scholarly journals Heat Treatment of Cold Formed Springs Made from Oil Hardened and Tempered Spring Steel Wire

2017 ◽  
Vol 892 ◽  
pp. 16-20
Author(s):  
Veronika Geinitz ◽  
Ulf Kletzin
Keyword(s):  
Heat Treatment ◽  
Mechanical Characteristics ◽  
Steel Wire ◽  
Spring Steel ◽  
Treatment Technology ◽  
Cold Forming ◽  
Steel Wires ◽  
Heat Treatment Technology ◽  
Compression Springs

The heat treatment after cold forming is used to decrease the residual stresses of springs, but the mechanical characteristics of the spring steel wires alters, too. This presentation describes the influence of the heat treatment technology (oven equipment, temperature, duration,…) to the properties and quality of helical compression springs made from oil hardened and tempered spring steel wire.

VHCF Strength of Helical Compression Springs - Influence of Heat Treatment Temperature before Shot Peening

2015 ◽  
Vol 664 ◽  
pp. 140-149
Author(s):  
Isabell Brunner ◽  
Desislava Veleva ◽  
Jörg Beyer ◽  
Matthias Oechsner
Keyword(s):  
Heat Treatment ◽  
Crack Initiation ◽  
Shot Peening ◽  
Heat Treatment Temperature ◽  
Fracture Behaviour ◽  
Steel Wire ◽  
Fatigue Tests ◽  
Treatment Temperature ◽  
Spring Steel ◽  
Compression Springs

Previous fatigue tests show that the heat treatment temperature has a significant influence on high cycle fatigue behaviour of helical compression springs. In order to investigate the effect of the heat treatment temperature on the fracture behaviour and the cyclic life, fatigue tests in the very high cycle regime (VHCF) were conducted.The tested springs were manufactured from oil hardened and tempered SiCr-alloyed valve spring steel wire with a diameter of d = 1.6 mm. After winding and grinding of the spring endings, the springs were heat treated at either 360°C or 400°C for 30 minutes. In order to generate compressive residual stresses in the surface area, the springs were shot peened. After shot peening, the springs were again annealed at 240°C for 30 minutes.Fatigue tests were conducted at 40 Hz using a special spring fatigue device. Up to 900 springs were tested simultaneously at various stress levels to 5∙108or 109cycles. Fractured springs were investigated by means of a stereomicroscope as well as a scanning electron microscope to analyse the fracture behaviour and failure mechanisms. The vast majority of the springs show crack initiation at the surface at the inner side of the coil. Less frequently, crack initiation occurs at subsurface locations. Our results show that heat treatment at a temperature of 360°C leads to four times more subsurface cracks than at a temperature of 400°C and reduces the overall fatigue life time.

First Paper: The Effect of Heat Treatment on the Ductility of Alloy Steel Wires in a Cold Heading Process

1969 ◽  
Vol 184 (1) ◽  
pp. 875-884 ◽  
Author(s):  
P. F. Thomason
Keyword(s):  
Heat Treatment ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Steel Wire ◽  
Groove Depth ◽  
Air Cooling ◽  
Steel Wires ◽  
Fracture Crack ◽  
Different Types ◽  
Process Annealing

Longitudinal grooves of various depths ranging from 0.001 in to 0.011 in were machined on the cylindrical surface of steel slugs prior to carrying out an automatic two-stage transfer heading operation. The longitudinal grooves were used to estimate the ‘critical groove depth’, which was defined as the depth of longitudinal groove that contained a ductile fracture crack just on the point of ‘opening out’ at the end of the heading process, thus giving a measure of the ductility of the wire. A half-replicate of a two-level factorial experiment was carried out to assess the effects and interactions of annealing temperature, annealing time, cooling rate and ageing temperature on the ductility of four different types of 1/2 in diameter cold heading steel wire. The results show that certain types of steel wires have optimum ductility in the ‘as-received’, cold-drawn, state. Other types of steel are shown to respond favourably to process annealing treatments, in which case annealing at 700°C for 1 hour followed by air cooling should give optimum ductility. It is shown that there is no general correlation between decreasing hardness and increasing ductility for steel wire.

Improving in cold resistance of castings made of 20GL type steels

2021 ◽  
pp. 195-202
Author(s):  
A.F. Degtyarev ◽  
V.N. Skorobogatykh ◽  
V.V. Nazaratin ◽  
F.A. Nuraliev ◽  
A.S. Kaftannikov
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Cold Resistance ◽  
High Impact ◽  
Reliable Operation ◽  
Treatment Technology ◽  
Heat Treatment Technology ◽  
High Impact Strength ◽  
Rational Control ◽  
Chemical And Phase Compositions

The analysis of the literature data on the steels used for the manufacture of castings operating at negative temperatures and the technology of their manufacture is carried out. The effect of chemical and phase compositions on the strength and impact strength characteristics is revealed. The rational technology for manufacturing of these castings is considered. Methods for obtaining of high impact strength of castings made of 20GL type steels at –40...–60 °C temperatures are given. Modification, microalloying and rational modes of heat treatment are used as methods of rational control of the steels structure. The heat treatment technology of castings, which provides the necessary package of properties and reliable operation, is proposed.

Analysis of Material and Heat Treatment of the High-Pressure Fracturing Pump Valves

2011 ◽  
Vol 339 ◽  
pp. 502-505
Author(s):  
Qi Ming Yang ◽  
Li Jie Yang
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Working Life ◽  
Nickel Steel ◽  
Treatment Technology ◽  
The Core ◽  
Heat Treatment Technology ◽  
Heat Hardening ◽  
Wear And Tear ◽  
Core Hardness

Fracturing pump valve's failure, except wear and tear factors, and also decided by the scope of it's contact stress, material and heat treatment in technology. Through the analysis of these, some conclusions had been found: The content of remnant austenite would be affected the performance of wear resistance, and the core hardness would be directly affected the working life of it. If the choice of the material and heat treatment technology was not been suitable, and the core intensity was not enough, it could loss the capability of sealing. According to the failure mechanism, used low chrome(nickel) steel, and the heat treatment of carburize+heat hardening+low-temperature tempering was reasonable.

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