Alloy Steel

What is alloy steel?

That is the first thing we think about it when we know nothing about it. And it is a type of steel that was made by adding one or several alloy elements in the production. It was made at the basics of carbon steel, which is good for its properties. And about its properties, it has high mechanical propeties, hardenability, tempering stability and more. And someone has special properties, such as the acid-resistant, heat resists and etc.

What is the effect of alloy element for alloy steel

Raise The Hardenability

All alloy elements will increase the stability of overcooling austenite after they all dissolve in austenite, except the cobalt. And decrease the critical cooling speed of steel, increase the hardenability of steel. The alloy elements that people always use to make the hardenability get better are molybdenum, manganese, chromium, Ni, B and more.

Intensify Delta Ferrite

Most of the alloy elements can be dissolved in delta ferrite to become alloy delta ferrite, except the plumbum. The difference of atomic radius of alloy elements and iron will cause the delta ferrite to get change. That will increase the strength, hardness and decrease plasticity and toughness.

Alloy Steel Types

According to the applications, there are three types for alloy steel. They are alloy structural steel, alloy tool steel and special alloy steel. And you maybe heard about low alloy steel, medium alloy steel and high alloy steel. They were classified by alloy content. If the alloy content is less than 5%, it is low alloy steel. The alloy content at the range of 5% to 10%, it is medium alloy steel. Finally, the alloy content of high alloy steel is bigger than 10%. And at the steel market, most of them are low alloy steel and high alloy steel.

Alloy Tool Steel

There are three types of alloy tool steel. They are alloy cutlery steel, alloy mold steel and alloy gauge steel. Alloy cutlery steel is a good material for making turning tool, bit, milling cutter and all kinds of metal cutting tools. It must have high hardness, hot hardness and wear-resistance and great toughness and strength.

4140 Steel is good material for blade?

The history of the blade is fantastic. It is the tools for human life, used to do the housework, even it is the best weapon for soldiers in the war so many years ago. So many years went by, it becomes more and more important in daily life. In the industry, the processing and production need it to finish the job to make the products. And it has so many branches due to the different applications.

The steel is good material for the blade. But different steel types will cause different impacts for blades. Let's check out what 4140 steel really is then think about its effect on blades.

What is 4140 steel?

AISI 4140 steel is one of the alloy steel. It is very popular in the industry as one of alloy steel. It has high strength, toughness and hardenability. The properties of 4140 steel and 4340 steel are similar, but the carbon element of 4140 steel is higher. Because of that, the properties of welding for 4130 steel is better than 4140 steel.  This type of alloy steel, must do the processing of heat treatment to explode its mechanical property. Do not use it directly. If not, the steel will crack. In China, people usually call it as 42Crmo steel. The properties of them are similar, there is a little difference in the use.

What is best choice for blade?

Due to the properties and chemical composition of 4140 steel, it is not good for the blade. Its requirements for steel properties are really strict. 4140 steel hardness, toughness, wear-resistance are not catching the requirement. The high-speed steel is more good for it. Such as the M2 steel.

Steel Supply for China

Steel Supply

China is a big part of the steel supply in the world. For that, China put so many alloy steel, carbon steel, mold steel, high-speed steel and etc to the world for each country. It is a big power for industry development in the world. 

Steel supply policy

Steel supply to other countries has a good policy in China. The main part is that suppress low value-added steel exports and encourage high value-added steel exports. And the example is that billet, carbon steel, stainless steel, alloy steel and etc. That is closely-related with our local economic development and export environment condition.

First of all, China must take the pressure more and more as the day going into this world economy development condition. According to public information, there were as many as 37 times anti-dumping and countervailing cases against steel products in China in 2015. In 2016, this figure was 43 times. And another thing is that local develop structure is unbalanced. In order to bring the production gets better, must keep down the lower production and take the effort to make high-value products. So in recent years, the government raise the export tax for this part slowly to make it down. Finally, the environment production is the most important purpose. Iron and steel smelting is a high-pollution and high-emissions industry. By raising the export tariffs on ordinary steel, it is conducive to reducing the demand and output of ordinary steel.

Chinese steel export situation

China is the main countries for the world at the part of steel production. The steel production is 1.138 billion tons, it is almost 70% for the world. Steel export volume is positively correlated with the steel price. The lower the steel price, the more exports. In 2015, steel prices fell to the lowest level, while the export volume reached its peak. In 2016, with the implementation of the national supply-side reform, steel prices stopped falling and steel exports fell.

Main type for Chinese steel supply for the world

According to the data, the most popular types for our country export is the bar, rod, tube and etc. Mainly based on plates and bars, the exports of plates and bars in 2016 were 48.03 million tons and 41.26 million tons, respectively, accounting for 44% and 38% respectively.

