic, we provide the different sizes of mask mold for the mask manufacture. If you want to know more about it, please contact me.

Mr Jack Tan

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: jack@otaisteel.com

The so-called non-quenched steel is a new kind of steel made by adding trace alloy elements such as V, Nb and Ti into medium carbon steel.In most cases the total amount of microalloys added is generally not more than 0.25% (0.25%).

Non-quenched steel’s advantages

The world’s first non-quenched steel was introduced in 1970 by GERLACH, a German company, which produced crankshafts using CK45 steel instead of the quenched steel they had just developed.Because the use of non-tempered steel production forgings can save the tempering treatment (quenching + high temperature tempering) in the process of two heating and energy consumption, so it has the advantages of energy saving and environmental protection, known as green steel.

Cost of heat treatment

In 1973, the Middle East war broke out, the high oil price forced people.they pay more attention to energy conservation and consumption reduction. Under this background, the development and utilization of non-quenched steel.it’s set off a climax in the west.with each country successively introducing its own non-quenched steel.By 1984, from non-quenched steel,60% of Japan’s crankshafts, 50% of its connecting rods were forged.The germans say, using 49MnVS3 non-quenched steel.It can instead of quenched steel.Aichi.A Japanese company, says that using non-quenched steel can cut costs by 18%.

Strengthening mechanism

Forgings, whether made of tempered steel or non-tempered steel.It cannot be used without strengthening treatment after forging.Different steels have different strengthening mechanisms.The strengthening mechanism of quenched steel is: First through quenching.The steel is made into martensite, and then the martensite is made into tempered sostenite by tempering treatment.

Tempered sostenite is a stable structure with good comprehensive mechanical properties.

Rather than the reinforcement mechanism of quenched and tempered steel. first, in the heating process,non quenched and tempered steel V, Nb, Ti.Alloy elements in the form of alloy carbon compounds, before forging fully dissolve in the austenite. and then,in the process of cooling after forging.The carbon and nitrogen compounds from austenitic alloy precipitation.Forming numerous small, scattered alloy carbon compounds.At the same time, the fine ferrite steel can improve the strength and hardness of steel.

Ms Sharon Wan

Mobile/WhatsApp: 0086-13580960968

Tel: 0086-769-23190193

Fax: 0086-769-88705839

Email: Sharon@otaisteel.com