Physical Properties of Stainless Steel and Carbon Steel

Slightly higher than the density of carbon steel of ferrite and martensite stainless steel, but slightly lower than the austenitic stainless steel; resistance rates of carbon steel, ferrite size, martensitic and austenitic stainless steel Sort Ascending; linear expansion coefficient The sorting is also similar to carbon austenitic stainless steel of the highest minimum; carbon steel, ferritic and martensitic stainless steel body magnetic, austenitic stainless steel non-magnetic, but the cold hardening generated during phase transformation into the clan will have a magnetic, heat treatment method can be used to eliminate the martensite and the restoration of its non-magnetic.

Compared to Austenitic Stainless Steel and Carbon Steel, have the following characteristics:

1 high resistivity, about 5 times that of carbon steel.
2 The large linear expansion coefficient than the carbon steel is 40%, and with increasing temperature, linear expansion coefficient values are correspondingly high.
3 low thermal conductivity, carbon steel is about 1/3.

Whether stainless steel or heat-resistant steel, austenitic steel of the best properties of both adequate strength as well as excellent hardness is not high plasticity, which is widely used because they are one. Austenitic stainless steel with the vast majority of other metal material similar to the slow reduction of its tensile strength and toughness, there is no brittle transition temperature. So stainless steel at low temperature to maintain sufficient plasticity and toughness.

The so-called duplex stainless steel is quenched in the solid phase and austenitic in the ferritic phase half and half, the general content of a minimum of 30% may be achieved.



As the two-phase characteristics of the organization, through proper control of chemical composition and heat treatment process, so that both DSS ferritic stainless steel and austenitic stainless steel advantages.

Stainless steel application in various fields

1. 1960 - 1999 of about 40 years, Western countries jumped from 2.15 million tons to 17.28 million tons, an increase of about 8 times the average annual growth rate of about 5. 5%. Stainless steel is mainly used for
 
Stainless steel
Kitchen, appliances, transportation, construction, civil engineering fields. Area in the kitchen appliances, washing tank and the main electrical, gas water heater, home appliances are mainly automatic washing machine drum. Energy saving and recycling from the environmental point of view, the demand for steel is expected to further expand.

Mainly in the field of transport vehicles and railway vehicles exhaust system, stainless-steel exhaust system for each vehicle in at about 20-30kg, the world's annual demand of about 100 million tons, which is the largest steel applications.

In the construction sector, the recent sharp increase in demand, such as: Singapore subway station guards, using about 5,000 tons of stainless steel exterior decoration materials. Another example of Japan after 1980, for construction of stainless steel increased by about 4 times, mainly for the roof of the building materials inside and outside decoration and structure. 80 years, coastal areas in Japan using 304-type material as the roofing material without paint from rust to consider gradually changing for the use of painted steel. Into the 90's, high corrosion resistance developed more than 20% of high Cr ferritic stainless steel system, is used as roofing materials, and aesthetics in order to develop a variety of surface finishing techniques.

In the civil area, Japan, dam water absorption tower using stainless steel. Europe's cold regions, in order to prevent freezing of highways and bridges need to spread salt, which accelerated the corrosion of steel, so use stainless steel. The road in North America, nearly three years, about 40 of stainless steel reinforcement, the use of each office as 200-1000 tonnes of stainless steel in this area in the future market will do it.

2. Future expansion of stainless steel applications, the key is environmental protection, long life and popularity of IT.

For environmental protection, the first point of view of environmental protection from the atmosphere, the high temperature for the suppression of dioxin waste incineration plant occurs, LNG power generation facilities and the efficient use of coal thermal power generation equipment, high temperature corrosion of stainless steel demand will increase. There are estimated to be in the 21st century into practical application of fuel cell vehicles will use the stainless steel battery shell. Point of view of environmental protection of water quality in water supply, wastewater treatment device has excellent corrosion resistance of stainless steel will expand demand.

On long-life, existing in Europe, bridges, highways, tunnels and other facilities, the application of stainless steel is increasing, this trend is expected to be throughout the world. There are residential buildings in Japan generally short life span of 20-30 years in particular, waste material handling as a major problem. Recently as the target life of 100 buildings began to appear, so that the material has excellent durability needs to rise. Environmental point of view from the Earth, long life to reduce civil, construction waste materials at the same time, it is necessary to introduce a new concept from the design stage of how to reduce maintenance costs.

The popularity of IT in the IT development and universal process, functional materials in the device very useful in hardware for high precision, high performance materials require very large. Such as: mobile phones and omputer components, the flexible application of the stainless steel of high strength, flexibility and non-magnetic and other properties, makes the application of stainless steel expanded. There are a variety of substrates in the semiconductor and manufacturing equipment, with good cleanliness and durability of stainless steel played an important role.

Stainless steel has many other metals do not have outstanding performance, is an excellent durability and recycling of materials, the corresponding changes of the times in the future, stainless steel is widely used in various fields.

Carbon is one of the main elements of industrial steel, steel performance and organization to a large extent determined by the content of carbon in the steel and its distribution in the form, the impact of carbon in steel is particularly significant. Carbon in the stainless steel impact on the organization mainly in two aspects, one is stable austenite carbon element, and the extent of the role of large (approximately 30 times for nickel), on the other hand because the affinity of carbon and chromium is large, and the formation of chromium - series of complex carbides. Therefore, intensity and decay candle performance both in terms of the role of carbon in the stainless steel is contradictory.