302HQ უჟანგავი ფოლადი

რა არის უჟანგავი ფოლადი 302HQ？

Grade 302HQ is a specialised wire grade with very wide usage for manufacture of stainless steel

fasteners. The inclusion of 3% copper in the composition reduces the cold work hardening rate

substantially compared to Grade 304. 302HQ is standard for manufacture of self-tapping screws

and light machine screws; it is also used for some bolts, set screws, rivets and specialised

fasteners. It has now totally replaced Grades 384 and 305 for cold heading applications, copper

being a lower cost alternative to their high nickel contents.

The designation 302HQ is not standardised – ASTM specifications list the grade as UNS S30430,

and alternative designations for the same grade include “XM-7”, “304Cu” and “304HQ”. The

standard specification for stainless steel fasteners, ISO 3506, includes 302HQ as an acceptable

composition for fastener grade “A2”; it is commonly produced in strength grades A2-70 and A2-80.

302HQ უჟანგავი ფოლადი 1.4567 მზა პროდუქციის ფორმა

• Coil – Strip
• Foil: Inquire with Ulbrich Stainless Steel Wire – Profile
• Round
• Flat
• Square

განაცხადები 302HQ უჟანგავი ფოლადი

• სურსათის გადამამუშავებელი აღჭურვილობა
• Transport and storage equipment (e.g., beer brewing, milk processing, wine making)
• Kitchen benches, sinks, troughs, equipment, and appliances
• Architectural paneling, railings, and trim
• ქიმიური კონტეინერები, მათ შორის ტრანსპორტირებისთვის
• Heat exchangers
• Woven or welded screens
• ხრახნიანი შეერთებები
• შრინგები

Equivalents of grade 302HQ

ქულა	გაეროს ნომერი	ძველი ბრიტანული		ევრონორმა		შვედური სს	იაპონური JIS
		ბი-ეს	ინგლისური	არა	სახელი
302HQ	S30430	394S17	–	1.4567	X3CrNiCu18-9-4	–	SUS XM7

შემადგენლობა ranges for 302HQ grade of stainless steel

მექანიკური თვისებები 

ქონება	Value
Tensile Strength, min	515 MPa
Yield Strength (0.2% Proof), min	205 MPa
Elongation in 50 mm, min	40%
Hardness, max	201 HB

ფიზიკური თვისებები

ქულა	Density (kg/m3)	Elastic Modulus (GPa)	Mean Coefficient of Thermal Expansion (µm/m/°C)			Thermal Conductivity (W/m.K)		Specific Heat 0-100 °C (J/kg.K)	Electrical Resistivity (nΩ.m)
			0-100 °C	0-315 °C	0-538 °C	at 100 °C	at 500 °C
302HQ	8027	193	17.2	17.8	18.8	16.3	21.5	500	720

კოროზიისადმი მდგრადობა

Equal to or exceeding that of Grade 304. Subject to pitting and crevice corrosion in warm chloride

environments, and to stress corrosion cracking above about 50°C. 302HQ is considered resistant

to potable water with up to about 200mg/L chlorides at ambient temperatures, reducing to about

150mg/L at 60°C.

მდგრადობა სიცხის მიმართ

Good oxidation resistance in intermittent service to 870°C and in continuous service to 925°C.

Continuous use of Grade 302HQ in 425-860°C range is usually safe (free of carbide precipitation)

as the grade has a very low carbon content.

თერმული დამუშავება

Solution Treatment (Annealing) – Heat to 1010-1120°C and cool rapidly. This grade cannot be hardened by thermal treatment.

Cold Work Hardening

302HQ has the lowest work hardening rate of any of the common austenitic stainless steels. This results in a tensile strength increase of approximately 8MPa/%Ra (8MPa increase in tensile strength for each 1% reduction of area of cold work – this data from wire drawing). Even after substantial cold work this grade remains essentially non-responsive to a magnet.

შედუღება

Stainless steel AISI 304CU (1.4567, X3CrNiCu18-9) has good weldability and can be used with many common welding processes such as TIG welding and MIG welding. It can also be used for arc welding, but this should be carried out with appropriate welding parameters to avoid overheating and distortion. To reduce tension and maintain the mechanical properties, the material should be allowed to cool in the air after welding. No heat treatment is required.

დამუშავებადობა

AISI 304CU (1.4567) stainless steel is generally machinable, but this material hardens during machining. Therefore, care must be taken to select a sufficient cutting depth. In addition, suitable tools and coolants should be used to prevent overheating and extend tool life.