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Hot Work Tool Steel VS Cold Work Tool Steel

Tool steel contains various amounts of tungsten, molybdenum, cobalt, and vanadium to increase the heat resistance and durability of the metal. This makes them ideal when used for cutting and drilling.

Tool steel is a type of carbon alloy steel that is well-matched for tool manufacturing, such as hand tools or machine dies. Its hardness, resistance to abrasion and ability to retain shape at increased temperatures are the key properties of this material. Tool steel is typically used in a heat treated condition which provides increased hardness.

Tool Steel is divided into these six groups: water-hardening, cold- work, shock-resisting, high-speed, hot-work, and special purpose.

Hot Work Tool Steel:
Our hot work tool steel is a uniquely processed group of steel used to shape and cut other materials at high temperature. Classified with the ‘H’ prefix, ‘H-group’ steels undergo intense processing to allow them to retain strength and hardness whilst being used in high-temperature conditions.

Cold Work Tool Steel:
Cold-work classes – Is a group of three tool steels: oil-hardening, air-hardening, and high carbon-chromium. The steels in the group have high hardenability and wear resistance, with average toughness. Typically they are in the production of larger parts or parts that have a minimum distortion requirement when being hardened.

Both Oil quenching and Air-hardening both reduce the distortion and higher stress caused by the quick water quenching. Because of this, they are less likely to crack.

D-grade of tool steel in the cold-work class can contain approximately 10% to 13% chromium. This type of tool steel does retain its hardness at increased temperature (425 °C / 797 °F max). The most typical applications for this type of tool steel is in forging dies, die-casting die blocks, and drawing dies.

Special steel is generally considered to be a steel that has a special chemical composition (alloying), is produced by a special process, has special organization and properties, and can meet special needs. Special steels have higher strength and toughness, physical properties, chemical properties, biocompatibility and process properties than ordinary steel.
In fact, in our normal life, the production of finished steel products that we are in contact with is also processed through various processes. So what are the special steel processing classifications?

1.Carbon steel

Carbon steel is also commonly referred to as carbon steel, and is an iron-carbon alloy having a carbon content wc of less than 2%. Carbon steel generally contains a small amount of silicon, manganese, sulfur, and phosphorus in addition to carbon. According to the use, carbon steel can be divided into three categories: carbon structural steel, carbon tool steel and free cutting structural steel. Carbon structural steel can be divided into two types: building structural steel and machine-made structural steel. According to the carbon content, the carbon steel can be divided into low carbon steel (wc≤0.25%), medium carbon steel (wc≤0.25%-0.6%) and high carbon steel (wc>0.6%) according to phosphorus and sulfur content. Plain steel is divided into ordinary carbon steel (high in phosphorus and sulfur), high-quality carbon steel (low in phosphorus and sulfur) and high-quality steel (low in phosphorus and sulfur).

2. Carbon tool steel

Carbon tool steel is a kind of high carbon steel which is basically free of alloying elements. Its carbon content is in the range of 0.65% to 1.35%. Its production cost is low, the source of raw materials is easy to obtain, and the machinability is good. It is a widely used steel grade for high hardness and high wear resistance, and is used to manufacture various cutting tools, molds and measuring tools. However, such steels have poor red hardness, that is, when the working temperature is higher than 250 ° C, the hardness and wear resistance of the steel are drastically lowered and the working ability is lost. In addition, carbon tool steels are hard to harden if they are made into larger parts, and are prone to deformation and cracking.

3. Ordinary low alloy steel

Ordinary low alloy steel is a common alloy steel containing a small amount of alloying elements (in most cases, the total amount w is not more than 3%). The strength of the steel is relatively high, the overall performance is relatively good, and has corrosion resistance, wear resistance, low temperature resistance, good cutting performance, welding performance and the like. Under the condition of saving a lot of scarce alloying elements (such as nickel and chromium), ordinary low-alloy steel can be used in the top 1.2-1.3t carbon steel, and its service life and use range is far more than carbon steel. Ordinary low-alloy steel can be smelted in open furnaces and converters by general smelting methods, and the cost is also close to that of carbon steel.

