深圳市中科五金制品有限公司

One, the current market standard parts are mainly carbon steel, stainless steel, copper and three kinds of materials.

(a) carbon steel. We distinguish between low carbon steel with the content of carbon in carbon steel, medium carbon steel and high carbon steel and alloy steel.

1, low carbon steel C% is less than or equal to 0.25% domestic is often referred to as A3 steel. Foreign basic called 1008101510181022. Mainly used for grade 4.8 and grade 4 bolts nuts, such as a small screw no hardness requirements of the product. (Note: drilling screws mainly used 1022 materials.)

In 2, 0.25%<C% < 0.45% domestic carbon steel is usually called No. 35, No. 45 steel, foreign basic called 1035, CH38F, 1039, 40ACR. Mainly used for class 8, class 8.8 bolts and nuts level 8.8 inner six angle products.

3, the high carbon steel C%>0.45%. Currently on the market basically no use

4, alloy steel: addition of alloying elements in plain carbon steel, add some special properties of steels: such as 35, 40 Cr Mo, SCM435, 10B38. Fang Sheng screw mainly use SCM435 chrome molybdenum alloy steel, main components are C, Si, Mn, P, S, Cr, Mo.

(two) stainless steel. Performance levels: 45, 50, 60, 70, 80

The main points of austenitic (18%Cr, 8%Ni) with good heat resistance, good corrosion resistance, good weldability. A1, A2, A4

13%Cr Martensitic, corrosion resistance is poor, high strength, good abrasion resistance. C1, C2, C4 ferritic stainless steel. 18%Cr upsetting performance, strong corrosion resistance than martensite. Currently on the market for imported materials mainly Japanese products. According to the level of SUS302, SUS304, SUS316 main points.

The serial number of a class can choose material

1 4.8 level six angle bolt 1008K 1015K 1010

2 6.8 level six angle bolt 103210351040 CH38F 1039

3 8.8 level six angle bolt 1035ACR (under M10) 1040ACR (M12 CH38F 1045ACR 10B21 10B33 1039 or above) 10B38

4 8.8 stage inner six angle bolt CH38F 1039 10B21 (M10-M12) 10B33 (M14) 10B38 (M12-M24) 10B21

Level 510.9 angle bolt 1045ACR 10B38 six

6, 8 of grade nut 1008K 1010

7 8 level nut 1015 (M<16) CH38F (M = 16)

8 10 level nut CH38F 1039 10B21 10B33

9 12 level nut 1039 10B21 10B33 10B38

10 screws carriage 100810101015

11 six angle edge is a convex bolt CH38F 1039 10B21 10B33 10B38

12 six angle wood screws 1008K 1010

13 self tapping screws, drywall screw

Drilling screws, screw 10181022 CH22A splint

14 machine screws and furniture screws 10081010

(three) copper. Commonly used materials for brass... Zinc and copper alloy. The market of standard parts with H62, H65, H68 copper.

Plate element used by two, steel products:

Effects of three various kinds of elements, material properties of steel:

1, carbon (C): to improve the steel strength, especially its heat treatment performance, but with the increase in carbon content, plasticity and toughness, and can affect the performance of cold heading steel parts and welding performance.

2, Mn (Mn): improve the steel strength, and hardenability is improved to a certain degree. That increases the hardened in. That increases the hardened infiltration intensity in quenching, manganese can improve surface quality, but too much manganese on ductility and weldability of adverse. And will affect the control plating coating.

3, nickel (Ni): to improve the steel strength, improve the low temperature toughness, improve the atmospheric corrosion resistance ability, and can guarantee the heat stable treatment effect, reduce the effect of hydrogen embrittlement.

4, chromium (Cr), can improve the hardenability, improve wear resistance, improve the corrosion resistance, and has remained conducive to high temperature strength.

5, molybdenum (Mo): to help control the hardenability of steel, reduce the sensitivity of temper brittleness, has great influence on improving the high temperature tensile strength.

6, the boron (B): can enhance the hardenability, and helps to make low carbon steel to produce the desired response to heat treatment. 8k1Dj1@0z

7, alum (V): refine austenite grain, toughness.

8, the silicon (Si): to ensure the steel strength, appropriate content can improve the plasticity and toughness of steel parts.

Brief introduction of the four characteristics, a stainless steel material (304, 316)

(a) the three are made of austenitic stainless steel 300 series, its chemical composition is as follows: V 4C [(&

The name of the C Si Mn P S Ni Cr Mo Cu

304M < 0.06 < 1 < 2 < 0.045 < 0.03 8.91-10.0 18.0-20.0 00 +: 7L= N#!

316 = 0.03-0.06 = 1 = 2 = 0.045 = 0.03 10.0-14.0 16.0-18.0 2.0-3.0 0

304HC < 0.08 < 1 < 2 < 0.045 < 0.03 8.0-10.5 17.0-19.0 0 1.0-3.0

(two) the relationship between main chemical components and performance of stainless steel.

1, the carbon C can increase the hardness and strength, high content will reduce its ductility and corrosion resistance

2, chromium Cr can increase the corrosion resistance, oxidation resistance, so that the grain refinement, increase the strength, hardness and wear resistance

3, the Ni Ni can increase the high temperature strength, corrosion resistance, reduce the rate of cold work hardening

4, Mo increased the strength of molybdenum, oxide and seawater corrosion resistance and excellent

5, copper Cu for processing, reducing the magnetic

(three) the other properties of materials

1 more than the normal state without magnetic material. 304M cold working after a slight magnetic (about 1.6u-2.0u); 304HC (about 1.01u-1.6u); magnetism material 316 magnetic after cold working less than 1.01u.

2, the ductility of the materials are good, easy processing, tensile strength, yield strength, can meet the requirements. (Ts min 700N/mm Ys, the tensile strength, yield strength of Min 450N/mm)

(four) conclusion

1, 304M, 304HC, 316 of three kinds of material is one of the 300 series austenitic stainless steel material is currently the most widely used. The material is obvious difference: after cold working material magnetic 316<304HC<304M. 316 material resistance to chemical corrosion, pitting corrosion and anti seawater corrosion resistance compared to 304M and 304HC to be good.

2, in short, stainless steel standard parts characteristics for corrosion resistance, beautiful appearance and sanitation, but its strength and hardness under normal circumstances is equivalent to the carbon steel (grade 6.8) the stainless steel products should not impact, beating, pay attention to the maintenance of its surface