The main countries of steel export for China

Southeast Asia is the main part of that. According to the export amount, South Korea is the biggest one. In 2016, it imports steel from China almost 14.33 million tons. China's top 10 countries in terms of steel exports, in descending order: South Korea, Vietnam, the Philippines, Thailand, Indonesia, Malaysia, India, Saudi Arabia, Singapore and Pakistan.

As the country with the second-largest export volume of steel in China, Vietnam has been at a high level in recent years due to its infrastructure and urban construction demand, and the demand for steel is huge. The growth rate of China's exports of Vietnamese steel is obvious, rising from 7% in 2014 to 11% in 2016. At the same time, Vietnam also belongs to China's trade scope with the “Belt and Road” countries. China's steel traders are currently actively expanding customers in Southeast Asia, the Middle East and Africa.

What is the best material for making blade tools

Blade tools are mostly used in the industry of machine production. Most of them are suitable for machines. They are used to cutting metal material frequently to improve production efficiency. They are used in different areas, such as the geological prospecting, dig the well, etc. So different demand cause different blade tools with different properties, technology, material, etc. And the material paly a inportant role for the blade tools. As below, I will show you guys what material are good for it and its impact. Then you can choose the right one for you according to your condition.

154CM steel

154CM is a 440C high molybdenum modified steel grade. The addition of 440C to the wear resistance of the material (especially the anti-rolling performance) improves the corrosion resistance of the material and has better machinability. The chromium content is 15% and the molybdenum content is 4%; so the name is 154CM. R.W.Loverless, one of the masters of modern hand-made knives, took the lead for it.

It has excellent processability, corrosion resistance, blade resistance and toughness. However, the price is higher, so it is only used in hand-made tools. The carbon content is about 1.05%. And after heat treatment, its hardness can up to HRc60~61 .
It is only a medium level in the four indicators of grinding, retention, rust and toughness. For example, comparing VG10, as a traditional steel of the same grade, VG10 has better grinding, hardness and sharpness. Although the toughness is easy to collapse, but the characteristics are clear.

ZDP-189 steel

ZDP-189 steel is a powder-based new steel developed by Hitachi Metals in Japan in 1996. It is a super-hard alloy steel with excellent processing properties. Its carbon content is 3% and a chromium content of up to 20%. After heat treatment, the high hardness can reach HRc67, and the processability is excellent. The metal structure particles are more uniform and finer than ATS-34 and 440-C. The resulting tool has a high hardness, excellent retention and a slightly higher grinding difficulty.

Representative companies currently using them for the production of tools are Spyderco and ROCKSTEAD. Among them, Spyderco produces more popular and cost-effective folding knives. However, ROCKSTEAD is more inclined to high-priced tools at the boutique collection level. Spyderco officially said that its hardness after heat treatment can be 62-64HRC, while ROCKSTEAD is 66-67HRC.

It has an extremely high hardness of 67HRC. It also has a high degree of retention, sharpness and easy to polish. In some high-end sushi knives in Japan, ZDP-189 is often used. Although it is easy to rust and has a low toughness, it is a high-end steel with no doubt on the folding knife.

M2 steel

M2 steel is one of the high speed steel (HSS). It has great wearing resistance. And Its toughness is not better than high level steel, but it is better than stailess steel. The wearing resistance is the same situation.

52100 steel

S7 steel is a alloy steel with chromium and molybdenum. It is a good choice for the machine of hot work mold steel cutting and etc.

About 4340 Steel

4340 steel is one of the most widely used materials in the industry. It belongs to alloy steel, due to it has alloy element in it. Adding alloy element to change the properties of it to make it satisfy the needs of industry requirement.

4340 Steel Properties

Because of the certain alloy elements be added, it has high strength and toughness. And has great hardenability and temper brittleness. But the weldability is bad. It needs a high temperature to preheating before welding. And after welding, must eliminate stress, could be used after quenching and tempering.

4340 Steel Application

It is a good material for the important fittings with high strength and good plasticity. And it could be used to manufacture important parts with special functional requirements after nitriding treatment. Such as shafts, gears, fasteners and etc.

And used as important tempering fittings which requiring good toughness, high strength with big size. For example:
heavy machinery high-load shafts
The dia is bigger than 250mm of turbine shafts
rotor shafts for helicopters
turbine shafts for turbine jet engines, blades, high load transmissions
crankshaft fasteners
It also can be as high strength steel to use after low-temperature tempering or after isothermal quenching.

