1: Brief Introduction Of 309/309S stainless steel  
Alloy 309/309S (UNS S30900/S30908) austenitic stainless steel is typically used for elevated temperature applications. Its high chromium and nickel content provides comparable corrosion resistance, superior resistance to oxidation, and the retention of a larger fraction of room temperature strength than the common austenitic Alloy 304.
Alloy 309 (UNS S30900) is an austenitic stainless steel developed for use in high temperature corrosion resistance applications. The alloy resists oxidation up to 1900°F (1038°C) under non-cyclic conditions. Frequent thermal cycling reduces oxidation resistance to approximately 1850°F (1010°C).
Because of its high chromium and low nickel content, Alloy 309 can be utilized in sulfur containing atmospheres up to 1832°F (1000°C). The alloy is not recommended for use in highly carburizing atmospheres since it exhibits only moderate resistance to carbon absorption. Alloy 309 can be utilized in slightly oxidizing, nitriding, cementing and thermal cycling applications, albeit, the maximum service temperature must be reduced.
When heated between 1202 - 1742°F (650 - 950°C) the alloy is subject to sigma phase precipitation. A solution annealing treatment at 2012 - 2102°F (1100 - 1150°C) will restore a degree of toughness.
309S (UNS S30908) is the low carbon version of the alloy. It is utilized for ease of fabrication. 309H (UNS S30909) is a high carbon modification developed for enhanced creep resistance. It most instances the grain size and carbon content of the plate can meet both the 309S and 309H requirements.
Alloy 309 can be easily welded and processed by standard shop fabrication practices.
Other Grades:
201,202,21-4N,301,302,301L,303,303Se,304,304L,304H,304LN,304N,305,S38400,308,309,309S,310,310s,
316,316L,316H,316Ti,316N,316LN,317,317L,317LMN,317LN,321,321H,347,347H,S3100,S31803,S3205,
S32304,S31200,S31260,S32507,405,409,429,430,430F,434,444,403,410S,410,416,420,420F,431F,440A
440B,440C,440F,610,630,631,632,635,660,Alloy 200,Monel 400 ,Alloy K-500 ,Inconel 600 , Incconel 601,
Inconel 625 , Inconel 718 , Alloy 800 ,Alloy 800H,Alloy 800HT,Inconel 825,Alloy 276, Alloy 20, Alloy 59
2: Chemical Composition  3: 309/309S Stainless Steel Round Bar Process

4: 309/309S Stainless Steel Round Bar Diameter Tolerance 

5: About us 
Tianjin Zhongyantiancheng Steel Co.,Ltd(short for ZYTC ) is a professional manufacturer and exporter of steel products in China, located in Tianjin Beichen District, having the biggest port in North China.
With 20 years of development, the group has become the leader in steel, product variety, complete specifications and so on in North China market, large inventories more than 100,000 tons are maintained all the time.
ZYTC is specialized in steel products, especially Stainless steel pipe,Stainless steel bar,Stainless steel plate (TG,KSK,BG,Krupp), Round bar(SHOUGANG,DAYE), Spiral pipe(LIDA), Aluminum steel plate,Aluminum pipe ,Copper and so on . 
ZYTC has cooperated with Tianjin Seamless Steel Tube Plant(TPCO), Baotou Steel Pipe Plant, Chengdu Steel Pipe Plant, Anshan Steel Pipe Plant,Baoshan Steel Pipe Plant and other steel pipe plants.Round bar cooperated with Beijing shougang goup,Tonggang steel group, Daye steel bar group ,Benxi bengang group an so on , Baotai titanium group,Baoji Lixing group,Stainless steel plate cooperated with Shanxi TAIGANG Steel Plate grouop,Baogang group,Shanghai Kelubo group ,and Puxiang steel group. all these corporations mentioned above are our shareholder partners. 
ZYTC principle is: supplying the best products and service,being the best supplier.
The company can make steel product according to particular specifications and materials. ZYTC will perfect our quality management system and supply products of high quality to our customers.
We are all looking forward to establishing business relationships with customers all over the world!* More than 20 years experience in stainless and aluminum steel fields.
* Samples available.
* Specialist metallurgic advice and flexible service.
* High level of expertise, in-depth product knowledge.
* Competitive price, high quality,rich experiences and high reputation
* Delivered on time.
* Good after-sale service.
* Well recognized and trusted by customers.

7: Contact Us