4. Alloy steel for engineering structure

This refers to alloy steel for engineering and building structures, including weldable high-strength alloy structural steel, alloy steel, alloy steel for railways, alloy steel for pressure steel for geological oil drilling, and high-manganese wear-resistant steel.

This type of steel is used as engineering and building structural parts. In alloy steel, the total amount of such steel alloys is low, but the production and use amount is large.

Automotive steel is important, cost considerations are the key

A car is a smart machine, and there are many steel or metal parts. The car body exists as a vehicle that carries all the configurations of the entire car and cab. The body has a very large proportion of the cost for the entire car. Therefore, many car companies will do enough articles on the body to maximize cost savings and increase profit margins. So how is the car body made and manufactured?

The body-in-white is made up of several sheets of steel joined together by welding. However, the steel used in the entire body is a low alloy steel. The biggest advantage of low alloy steel is that it has good processing performance and the steel itself has high mechanical strength. At the same time, low-alloy steel has better corrosion resistance than ordinary steel. In the natural environment, a layer of brown and dense oxide layer will be formed on the surface of low-alloy steel. This layer of oxide is a good way to isolate the internal steel from the outside air. , better play a role in rust prevention.

One of the representatives of low-alloy steel is weathering steel. The biggest characteristic of weathering steel is that it is very resistant to weathering. Weathering steel is usually used at the bottom of the car body, because the bottom of the car is directly exposed, and it is closely related to the ground and the driving environment and is more likely to be corroded by the environment. Therefore, the use of weathering steel is particularly important.

Steel and ocean
Steel and the ocean are inseparable. The versatility of steel allows steel to be used in the ocean in different forms – transporting goods from all over the world to protect the land from the erosion of the ocean and to protect the life of the ocean. The low carbon, durability and high recovery of steel means that the amount of waste is extremely low, which also makes it the most sustainable material.

As a key structural material for offshore engineering equipment, steel is widely used in drilling platforms, production platforms, and submarine pipelines. Due to the long service life, it is necessary to resist the harsh wind and wave conditions for a long time. The cost of underwater repair and maintenance is extremely high. The steel plate used is gradually high strength, high toughness, easy weldability, good corrosion resistance, large thickness, and large normalization. Direction development.

Composition and performance requirements for marine engineering steel

The factors affecting the performance of steel are chemical composition, smelting, and casting, rolling and heat treatment processes, etc., which are mainly composed of chemical components; sulfur and phosphorus content directly affect the performance of the thickness direction of the steel plate. Sulfur is the most severe element of segregation in continuous casting billets. Sulfur can cause the steel to be hot and brittle, causing cracks in the steel during high-temperature forging. Many loose and vent holes are produced during welding.

Therefore, the steel plate for offshore platforms has strict requirements on the content of sulfur and phosphorus, and the content of sulfur is strictly controlled.

Performance requirements for marine engineering steel

Because the offshore platform is immersed in seawater all year round, it has to withstand all kinds of bad sea conditions. Therefore, the technical indexes of steel for offshore platforms are extremely high, not only have high resistance to atmospheric corrosion and seawater corrosion but also require good Mechanics and processing properties, etc. The performance requirements for steel for offshore platforms include:

(1) It has high strength and resists wind current impact above the water surface. It has good resistance to laminar tearing and prevents the steel from tearing when subjected to external forces in the thickness direction;

(2) It has good low-temperature impact performance, and some marine platform steels need to have good impact performance in -60 °C environment, and can be used in an extremely cold environment;

(3) It has good welding performance, and the welded joint performance has the same or similar mechanical properties as the base metal, ensuring the safety of the overall structure of the offshore platform;

(4) Steel purity requirements. Steel needs to have a very low content of impurity elements such as P and S, and has high requirements on the shape, type, and distribution of inclusions, avoiding the fatigue failure of the offshore platform when it is affected by the typhoon and current movement, and guaranteeing life and life. Property security.

The life cycle of steel is a unique material because it is truly recyclable. When steel is recycled, it becomes new steel, not a poor quality product. Since steel does not degrade when recycled, it can be used repeatedly, and steel is the most recycled material in the world. The impact of making steel can be seen as an investment in a material that will be used repeatedly rather than disposable, making steel a highly sustainable material.