4340 Steel Composition

C: 0.37%-0.44%
Si: 0.17%-0.37%
Mn: 0.50%-0.80%
Cr: 0.60%-0.90%
Mo: 0.15%-0.25%
W: 0.50%-0.80%
S: 0.030%
Ni: 1.25%-1.65%

The intensity of Tension: ≤980MPa
Yield Strength: ≤835MPa
Percentage Elongation: ≤12%
Reduction of Cross-sectional Area: ≤55%
Notched Bar Impact Strength: ≤98 J/cm²

4340 Steel Heat Treatment Processing

Hammered
Normalizing
Annealing
Rough Machining
Austenitizing
Finish Machining
Nitriding (optional)

STEEL CLASSIFICATION

There are so many types of steel and it can be classified by the application.
1. Structural Steel:
It was used to make metal structural parts in buildings, bridges, ships, boilers and etc. Such as carbon structural steel, low alloy steel, steel bar and etc,
It also is the material of structural parts on mechanical equipment. These steels are basically high-quality steel. The main parts are high-quality carbon structural steel, alloy structural steel, free cutting steel, spring steel, rolling bearing steel and etc.
2. Tool Steel:
Tool Steel always is made various tools, such as carbon tool steel, alloy tool steel, high-speed tool steel. It can be divided into cutting tool steel, mold steel and measuring steel by the application.
3. Special Steel:
It is with special properties, so people called it special steel. Such as stainless acid-resistant steel, heat-resistant steel, high-resistance alloy, wear-resistant steel, magnetic steel and etc.

Classified by chemical composition
1. Carbon steel:
Low carbon steel (C ≤ 0.25%), low strength, low hardness and soft. Often used in the manufacture of chains, rivets, bolts, shafts, etc. It includes most of the ordinary carbon structural steel and some high-quality carbon structural steel. Most of them are used for engineering structural parts without heat treatment, and some steel is used for carburizing and other heat treatment for mechanical parts requiring wear resistance.

Medium carbon steel (0.25% ≤ C ≤ 0.60%)has good thermal processing and cutting performance, poor welding performance. Plasticity and toughness are lower than low carbon steel. The hot rolled material and the cold drawn material may be directly used without heat treatment. The medium carbon steel after quenching and tempering has good comprehensive mechanical properties. The highest hardness that can be achieved is about HRC55 (HB538). So medium carbon steel is the most widely used in various applications at medium strength levels. Except being used as building materials, it is also used in the manufacture of various mechanical parts.

High carbon steel (C ≤ 0.60%) often been called tool steel, it can be hardened and tempered. Hammers, crowbars, etc. are made of steel which with a carbon content of 0.75%, and cutting tools such as drills, wiretapping reamers, and the like are made of steel having a carbon content of 0.90% to 100%.

2. Alloy steel:
Low alloy steel (total content of alloying elements <5%)
Medium alloy steel (total content of alloying elements >5~10%)
High alloy steel (total content of alloying elements >10%).

There are many types of steel and each one has its own application. It is very important to choose the right steel type according to the field that you in. We can find steel supply companies more easily right now behind the quick development of the network. Keep communicating with steel supplier or steel distributors and establish the type, grade, size, tolerance, delivery time and etc. By the way, you can ask the steel sample. Then you can fully understand the steel supply company of service, quality, price and more.

What Is The Chinese Steel Price Trend Right Now?

Chinese spot steel prices fell first and then rose, market demand was slowly recovering, and inventories continued to rise. The iron ore market was basically stable, and the high adjustment of imported ore prices was on the decline.

In the past week, Chinese spot steel prices have fallen first and then rose again. Specifically, at the beginning of the week, due to poor weather conditions in some areas, a considerable part of the downstream construction sites have not started normally, the demand recovery is relatively slow, and the inventory continues to rise, which has a restraining effect on steel prices. Near the weekend, the black futures market generally rebounded, and some mainstream steel mills also had a willingness to price, and market sentiment improved.

According to analysis, in the construction steel market, the average price of mainstream rebar varieties in major cities nationwide was 3,982 yuan per ton, down 27 yuan on a week-on-week basis. In the plate market, the average price of mainstream hot-rolled products in major cities nationwide was 3,823 yuan per ton, up 12 yuan on a week-on-week basis. From the latest inventory situation, the steel market inventory continued to rise as a whole, but the peak inventory level is expected to be lower than in previous years. The overall market mentality is still relatively optimistic.

                                       Chinese Songshun Steel Warehouse
The iron ore market is in a stable and weak state. According to the latest report, in the domestic mining market, the Chinese iron fines market is mostly stable, and some regions have slightly increased. Some steel mills purchase on demand, and the mining market has a strong wait-and-see attitude. The price of imported ore market was weak. As of the 22nd, the price of imported iron ore at 62% grade was 86.70 US dollars per ton, down by 1.1 US dollars on a week-on-week basis. At present, the imported ore market has not shown signs of replenishing the stock after the holiday. Although the imported mineral price rose to a stage high, the overall market confidence was insufficient, and the imported mineral price continued to rise at a high level.

Relevant institutions believe that the recent steel price has approached the winter storage cost line, coupled with the slight increase in the latest ex-factory prices of some steel mills, the willingness of merchants to sell at low prices is not high, and the cost support is strong. The production enthusiasm of steel mills in general and the space for production growth is limited. After the Lantern Festival, the downstream began to rework, and demand will continue to recover. In the short term, the steel market will be dominated by a slightly stronger operation.


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