Established in 1992, Zhejiang Pengye Steel Pipe Co., Ltd. is a joint-stock company specializing in various stainless steel seamless pipes, square pipes, welded pipes, special shape pipes and mirror-surface pipes. Our headquarters is located in the Songyang Industrial Zone of Zhejiang, with subsidiary company of Wenzhou Pengye Steel Pipe Co., Ltd. and the branch factory.


Occupying 46,000 square meters and with the assets of USD15 million, our annual output of stainless steel products can reach ten thousand tons. Our products are widely used in chemical industry, petroleum, medicine, food, machinery, construction, space, war industry, hardware, boilers, heat exchangers, ship and electricity. Our company consists of more than 20 selling companies and special distribution companies at home, and has many large-scale users. Our products are well sold all over the world.



Our company has abundant technical strength, advanced production equipment and complete test methods. The demand of products rises year by year and company's scale expands constantly. Our products are popular among domestic and international clients.

01) Commodity: seamless austenitic stainless steel pipes

02) Process method: cold drawn/cold pilgered

03) Surface finish: annealed and pickled

04) Material: TP304, TP304L, TP310/S, TP316L, TP304/304L, TP316/316L dual grade, TP321,
05) Standards: ASTM (ASME) SA/A312/M

06) Size:
        a) NPS: 1/8" to 8"
        b) Schedule: 10/10S,40/40S, 80/80S acc. to ANSI B36.19/36.10
        c) O.D.: 10.27mm to 630.10mm
        d) W.T.: 1.24mm to 40mm

07) Length: Max.13 meters

08) Delivery conditions: solution annealed, pickled, grey white, with plain ends

09) Applications: for fluid and gas transport; structure and machining

10) packing: in seaworthy wooden cases or in bundles

11) Min order quantity: upon negotiation

12) Delivery date: Min. 45 days

1. OD: 6 - 830mm, thickness: 0.5 - 40mm
2.Material: 321, 304, 304L, 316, 316L, 310S
3. Standard: ASTM, DIN, JIS
4. Application: chemical industry, petroleum, medicine, food, machinery, construction;
space, war industry, hardware, boilers, heat exchangers, ships and electricity
5. Custom specifications available

1. OD: 6 - 830mm, thickness: 0.5 - 40mm
2.Material: 321, 304, 304L, 316, 316L, 310S
3. Standard: ASTM, DIN, JIS
4. Application: chemical industry, petroleum, medicine, food, machinery, construction;
space, war industry, hardware, boilers, heat exchangers, ships and electricity
5. Custom specifications available

Stainless steel  - History

Background

The "discovery" of stainless steel occurred in the 1900 to 1915 time period. However, as with many discoveries, it was the accumulated efforts of several individuals that actually began in 1821. That year a Frenchman named Berthier found that iron when alloyed with chromium was resistant to some acids. Others studied the effects of chromium in an iron matrix, but using a low percentage of chromium. To be stainless steel, the chromium content needs to be at least 10.5%. In 1872, Messrs. Woods and Clark applied for a British patent for what they identified as an acid and weather resistant alloy containing 30 to 35% chromium and 1.5 to 2% tungsten. Then, in 1875, another Frenchman named Brustlein recognized the importance of carbon levels in addition to chromium. Stainless steels need to have a very low level of carbon at 0.15%. While many others investigated the chromium/iron composition, the difficulty in obtaining the low carbon levels persisted for many years until low carbon ferrochrome became commercially available.

Discovery

In 1904, Leon Guillet published research on alloys with composition that today would be known as 410, 420, 442, 446 and 440-C. In 1906, he also published a detailed study of an iron-nickel-chromium alloy that is the basic metallurgical structure for the 300 series of stainless steel. In 1909, Giesen published in England a lengthy account on the chromium-nickel (austenitic 300 series) stainless steels. Also in England and France, Portevin published studies on an alloy that today would be 430 stainless steel. In Germany, in 1908, Monnartz & Borchers found evidence of the relationship between a minimum level of chromium (10.5%) on corrosion resistance as well as the importance of low carbon content and the role of molybdenum in increasing corrosion resistance to chlorides.

Industrial Development

Harry Brearley, chief of the research lab run jointly by John Brown & Co. and Thomas Firth & Sons, is generally accredited as the initiator of the industrial era of stainless steel. Most of his work was on 430 (the chemical analysis was patented in 1919). The first product was table cutlery and it is still used today.

Note: There were many more investigators and researchers who played important roles in the development of stainless steel; too numerous to mention here. A very good historical account is given in the book "Stainless Steels" by Carl A. Zapffe.

INTRODUCTION
What is a Standard Finish?
“Standard” finishes are produced on an on-going basis. They are generally available off the shelf or can be obtained with a short lead-time. They are the finishes that are used for most stainless steel applications. Standard finishes are categorized as either “Mill” or “Polished”.

“Mill” finishes are the least expensive finish option. There are both hot- and cold-rolled mill finishes, and, as this description implies, their appearance is produced at least in part by passing the stainless steel through special rolls or dies. The reflectivity of these finishes varies from dull to mirror-like. These finishes become less uniform in appearance with increasing product thickness or diameter.

“Polished” finishes are produced by mechanically abrading the surface with a series of gradually finer abrasives or a special rolling procedure that simulates the appearance of mechanical abrasion. The smoothest polished finishes are buffed after mechanical polishing to produce a mirror-like appearance.

“Special” Finishes include finishes that are generally used when aesthetic appearance is important and for specialized industrial applications. This category includes non-directional scratch patterns, swirls, ground circles, embossed and coined textures, and various coloring and coating methods.