... steel is a kind of common stainless steel materials, rust protection performance is better than 200 series stainless steel materials. Resistance to high temperature also is better, generally use temperature limit is less than 650℃. 304 stainless steel... more
Place of Origin:Introduction to the 304 304 stainless steel is a kind of common stainless steel materials, rust protection performance is better than 200 series stainless steel materials. Resistance to high temperature also is better, generally use temperature limit is less than 650 ℃. 304 stainless steel has good corrosion resistance and better performance of resistance to intergranular corrosion. For oxidizing acid, the experiment concluded that: in the concentration ≤65% nitric acid below the boiling temperature, 304 stainless steel has a strong corrosion resistance. Also has good corrosion resistance ability for most of alkali solution and organic acid and inorganic acid . Density is 7.93 g/m³ 304 is equivalent to 06Cr18Ni9【according to GB/T 20878-2007 has been changed to 06Cr19Ni10】stainless steel。 304 is one of the most common stainless steel, also known as the 18/8 stainless steel. It’s superior to the corrosion resistance than 430 stainless steel, but the price is much cheaper than 316 stainless steel, so it’s widely used in life, for example, some high-grade stainless steel tableware, outdoor stainless steel railings, etc. 304 stainless steel is a kind of generality material, it is widely used to produce good comprehensive performance, corrosion resistance and formability of equipment and parts. In order to keep the inherent corrosion resistance of stainless steel, steel must contain more than 16% of chromium, more than 8% of the nickel content. 304 stainless steel is a grade made according to the ASTM standard. 304 stainless steel mechanical property Tensile Strength: σb (MPa)≥520 Offset Yield Strength: σ0.2 (MPa)≥205 Elongation: δ5 (%)≥40 Reduction of area: ψ (%)≥60 Hardness：≤187HB;≤90HRB;≤200HV 304 stainless steel product standards In 304 the most important element is the Ni and Cr, but are not just limited to these two elements. The specific requirements prescribed by the standard. Industry common determining condition think that as long as Ni content is more than 8%, Cr content is more than 18%, it can be considered as 304 stainless steel. This is why in stainless steel industry will call this type of 18/8 stainless steel. In fact, the relevant product standards have very clear provisions for 304, but these products standard have some differences for different shapes of stainless steel. Here are some of the common product standards and testing. Judge To determine whether a material is 304 stainless steel or not, must meet the requirements of each element in the product standard, as long as there is a element do not accord with, cannot be called 304 stainless steel. 1、ASTM A276（Standard Specification for Stainless Steel Bars and Shapes） 304 C Mn P S Si Cr Ni % 0.08 2.00 0.045 0.030 1.00 18.0–20.0 8.0-11.0 2、ASTM A240（Chromium and Chromium-Nickel Stainless Steel Plate,Sheet, and Strip for Pressure vessels and for General Applications） 304 C Mn P S Si Cr Ni N % 0.07 2.00 0.045 0.030 0.075 17.5–19.5 8.0–10.5 0.10 3、JIS G4305（cold-rolled stainless steel plate, sheet and strip） SUS 304 C Mn P S Si Cr Ni % 0.08 2.00 0.045 0.030 1.00 18.0–20.0 8.0-10.5 4、JIS G4303 （Stainless steel bars） SUS 304 C Mn P S Si Cr Ni % 0.08 2.00 0.045 0.030 1.00 18.0–20.0 8.0-10.5 Above four standard just some common standard, Actually ASTM and JIS referred to 304 is more than this standard. Each standard have different demand for 304, so if you want to determine whether a material is 304 or not, need accurate it expression. Application range System description: 304 is one of the most widely used kind of chrome - nickel stainless steel. as a kind of widely used steel it has good corrosion resistance, heat resistance, low temperature strength and mechanical properties; Stamping, bending, etc. Hot workability is good, no heat treatment hardening phenomenon (non-magnetic, using temperature 196 ℃ ~ 800 ℃). In the atmospheric can corrosion resistance, if it is industrial atmosphere or heavily polluted area, then need to clean in time to avoid corrosion. Suitable for use in food processing, storage and transportation. Has a good processing performance and weldability. Can produce plate heat exchanger, corrugated pipe, household goods (grade 1, 2, tableware, cabinets, indoor pipeline, water heater, boiler, bath), auto parts (windshield wiper, muffler, molded products), medical appliances, building materials, chemical, food industry, agriculture, Marine parts, etc. 304 stainless steel as approved by the national food grade stainless steel. Most of the requirements is to maintain the original appearance of the building for a long time. When determining choose which stainless steel type, main consideration is required in the aesthetic standards, it’s area atmospheric corrosion, and clean up the system adopt. However, other applications is more and more only quest for structural integrity or impervious. For example, industrial building roof and side wall. In these applications, the owner of the construction costs may be more important than aesthetic, even the surface is not very clean. Use 304 stainless steel in dry indoor environment the effect is quite good. However, in the country to maintain its appearance, cleaning should be carried out regularly in the outdoor. In serious pollution industrial area and coastal regions, the surface is very dirty, and even produce rust. But in order to get the aesthetic effects in outdoor environments, we need to use nickel stainless steel. So, 304 stainless steel is widely used in curtain wall, side wall, roof and other construction purposes, but in serious corrosive industrial or sea atmosphere, had better use 316 stainless steel. Stainless steel sliding door, now, people have fully realized the advantages of using stainless steel in structures. There are several design principles include the 304 and 316 stainless steel. Because "Duplex" stainless steel 2205 have fused together the good resistance to atmospheric corrosion resistance and high tensile strength and elastic limit strength, so, in Europe standard also includes this kind of steel . Product shape, in fact, stainless steel is produced by the standard shape and size of metal, and there have many special shapes. The most commonly used product is made of sheet and strip, also used the heavy plate to produce special products, for example, production of hot-rolled steel structure and steel extrusion structure. And there are circular, elliptical, square, rectangular and hexagonal welded pipe or seamless steel tube and other forms of product, including section bar, bars, wire rod, and casting. 304 stainless steel rust Rusty phenomenon in a 304 stainless steel material, there may be several reasons: Chlorid ion Chloride ions is widespread, such as in salt/water/wind,etc. Stainless steel in the environment of the presence of chloride ions, corrosion very soon, even quick than ordinary low carbon steel. So there have requirements for use of stainless steel environmental, and need often to wipe, remove dirt, keep clean and dry. (so you can set a "misuse" for it.) There has a example in America: a company use a oak container holding a chlorine ion solution, the container has been used more than hundred years, it plans to change in the ninety, because the oak material not enough modern, so they use stainless steel to replace it, after16 days the container leakage due to corrosion. solution treatment Alloying elements have not dissolve into the matrix,result in matrix organization low alloy content, poor corrosion resistance.