Scrap is an essential component of all new steels, so every steel mill is a recycling plant. The value of scrap ensures that it can be recycled whenever it is needed. But in many applications, steel has a long service life, so there is a lot of steel in the world that does useful work. At the same time, global demand for steel is growing. Therefore, even with effective recycling and reuse, scrap accounts for only about one-third of total steel demand.

Steel materials can be easily separated from waste products by magnetic separation, and have high separation, and scrap steel products are recovered due to rising resource prices, and the recovery is also good. However, some impurity elements mixed in during recycling cannot be removed in the steelmaking process. In order to continue recycling, it is necessary to avoid the problem of increased concentration of these elements.

A large amount of steel is produced every year and is widely used in various fields such as bridges, iron towers, buildings, automobiles, machinery, etc., and the material stock of steel materials is formed over time. Since steel materials are easily recycled, these materials have the potential to become secondary resources after completing their mission.

Steel materials can be sorted by magnetic force and are the main raw materials for many products, and they will not deteriorate even when they are idle, so their recycling is excellent.

Steel in travel

For travel, there are many options.
For short trips, the road trip is a good choice. About 40% to 60% of the weight of the car is the weight of steel, which contributes to the safety of the car. A car’s cover parts, body structure parts, body strengthening safety parts, car chassis, seat parts, axle, wheels and so on are all made of steel.
It is because of the automobile with high strength steel, the whole vehicle can ensure the safety of the premise, reduce body weight, reduce fuel consumption, reduce emissions, which let your travel safer.

For long-distance travel, plane greatly improves the travel efficiency of human beings and extends the travel distance, so it has become the first choice of transportation for business travel and international travel.
Every aircraft production, steel mills need to provide high-temperature alloy, titanium alloy, and special high-strength steel landing gear. In the airport, thick plate, paint plate, hot rolled plate, steel pipe, and other steel products have been used.

Railway and steel
In our daily life, steel has become the most commonly used material. Huge machine tools, agricultural machinery, automobiles, trains, ships, heavy tanks, and our pencil cases, iron pots, and pens all need steel to be cast.

The railway probably leaves a mark on everyone’s journey. Once, the green leather car took us to the Quartet, and the sound of the whistle sounded joy and hope.

Nowadays, the green leather compartments in memory are slowly changing. More and more streamlined EMU trains travel between cities. China has built the world’s largest high-speed railway network.

The rapid development of the railway transportation industry puts higher demands on steel, an important raw material for train production. Hot-rolled high-strength weathering steel for railway vehicles has the characteristics of high strength, high toughness, easy welding and easy forming. At the same time, it has good atmospheric corrosion resistance and weather resistance is more than twice that of ordinary structural steel, which greatly prolongs the service life of vehicles. It is widely used in the manufacture of EMU trains, Qinghai-Tibet railway trains and railway freight cars.

The bogie is also one of the most important components on a railway vehicle. It directly carries the weight of the car body and ensures that the vehicle passes smoothly through the curve. At the same time, the various parameters of the bogie also directly determine the stability of the vehicle and the comfort of the ride. Steel for hot-rolled and heavy-plate bogies must have good fatigue resistance and shock resistance.

Whether on the platform or at the airport, whether it is going home or starting, whether it is a gathering or a separate, every time you travel, steel is silently escorting you.

Steel can make car trains, steel can make ship bridges, steel can also build high-rise buildings, and steel can also build blast furnaces.
In the huge steel structure and construction industry, the process of making and welding is quite difficult. The process of cutting, assembling, welding and assembling each profile and every steel plate is inseparable from the efforts of the steelworkers. From our daily life to national security, we cannot do without steel.

Steel applications:

1.Steel in daily life
Our house is made of reinforced concrete, steel is used; our kitchen knives, pots, cookware, etc. are made of steel; our cars are made of steel; our bicycles are made of steel; our home faucets Water heaters and gas pipes are made of steel.

2.Important guarantee of national security
Because steel is used in railways, rail vehicles, ground vehicles, tanks, ships, military camps, military bases, and fortifications, it is widely used both at home and abroad. At the same time, in order to consolidate existing infrastructure and installations, a solid domestic steel industry can provide timely and strong strategic and military support.

