GB/T 38443-2019 English PDF (GBT38443-2019)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 38443-2019
Historical versions: GB/T 38443-2019
Preview True-PDF (Reload/Scroll if blank)

GB/T 38443-2019: GH4145 alloy bars and forgings -- General specification
GB/T 38443-2019
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.120.40
J 32
GH4145 alloy bars and forgings - General
specification
ISSUED ON: DECEMBER 31, 2019
IMPLEMENTED ON: JULY 01, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Terms and definitions ... 6 
4 Technical requirements ... 6 
5 Test method ... 11 
6 Inspection rules ... 11 
7 Marking and packaging ... 12 
8 Quality certificate ... 13 
GH4145 alloy bars and forgings - General
specification
1 Scope
This Standard specifies the technical requirements, test methods, inspection
rules, marking and packaging, and quality certificates of GH4145 alloy bars and
forgings.
This Standard applies to GH4145 alloy bars and forgings whose bar diameter
is 50 mm ~ 250 mm and forging section thickness is not greater than 250 mm.
2 Normative references
The following documents are indispensable for the application of this document.
For dated references, only the dated version applies to this document. For
undated references, the latest edition (including all amendments) applies to this
document.
GB/T 223.4, Iron, steel and alloy - Determination of manganese content -
Potentiometric or visual titration method
GB/T 223.8, Methods for chemical analysis of iron, steel and alloy - The
sodium fluoride separation - EDTA titration method for the determination of
aluminium content
GB/T 223.11, Iron, steel and alloy - Determination of chromium content -
Visual titration or potentiometric titration method
GB/T 223.18, Methods for chemical analysis of iron steel and alloy - The
sodium thiosulfate separation iodimetric method for the determination of
cupper content
GB/T 223.23, Iron, steel and alloy - Determination of nickel content - The
dimethylglyoxime spectrophotometric method
GB/T 223.40, Iron, steel and alloy - Determination of niobium content by the
sulphochlorophenol S spectrophotometric method
GB/T 223.42, Methods for chemical analysis of iron, steel and alloy - The
anion-exchange separation-bromopyrogallol red photometric method for the
determination of tantalum content
GB/T 223.59, Iron, steel and alloy - Determination of phosphorus content -
Bismuth phosphomolybdate blue spectrophotometric method and antimony
phosphomolybdate blue spectrophotometric method
GB/T 223.60, Methods for chemical analysis of iron, steel and alloy - The
perchloric acid dehydration gravimetric method for the determination of
silicon content
GB/T 223.65, Steel, iron and alloy - Determination of cobalt content - Flame
atomic absorption spectrometric method
GB/T 223.68, Methods for chemical analysis of iron, steel and alloy - The
potassium iodate titration method after combustion in the pipe furnace for the
determination of sulfur content
GB/T 223.71, Methods for chemical analysis of iron, steel and alloy - The
gravimetric method after combustion in the pipe furnace for the determination
of carbon content
GB/T 223.73, Iron, steel and alloy - Determination of iron contents - Titanium
trichloride-potassium dichromate titration method
GB/T 223.84, Steel and iron - Determination of titanium content -
Diantipyrylmethane spectophotometric method
GB/T 228.1, Metallic materials - Tensile testing - Part 1: Method of test at
room temperature
GB/T 231.1, Metallic materials - Brinell hardness test - Part 1: Test method
GB/T 702, Hot-rolled steel bars - Dimensions, shape, weight and tolerances
GB/T 908, Forged bars for dimensions, shape, weight and tolerances
GB/T 2039, Metallic materials - Uniaxial creep testing method in tension
GB/T 2101, General requirement of acceptance, packaging, marking and
certification for section steel
GB/T 4162, Forged and rolled steel bars. Method for ultrasonic testing
GB/T 6394, Determination of estimating the average grain size of metal
GB/T 6402, Steel forgings - Method for ultrasonic testing
GB/T 8541, Terminology of forging and stamping
d) Non-vacuum induction melting + electroslag remelting;
e) Electric arc melting + (external refining) + electroslag remelting;
f) Electric arc melting + (external refining) + vacuum arc remelting;
4.3 Supply status
4.3.1 Bars and forgings can be delivered in hot-rolled or hot-forged state, and
can also be supplied in solution treatment after forging; bars can also be
supplied in polished or turned state after solution treatment; the supply status
shall be indicated in the contract.
4.3.2 When bars and forgings are delivered in the heat treatment state, the heat
treatment system is shown in 4.4, and the heat treatment system shall be
indicated in the contract.
4.3.3 When it is necessary to supply in other heat treatment states, it shall be
decided by the supplier and the buyer through consultation.
4.4 Heat treatment
The supplier stipulates the heat treatment process of the product or sample in
the purchase contract or agreement according to the product use requirements:
a) System I. Homogenization: preserve heat at 885 °C for 24 h ± 0.5 h, air
cooling; aging: preserve heat at 705 °C for 20 h ± 1 h, air cooling.
b) System II. Solid solution: preserve heat at 1 150 °C for 2 h ~ 4 h, air cooling;
aging: preserve heat at 845 °C for 24 h ± 1 h, air cooling or furnace cooling
to 705 °C or below within 2 h or less time; preserve heat at 705 °C for 20
h ± 1 h, air cooling.
c) System IIII. Solid solution: preserve heat at 980 °C for 1 h, air cooling;
aging: preserve heat at 730 °C for 8 h, cool to 620 °C at 55 °C/h; preserve
heat for 8 h ± 0.25 h, air cooling; the total aging time is not less than 18 h.
The cooling time of furnace cooling can be adjusted to ensure the total
time.
Note 1: The above heat preservation time is the heat preservation time after
the sample or product has been heated through.
Note 2: The temperature uniformity of the heat treatment furnace does not
exceed ±10 °C.
4.5 Mechanical property
Bars or forgings shall be submitted for acceptance in batches. Each acceptance batch
consists of bars or forgings of the same specification or drawing number, the same
production batch, the same melting furnace number, and the same heat treatment batch.
6.2 Inspection items
The inspection items and sampling quantity of bars or forgings shall meet the
requirements of Table 3.
6.3 Re-inspection and determination rules
6.3.1 When the chemical composition analysis result is unqualified, re-sample at the
unqualified position, and re-inspect the content of the unqualified element. If the re-
inspection result is still unqualified, judge the batch of products as unqualified.
6.3.2 When a certain test result of mechanical properties is unqualified, take a double
sample near the original sampling position, and re-inspect the unqualified item. If the re-
inspection result of one sample is unqualified, judge the batch of bars or forgings as
unqualified; for forgings with unqualified mechanical properties, it is allowed to have a
re-heat treatment once as a new batch for acceptance.
6.3.3 If the tensile properties the bars or forgings are qualified, the hardness shall not
be used as the basis for product rejection.
6.3.4 When the macro-structure and microstructure of bars are unqualified, re-sample
at the unqualified parts; if the inspection result is still unqualified...