303 不锈钢 1.4305(UNS S30300)

什么是不锈钢 303 (UNS S30300)1.4305?

不锈钢 303 is the classic free-machining austenitic stainless steel grade. Our material is certified to ASTM F899 (Standard Specification for Wrought Stainless Steel For Surgical Instruments) and ISO 7151 (Surgical Instruments) making it ideal for a range of applications from sanitary wares to micro-mechanical engineering components.

不锈钢牌号 303 can only be strengthened by cold working, not heat treatment, which can lead to the formation of alpha ferrite martensite, considerably increasing its ferromagnetism up to a relative magnetic permeability > 1. The presence of MnS inclusions and of delta ferrite may increasing the difficulty in polishing this grade.

Non-medical versions of 303 stainless steel are available to AMS 5640 in two different types depending on the addition of Sulphur (AMS 5640 类型 1) or Selenium (AMS 5640 类型 2).

303 不锈钢 1.4305 形式s

• Round Bars and Rods

303 stainless steel rods and round bars are often used in applications requiring heavy machining to fabricate parts. They are often used in parts such as screws, gears, nuts and bolts, electrical switchgear components, and aircraft fittings.

• Hex Bars and Rods

303 stainless steel hex bars and rods enable faster machining and lower production costs. Although they have less corrosion resistance than other grades of stainless steel, 303 stainless steel hex bars and rods offer excellent toughness.

Square Bars

Square bars made with 303 stainless steel can resist scaling at up to 871 ℃. Compared to conventional stainless steel square bars, the sulfur component helps improve turning breakup while simultaneously reducing cutting tool drag.

• 扁钢

For parts that require sufficient corrosion resistance and need to be machined, ground, or polished, 303 stainless steel flat bars are useful for many applications.

申请 303 不锈钢

303 stainless steel tube/bar/sheet materials are used in many applications to fabricate a wide range of parts, 包括:

• Bushings
• Shafts
• Nut and bolts
• Gears
• Electrical switchgear components
• Aircraft fittings

乙等值等级 303

欧洲联盟 在	美国 –	日本 他	法国 AFNOR	英格兰 学士	瑞典 SS
X8CrNiS18-9	303	SUS303	Z8CNF18-09	303S31	2346

作品  为了 303 不锈钢等级

机械性能 

年级	303
抗拉强度 (兆帕)	500-750 兆帕
Proof Stress (兆帕)	190 Min MPa
Elongation A5 mm	35 最小 %
Hardness Brinell	230 Max HB

物理特性

Physical Property	价值
密度	8.03 克/立方厘米
熔点	1455 ℃
热膨胀	17.3 x10^-6 /K
弹性模量	193 GPa
导热系数	16.3 瓦/米·K
电阻率	0.72 x10^-6 Ω .m

Corrosion and Oxidisation Resistance of 303

303 Stainless Steel shows good corrosion and oxidisation resistance in mildly corrosive atmospheric environments. Its sulphide inclusions act as pit initiation sites meaning it provides a lot less resistance than 304.

年级 303 should not be exposed to marine or other similar environments, to prevent rapid pitting corrosion.

在 1.4305 303 Stainless Steel provides good oxidisation resistance in intermittent service to 760°C (1400华氏度) and continuous service to 870°C (1,598华氏度)

The use of 303 stainless steel is not recommended in the range of 425-860°C (797-1580华氏度) due to carbide precipitation.

303 is susceptible to sensitisation.

HEAT RESISTANCE

• Good oxidation resistance at temperatures up to 1700oF (927 oC)
• Continuous use at temperatures above 1400oF (760oC) is not usually recommended due to carbide precipitation which can lead to irregular scaling
• Does not have a low carbon content so it is also vulnerable to sensitisation

热处理

ANNEALING

This operation should be carried out at 1850/1950 ºF (1010/1065℃) followed by water quenching. 类型 303, as type 302, should not be subjected to temperatures between 800/1650 ºF (425/900℃) nor slowly cooled through that temperature range, to prevent intergranular corrosion.

FORGING STAINLESS STEEL 303

The piece to be forged should be heated to 2100/2300ºF (1150/1260℃) and not forged below 1700ºF (925ºC.) Parts may be air cooled with no danger of cracking and for maximum corrosion resistance small parts may be water quenched directly off the hammer. Large parts should be annealed after forging.

冷加工

303 is not readily cold workable. Some cold working is possible but sharp bending should not be attempted.

热加工

Fabrication methods like forging, 涉及热加工的应在均匀加热至1149-1260°C后进行. 然后应将制造的部件快速冷却以确保最大的耐腐蚀性.

机械加工性

• 年级 303 stainless steel has excellent machinability. Machining can be enhanced by adhering to the following rules:
• 切削刃必须保持锋利. 钝边导致过度加工硬化.
• 切口应轻但应足够深，以防止材料表面发生加工硬化.
• 应使用断屑器来帮助确保切屑远离工件
• 奥氏体合金的低导热率导致热量集中在切削刃处. 这意味着冷却剂和润滑剂是必要的并且必须大量使用.

焊接

焊接 303 Stainless is not recommended however if this is if unavoidable then use 308L or 309 for electrodes. 303 must be annealed for optimal corrosion protection.

For optimal annealing heat to 1010-1120°C (1850-2048华氏度) and cool rapidly with air or water.

在 1.4305 303 stainless steel cannot be hardened by thermal treatment.°