Steel, a national security strategy resource, is widely used. In terms of energy facilities, steel is widely used in refineries, oil and gas pipelines, oil storage tanks, power facilities, power transmission towers, and distribution posts. In transportation facilities, steel is widely used in highways, bridges, railways, and public utilities. Transport systems, aircraft, seaports and navigation systems; in health and public safety facilities, in dams and reservoirs, waste and wastewater treatment facilities, public water supply systems and safe housing; in commercial, industrial and public organization complexes Used in manufacturing plants, schools, commercial buildings, hospitals, retail stores, government buildings, etc.

Steel forest-Construction steel
There are many famous and wonderful buildings in the world that are amazing, including the Eiffel Tower in Paris, France, and the small waist in Guangzhou, China. Nowadays, due to the rapid development of the economy, the steel buildings in many big cities are also being Since then, it has formed a “steel forest”. In some relatively large cities, such a view of the steel forest can often be seen. Working people often need to go in and out of high-rise office buildings. These office buildings and many of our urban buildings are inseparable from construction steel.

Steel for construction can be divided into steel for steel structure and steel for civil engineering. Steel for steel structure is mainly low alloy steel (Q345) and ordinary structural steel (Q235) sheet. DIN EN S235JR Mild Steel is the European standard of alloy structural steel, It is equivalent to the Chinese standard of GB Q235B.

China’s construction steel is mainly composed of carbon structural steel and low-alloy high-strength structural steel. High-quality carbon structural steel is also used in cold-drawn carbon steel wire and connecting fasteners. In addition, thickness direction performance steel sheets, weathering steels for welded structures, cast steel, and the like are also used in some cases. Q235 material is mostly used for the main structure of light steel, Q345 material is used for the main structure of heavy steel, Q235 round steel is used for pre-buried anchor bolts, hot-rolled steel bars are mostly used for hot-rolled steel bars, and small-sized steel, channel steel, and H-shaped steel are also used. The civil construction steel is mainly rebar, round steel, wire, and section steel.

Steel is one of the commonly used building materials in construction engineering. The steel used includes carbon structural steel, low-alloy high-strength structural steel; steel used in construction engineering, its mechanical properties, process properties, chemical composition, etc. must meet the corresponding standards.

In the “steel forest” of life, we enjoy the visual perception and the convenience of use brought by various buildings, and we must also protect these buildings and build our good life together.

A good knife needs to use the right tool steel – The kitchen is the warmest corner of Canada, preparing a delicious meal for your beloved family or a day of exhaustion.
As the standard of living continues to improve, the classification and function of the tools are becoming more and more detailed. A good tool will make you fall in love with cooking. Cooking starts with choosing a good tool.
So, what steel is best? Modern industry has created hundreds of high-quality tool steels, and different steels have their own advantages and disadvantages. Which steel should I choose for my knife? What steel can I use to make a good knife? In fact, which steel to choose, this depends on the size of your knife and the use of the scene.

For example, some small tools. The total length is generally no more than 25 cm, and the knife of this size is mostly used for cutting. Take the common fruit knife, it is mainly used for cutting fruit and peeling. It has low requirements on the toughness and strength of steel. On the contrary, it has strict requirements for anti-rust. Therefore, most of these cutting-oriented knives are used. The steel is stainless steel. There are also some small hunting knives that use stainless steel, which is used for peeling and cutting meat. If this type of stainless steel knives and chopping wood are used again, this is considered to be overloaded, and higher strength tool steel is required.

For large knife tools, the total length of the tool is more than 40 cm. The size of the tool is more complicated. The cutting, slashing, and boring are heavy. It is a heavy knife, and its performance requirements for steel are very high. Generally, cutters such as choppers, hatchets, and mountain knives, or axe, the most favored steel is carbon steel. The pure carbon steels like 1040, 1060, and 1095 have a simple internal structure and will be extremely embarrassing after being properly treated. The strength and hardness are extremely high, the cutting performance is excellent, and the impact resistance is good. It is not only tough and durable, but it can also be easily sanded. But its shortcomings are also obvious, it is very easy to rust.

In short, for a knife, the choice of which steel, or first depends on its function, use of the scene, because you need to decide which steel to use.